HELP. Insulating a Solid Stone Farmhouse... We need your opinion ASAP
ฝัง
- เผยแพร่เมื่อ 28 ธ.ค. 2024
- We have a pot of 3 options (below) for insulating the gigantic old farmhouse, but we're struggling to get reliable advice on which way to go. There is absolutely no consensus online or offline, so not screwing up this part is a bit harder. Solid walls are always tricky to insulate for reduced energy consumption, and with the scale of this huge property, the decision-making is even tougher. The complex shape makes all options difficult, but we need to pick the best way forward within the next week or two.
On the table is:
➡️ Option 1: External Wall Insulation (EWI) onto the solid wall (stone)
➡️ Option 2: Internal subframe with all modern materials inside
➡️ Option 3: Internal VPM (breathable) boards and/or lime-based insulating plaster
(if we missed one, please shout it out!)
The main factors to mull over are the exposed stone internally, plus many original features lost in Option 2 and 3, vs external fabric disruption from Option 1 - oh, and the cost!).
If you have experience with any of these three, we'd really appreciate a comment with your thoughts before the end of April 2024 🙏
(Not insulating isn't an option for us, and with the climate changing, we need to try to future-proof a little bit where possible)
🚨 Subscribe & hit the bell icon to never miss an update.
🙏 Supportive comments with thoughts and prayers are appreciated 🫠
🔗 IG for micro-updates: / sht.farm
🔗 The dog stuff: / thatphotographyspot
AMAZING responses on here and lots of signposting for advise too, so much information - thank you all for taking the time to share your experiences 🙏
Only to help you get ahead in life. We all struggle.. If you have your own land & get the house mortgageable, you will be on your way. One other thing is to get yourself a tractor, trailer and a 3.5t mini digger. Do the work yourself. Good 2ndhand gear out there. With a good team of followers to help you save money, to spend on better things later..... Good Luck from New Zealand.... I lived in the UK for 20 years....
For some further research (if you haven’t already come across them), have a look at 2 companies; Ty-Mawr and Ecological Building Systems. Both these companies focus on insulation systems for all applications, roof, wall, floor etc. which are breathable and sustainably sourced. Within my architecture practice based in Oxfordshire we typically specify from these two owing to breathability for a building like your farmhouse. They are both helpful over the phone and you can talk through the options.
I'm sure you have, but have you guys come across Historic Environment Scotland? They have really good videos on TH-cam and a brilliant website explaining these types of options. They also have plenty of case studies where they have used different types of insulation etc etc.
REALLY worth getting in touch with them
We live in a 200 year old plus farmhouse in very wet west wales. It’s about 2,200 square feet with solid (thick) stone walls so lots of similarities with your house.
My vote would be as much lime as you can do everywhere. We’ve got a mixture of lime render and plaster on the house and it keeps the house perfectly dry.
Having said that we’ve also combined it with underfloor heating on both floors linked to a ground source heat pump - and two wood burners in the centre of the house for when it really gets cold.
What we’ve mostly learnt from old houses is they need to breathe, which is why I think lime, good heating and ventilation are so important.
I've lived in thick stone, old Scottish houses for years, and the best thing you can do is bugger all. Don't mess with the walls. Fix and insulate the roof. Double and triple check every single door and window for the slightest draft, they are the worst. Fires are great, coal is more efficient but wood has soul. There are some high tech wood burning stoves with bells and whistles, like the wee one in the cottage. I near had a heart attack when you said you were going to bin the Aga.
You can run the pipework and hang the rads off internal walls and run a boiler, probably fuel oil if you're as remote as we are. As long as the boiler is up to date they are quite efficient. Most of our rads are turned off, and we run a couple early morning and before bed. If it gets proper chilly, light the fire. Check all the windows for drafts.
One of the best things you can do is identify your most used. exterior door, and put a wee porch on it. Blunt the wind, even better if you add a second door as an airlock to stop the heat gettin oot, or the cold gettin in. Check all the doors and windows for drafts.
If you've got decent fireplaces, make sure ye can shut the lum (chimney), stop the wind from howling down. Just remember to open it again.
Curtains. Bloody big floor to ceiling curtains, none of the fashion nonsense, and use them when it gets chilly, usually in February.
Mould and stuff is only a problem if the house can't breathe, if you try to lock it in. Make sure yer windows are vented, close em on the coldest days if you need to, or if the wind is blowin hard.
Honestly, once yer in, it keeps itself nice. It wouldn't surprise me if it's just shy of 20C all winter, I spend most days in just a tshirt. Just make sure you've checked all the doors and windows for drafts.
Hi guys. From a stonemasons point of view. Take the paint off the house and do a full lime mortar repoint. Any cement pointing will hold moisture inside the building. If you want to paint the building make sure you use a lime wash or lime based paint. Insulate the roof and look at using lime renders on the inside to keep the room sizes.
Make sure that any room that has had a fire place in it that there is adequate ventilation. If you need masonry contacts i have plenty in central and some north of scotland but not so much south
Good advice
A stonemason too, excellent advise there, also regarding painting inside clay type based paints are good too.
Gets bit expensive but is best, nice going go steady looks an ace place.
yep watched so many stone buildings, roof, strip walls and only paint with line and repoint, check all drainage and ensure it’s stays away. internal tank base of floor and insulate, and insulate roof. roof insulation needs to be breathable with an air pocket behind it. no cement only lime based mortar
Thick stone walled houses need to be lived in. Heat up the inside, insulate the roof, seal & insulate the floor. Leave the inside stone walls to breathe. Don't waste money unnecessary. Get the roof finished, inside sorted and live in her and fix one room that will be yours, bathroom then every other room as you do them.... you have heaps of room. Also keep the water around the house away from the house, ie: tiles or drain flow... I love watching your journey...😊😊
Absolutely agree with this….but as a personal choice I’d also remove the paint from the exterior and repoint where necessary, the stonework is lovely!
I would want to know if the paint used over the years on the exterior is breathable if not the damp in the walls would not be able to breathe properly. This maybe the cause of blistering on the outside where the paint is flaking off.
Remove paint, white wash, insulation in roof
I second this
Agree insulate roof and floor take the paint off outside ,let the house breath and dry out Wet stone/mortar will conduct heat , Save your money for a economic green tec heating solution
Agree with comments on letting the walls breath. Would vote for the internal natural solution. Insulated lime plaster with cork for the internal walls is a great single application option. Not cheep but in key rooms will add insulation but without much loss of area and allow you to keep the features
We have a farm on the edge of the Dumfries and Galloway national park it is listed so it’s a little harder to use modern methods we have been at it for the last 2 years this is what we found starting out side we had concrete render as well as a plastic storm paint the paint was been pushed off with the damp the concrete held the moisture in the walls that was also been pushed off once removed and repointed with lime mortar the walls dried 8 ton of concrete chopped off 6 ton of lime mortar pointing and the house lost its cold chill we also added sheep’s wool insulation under attic floor this also made a big difference we have come to the conclusion that a base of scratch coat lime plaster then insulation and plaster boards on framing may the best solution the vapour will pass into the wall and the lime plaster will stop condensation forming on the stones
We haven’t completed this method so cannot give you the results some of our walls have been lime plastered onto the stone which also appear to add a bit of insulation. Once you have heat in the building it holds it well it’s the leaks that need addressing like under the floor and in our case old sash single glazed windows
Get rid of the plastic paint lime wash it you can get water repellent lime wash with linseed oil in it or tallow let the walls dry hope this helps good luck on you journey
Hi Guys, Architect here - there are multiple ways of insulating the walls however its STILL contested which way is the best in terms of cost, longevity and practicality. From most builders and developers we speak to, the less likely option to cause issues in the future is also the most expensive;
Remove all the external paint, repoint the mortar, leave a minimum of 50mm cavity on the inside wall, construct a 150mm timber frame, fix OSB to timber frame with a breather membrane between the existing wall and timber stud, full insulate the stud with a mineral wool insulation, close the timber frame with OSB and finish with plasterboard. This internal wall system will still allow the existing wall to breathe and any condensation or water that penetrates the existing wall will be able to evaporate without damaging the inside of the property.
One last thing - ventilation is key. If you are replacing any windows make sure to fit them with trickle vents, use mechanical ventilation in habitable rooms, etc.
Hope this helps! Keep going, you guys are doing great!
what he said
This is pretty much word for word what I would have recommended based on the experience of renovating my family home with my parents 10 years ago ... That said we had family friends who had a very similar property and stripped off all the outside paint then applied a lime based render which seemingly allowed them to keep lots more of the original charm internally
My added suggestion is a large glass window for those areas like this that you want to reveal the stone.
I live in a solid brick farm in northern Italy, it's hot in summer and very cold in winter! My late father was a builder but focused on decorating..... If I were you I would double the roof insulation, the ceilings upstairs are fucked being polite! Put in a vapour barrier, next work your way round and fit good quality new windows double or triple glazed... Next insulate the ground floor through out... This can be roon to room as you renovate.... Next you need to decide on interior, do you want stone cottage look or grand farmhouse? Or both?? If it were mine I would treat each part of the building as it was built, cold stone cottage, keep it stone, this you can limewash or lime render. Do this downstairs as well as upstairs.... In the newer grander parts keep what you can lime render and lime wash... In every room that has a chimney, open them up you do not need to have a little open fire alight in a poky box room. But an open flue that is capped with a ventilation cowl and a hit and miss vent at the bottom, this will allow air movement, the better the air movement the less condensation... In rooms you won't use as much but will use, personally I would fit a log burner, that includes your main bedroom, living room, kitchen/dinner, study etc.... these obviously won't be alight every day all day. However from experience having a good quality log burner in a downstairs room using a flue that passes through the bedroom above, is enough to keep it damp free and while cold it doesn't have damp or mold and can easily be slept in.... Master bedroom have a log burner, use it in the coldest night's... Bathroom have underfloor heating electric... And have an opening window or roof light... Heating personally , I would set the heating up in zones and have maybe a boiler stove to heat the kitchen dinner and the rooms around and above... Then do the same in the other parts that are used less.... Again underfloor if you can stretch to it.... Finally the outside pressure wash it to fuck, get it back to it's original non painted state, and cement pointing hack out/off .. do a proper repoint with lime pointing. Leave the stone exposed and allow the house to shed the damp open windows when it's warm enough to do so. Maybe get a big dehumidifier in and help it dry faster...... A Rayburn run on coal and wood will be cheaper than oil or LPG.... We have a large wood burner in the open plan dining room/hall way, staircase... This keeps the cold at bay. Once it's dry you can limewash/render the outside if you prefer...... Face facts it's never going to be a Barret house to run, but by heating the bits you use all the time and secondary heating the other bits it won't be hideously expensive..... Open fires log stoves heat the fabric of the building and keep the air moving round so keeping damp and mold to a minimum... Mold cannot grow on lime , so only use lime based paints..... Good luck! Love your channel....
My wife and I, both in our mid 30's bought a 1840's stone/cob cottage in Cornwall 2 years ago and have been renovating ever since. Like yourselves, we contemplated the various methods of insulation and trying to maintain internal temperatures, but ended up deciding to go down the traditional route. As everybody kept saying, the building needs to breath to prevent issues. We started in the main living space, which we stripped back to the stone work (The cottage had been cement rendered internally and externally post WWII) and found a multitude of issues (3 meter rotten lintels, rotten skirting boards etc.). We also didn't insulated the floor, but did plaster the walls with traditional lime paster (non-insulated). Having done this, we now have decided that the upstairs will be coated in an insulated lime plaster. The main reason being that heat rises and our main source of heating is our large log burner in the main living space downstairs. We have found that the temperature of the walls or generally the building doesn't cause any issues with condensation etc, as long as we maintain and control the relative humidity (RH) of the building. By maintaining the correct RH levels, we have had no mold or damp patches anywhere since, especially considering that the range of internal temperature fluctuates a lot, mainly because we tend to have little to no heating on during the day and only have the log burner on during the evenings. Most experts saying that you should try maintain the temperature in the walls, and i do agree, however when like yourselves your walls are close to a 1metre thick, it takes a lot of heat (and with that comes expense) just to get them warm, let alone keep them warm. I am not an expert, but we have found that controlling the buildings RH has allowed us to do reduce our heating costs by 50%, however we do live in a slightly colder house now, but we aren't so bothered about that. Doesn't take long to warm up in front of the log burner.
With regards to the downstairs floors, i do regret not ripping up the old floor and starting again (the cottage is build on bedrock) with trying to add insulation, even if this meant raising the floor height, as this is the one area that is constantly cold, we have tried mitigating this by installing engineering floorboards with thin insulated matting, which has helped slightly, but my recommendation is to spend the time at the beginning of the project and do the flooring right. Adding in underfloor heating, heated by air source heat pumps, may be a good way of allowing heat to be constantly pushed into the property, reducing the need for central heating etc. I am still contemplating ripping up our floor and redoing but would come with a large cost and time. If you can get your heating correct, then having fully insulated walls may not be required. We have found its always a catch 22 situation and no matter what route you take everybody has there own opinions, and yours is never right. You just have to do what will work for your building and your lifestyle.
Best of luck. Look forward to seeing more videos and your progress.
These houses were never meant to be insulated or indeed waterproofed.
The moisture level will vary due to time of year & they need to breathe.
Firstly, get rid of that paint.
Then, repoint with lime mortar & if you wish limewash or lime render.
If you "really" want to insulate, then you could batten the interior walls & screw insulated plasterboard over that leaving a decent air gap, but then you'll need extra ventilation.
If you insulate on the outside, bear in mind you'll need to extend the eaves!
Overall, you are best off having a good extractor fan over your cooker & in your bathrooms & favour a wood burner over central heating as the air will be drier.
All the best from @HowardsPortugal
Just finished renovating a 200 year old cottage with stone and cob walls. We went down the wood wool board, sheep’s wool insulation and lime plaster route. Just been through our second winter and we don’t have any damp or cold issues. We’ve learned that the key is to keep a constant temperature (albeit doesn’t need to be high) and making sure it can breathe.
You did it correctly
Insulated roof to modern standards. 50mm ventilation gap on cold side. Thermal lime on the walls, wool based insulation with a vapour barrier in the floor. Double glaze windows. Make decent plans for ventilation. That’s what I’m doing anyway! The lime need not be that expensive if you learn to do it yourself.
I am impressed at the idea of learning how to do Lime yourself - do you plaster already, Can I ask? The concept of a Lime Crete floor sounds quite achievable, but I’ve always thought plastering was not really a DIY task unless you’ve got a background in the same?
We live in an old (possibly badly) converted barn - rented so not 100% but I think we have option 2 here. Not sure I would recommend, our place wasn’t massive to begin with but it’s a lot smaller than it could’ve been obviously our windowsills are huge and I have to climb onto alsorts to reach handles to open the windows. The walls arnt strong enough to hood up much, no wall kitchen units, no mirrors, it couldn’t hold my bracket to hold up a cordless dyson before I even put the hoover on it. Many picture frames won’t stay up but a few have. It’s also mouldy in random places where there must be gaps in what they have done. Loving watching this process! Good luck guys
Old stone farm had the internal frame stuff on the outside walls. Lost loads of space in each room and if you touch/knock on them its so loud and echoes. It was part of a grant so we had no say. From what you said the lime sounds best but I do love the og look of the outside
They also put giant vents in which has made all of downstairs drafty
Our old Welsh farmhouse (dating from 17th to 19th century) was renovated in 2013. We didn't mind the stone being covered internally, so went with internal insulation/boarding. Floors were insulated too - underfloor heating downstairs. It has been great. The house is warm, although it is definitely not air-tight. We only had to put a few new windows in, so the older UPVC windows are a bit draughty and there are 2 massive fireplaces which encourage airflow 😀. No damp or mould, but we keep the house warm/aired, uncluttered and clean. Would do the same again.
Pressure wash the exterior, repoint with lime mortar, re white wash-not paint needs to be breathable as ya know. Dig the floors out, proper damproof and put in under floor heating, props to your common sense on not wanting it 30', go for warm air/johnson and starley system, as you'll need plenty, over spec to "give some to the walls" was a good way it was explained to me, repoint insides n varnish stones, and only lime plaster a few feature /practicallity walls. If you got ground look at ground source, or plant a small woodland n go wood fired water/thermal store system. Warm roof insulation, do not wrap/clad/create voids anything!! Ive helped on alot of barn conversions n old farmhouses here in cornwall/devon, both 1st time and rectifying what youve (very well) explained, above is the best of what ive seen, just not done together🙄
All i can say as a building contractor, specialising in historic properties is do not go for option one (blanket)
Does it not depend on how breathable it is? Kingspan would be a bad idea, but wood/hemp/lime combos should work surely?
We are in the process of restoring old Scottish farm cottages from 1760. There’s 3 cottages that were knocked through into 1 house about 100years ago or more. At some point someone had installed insulated plasterboard with foil backing all around the inside of the house. The damp problems here are unbelievable! But that’s another story. I’ve started ripping out the insulated plasterboard and found the walls behind them are dripping wet to the touch. They are now drying out nicely as they can breath now, but whoever originally installed it put vents through the lower sections of the walls to the cavity behind the insulation, in an attempt to ventilate the cavity behind the insulation. This however never worked. The reason it didn’t work is the air had nowhere to flow to. The cavity at the top of the walls was stuffed up with glass wool insulation in the loft, and even if it wasn’t, the roof is very old type with no ventilation. When we renovate this we plan to have a full vented cavity that goes up to the eaves and then up to a vented ridge along the roof. This should hopefully allow airflow and work a lot better. I haven’t had a chance to read all these comments yet but thank you for posting this! We are in the same boat 😂
The vent through the lower section were they internal or external?
Really interesting to hear a how not to As Well as a how to! I’m guessing that you had no idea how wet the walls were until you took off the internal insulation?
You are asking an excellent question. First, the technology has advanced so much in the past few years to be amazing. St Gobain in France has created several attractive solutions that have been used on many older stone buildings (with walls as thick as yours check out TH-cam). Second, you mentioned heating, you should consider in-floor heating because the scale of the house will ensure that the rooms are warm.
Any product that you install outside a building will have a limited lifespan, far more than interior solutions. The best option is two-fold, a solution that helps with humidity, and makes heat more even. Also, a substantial source of humidity in your building will be the footings (or the lack thereof), installing new french drains outside may make the most difference in the comfort of the house. Allowing winter rainwater to be removed quickly from the foundation will almost certainly have to most impact on the humidity.
The third option is to use a combination. As you indicated you would like to retain "some of the classic stone features" inside the house, why not pick walls or even parts of the house that will be insulated from the outside, it may add to an eclectic look to the house that will make it seem less massive (it is after all a very big house). Best of luck very impressive
Excellent suggestions
Good suggestions. Mix it up. Get rid of that rain water.
I can offer experience on two of the options mentioned. We live in a rented farmhouse in similar wet/mild climate, in rural Herefordshire. We have 3 examples in the house across the various ages. The oldest section of the original farmhouse from 1700’s is lime plaster internal, which is nice and cool in summer, but cold in winter, exaggerated by some single glaze windows in that north side of the house. The next section of the house built 1880’s has had internal insulation added 10 yrs ago with an extension conforming to modern standards. From speaking to the landlord it sounds like it was a very airy cold house for him growing up. There have been a number of issues since we’ve been living here, little critters mice and rats living in the wall cavity, so I’d avoid the frame option, also condensation in both of the older sections of the house. There’s been some leaky issues at the joins of the extension too, which you have lots of experience with haha.
The newer section with modern building standards can get too hot in the summer. So we just play musical rooms and spend more time in certain rooms depending on the weather / season 😂
Love following your story guys, we’re not far behind you.
would make drainage around the house a priority and ventilation inside. Insulate the floors and ceilings as well as the roof to the max. Stone walls are obv big heat sinks but you can use that to your advantage too. In floor heating like several other people have said.
Your walls may be thick enough that they contain enough thermal mass that you may just end up chasing your tail with moisture problems, trying to insulate the walls. It may be better to super insulate the floor under the house and the roof.
There's no question of thermal mass. It exist. But thermal mass in itself doesn't lead to moisture problems. There are potential moisture problems, as with any heated building.
@@dper1112 thermal mass does not lead to moisture problems but adding coatings or insulation means one side or the other can not breathe and manage the moisture passively.
I live in a mid 19th century house (stone walls), we had huge damp issues and used a product called Cork Spray. This was sprayed directly on to internal walls and then plastered over, solved all our issues.(not to expensive and I think you can also get it done externally) Best of luck 👍
I know a few that have lived in solid wall houses and everyone says that the best thing you can do is heat the home. Whatever open fire possibilities you have you need to use. Not just a few hours either, you are looking at days of heating just to get it going. You can seal the outside but you will be better off removing the current wash off the outside building before starting again.
I truly enjoy watching you guys and it's the only channel me and the Mrs both watch together.
Best of luck!
Hello, you’ve purchased a lovely homebuilding with heaps of character. I bought an old farmhouse in Lancashire. It was a shell and very damp, my dad and ex builder gave me a checklist. It was a simple approach, roof, flashings, gutters, windows With correct reveals and drains, no plants climbing up the exterior, ceiling insulated, damp proof course above ground level with an investigation to damp in foundations. I had similar issues as you when coming to the painted exterior, in the end we stripped off what was there and applied a lime based finish on nylon mesh. The stone walls on the inside lined with a breathable barrier insulation plasterboard. We insulated all interior walls and floors and heated flooring in bathrooms and toilets. We retained the open fire downstairs and put a heat transfer system and wet back central heating system. so in summary check the basics of the house and proceeded on a solid plan.
This was a great video u have read a lot into the options. I have no experience other than staying in a hotel in Austria which was a 14th century castle and it was insulated on the outside. Ok the benifits is that the material in the walls hold the heat in the house. So u can use the nderfloor heating and get benifit there. The disadvantages are before insulating the outside u need to make sure the wall is perfectly flat so there are no air gaps between the insulation and stones. And you will have to extend your roof out and over the external wall insulation. And you need to insulate the top of the wall. You can break the cost down and do a wall at a time and it’s easy to do as well. To control the moisture in ur supper insulated air tight house u need to look at mechanical heat recovery this will keep moisture levels lower to. Insulate the inside of the walls it’s cheaper but there’s not to hold heat so house will cool down faster but heat up faster just like a timber frame house. It’s a tough choice
Wishing you good luck and some good weather
Option 4 install solar and wind generation with battery storage or large heat storage..reduced power costs ,run your heating with long term savings..off grid or semi off grid , electric car charging etc..
Insulate the roof and floor, and strip all of the exterior paint and do a proper lime render - which will help the building breathe and allow the stone to dry out.
Put in french drains and re-route the water away from the buildings, and do some landscaping to help with drainage.
Get started on stripping the exterior first!
I only have experience with external insulation which once rendered. It was on a 1700’s house with no foundations and very thick walls. We did it to save space inside as it wasn’t a big house but it made a huge difference. It took months for the stone to fully dry but wow, it went from 8c on average in the kitchen to 15/16c average. Also at the same time put 100mm insulation on the ground floor with new wood flooring. Then heated the house with just 2 single wood burners and it was 95 square meters.
As the house was always rendered it don’t look much different other than it was some of the shaping of the stones. This was minimal compared to the saving on heating.
Your videos are great keep it up and don’t worry to much it can all be fixed 👍🏻
As other have said get rid of the paint & let the walls do their job. Improve your windows & roof & insulate the roof well. Add a heat recovery unit which will provide clean dry warm air while also removing the need for trickle vents & drafts. Good luck 👍
Thinking about it, option 2 is the best bet here because not only will the farmhouse be insulated, it will have the finishing boards installed which will save you time and maybe a bit of money too. It would be sad to lose the features that you love but in this situation, it is a kind of what is in the houses best interest that has to come first. Loving this series guys, please keep the videos coming.
The problem with internal insulation is you loose the thermal mass of the walls. I have solid brick walls in my house heated with log burners. The walls absord the heat then slowly release that back in to the room when the fire has gone out.
Hmm, thanks! I knew that…but I hadn’t really thought through the implications. I’m planning on 50mm kingspan ewi…but want to make inside breathable. Looks like I might not do wood fibre Iwi in my room with a stove to improve the u value with the ewi… thanks!
We did this with our 350year old Scottish (Ayrshire) cottage only 2 years ago. Almost didn't get a mortgage on it out walls were so bad. They were covered in latex paint and house had never had heating. In the end we Sandblasted all internal walls and external where not rendered. Tips we learnt
Pointing ain't hard can do it yourself but get good lime (place in Glasgow is good can pick your colour and chunkiness- mason motar and conserv online was good ) remove all concrete pointing inside and out. We left the internal exposed and external we have render already out front but at the back we are lime rendering and mold wise don't get any not even in the bathroom where we have exposed stone external wall we made sure to keep floor and ceiling spaces to allow the house to have air flow. Hate to say it but we found our flooring insulation made more difference than ceilings 100% worth while. Conserv also had a spray on sealant for internal and external walls, that helps keep dust down makes the walls brush able for dusting(super handy) but makes them less lose if you don't scrape out all the old lime
For living with exposed stone, we keep the heating on all year round to never drop below 15° we have found through trial and error if you keep the house at walls warm the house stays warm, you let it get cold it stays cold for ages. We don't have any issues with mold using this method.
Got more if you want haha 😅
Really interesting thanks! So you sand blasted off the paint inside? I’m currently trying to get gypsum plaster off solid brick walls to try to dry them out a bit from the inside… And it’s proving really difficult to get the last bits off. Can’t as I like the idea of internal sandblasting, but I can definitely see the logic!
Option 4 install a solar and wind generation set up , check out the Archimedes wind turbine..think about battery storage or a large hot water heat exchange storage, go off grid or semi off grid , run your heating with long term low cost..
I bought a stone house 2 years ago. 1st winter, oil boiler and no insulation. 2nd year, IWI, and a heat pump. With iwi, house warms up fast, but also cools fast, with no thermal mass. Heating bills cheaper, but underfloor insulation will make any house feel warmer. I miss, last years ability, for the walls to slowly cool down. I would have gone ewi, yet live in an area where not possible. Your house is large, so iwi will not be an issue, space wise, yet, lose the features. In your place, I would do EWI, all the way. Diying this, is very possible. Add as much as you can, then keep stone feature walls inside. Regarding internal moisture, ventilate, ventilate ventilate look into mvhr, while the ceilings are down. Get a ground source heat pump, and you gain, everything. Low, slow, cheap heat, keeping fabric as wanted, Abd importantly, making the most of your massive heat sink, stone walls. Which makes it even cheaper. Definitely disagree with not insulating the floor first. Please do it, or you will rip up decorated walls to work around it. Underfloor heating. If you don't believe me how much insulated floors make the biggest difference to feel, take some insulated foil board, Shoes off. Stand on it outside. Then stand on a paving slab. The difference is immediately apparent. Keep feet warm, the rest of you is easier to heat.
We did option 2 on an almost identical full renovation on a wee Scottish farmhouse. It had lots of advantages, and we did a stone floor with wet underfloor heating which was amazing even at minus 20. The only BIG downside with having the internal subframe was wee critters. It was especially so bc ours was attached to an unconverted stone steading, but basically having a gap between 2 wall structures is heaven for mice and more. So if you do go that route, you have to 110% belt and braces any gaps/conduits/mortar etc and often reinforce with steel mesh etc.
I so didn’t think of mice! I’m loathe to do battened IWI in my 20’s semi because of interstitial condensation & mould…but now you’ve mentioned mice, living near à field, it’s going to be aerogel or wood fibre straight onto the walls for sure!!! Thanks!!!
These videos are great, could easily watch one everyday 😊
Scottish government have published a few really good research papers on this topic. I internally insulated a solid brick wall house with wood fibre and lime plaster with very good results. It is a fully vapour permeable build up but that isn't completely necessary, it was just easier for me and was more forgiving than getting a fully complete vapour control layer. I've had no issues with damp and the insulation has overperfomed compared to calculations.
It is a balance of insulation, ventilation and air tightness. I also installed a mechanical ventilation heat recovery system to keep warmth in the house and humidity under control.
I think with thick stone walls, a dry stone wall is going to be pretty good so you wouldnt need much internal insulation. External insulation im not sure is as good here as you'd have such a massive heat sink in the walls, would you feel the benefit compared to internal insulation?
With the walls repointing and roof repaired the walls should keep water out very well as originally intended (letting water in and out as you say)
I have lived in many old stone properties and they are the best if treated with respect. Just first class ordinary decoration inside and out. Fit excellent doors and windows. Insulate roof spaces to the maximum but install ventilation above. Excellent ventilation and extraction in kitchens and bathrooms. Keep inside temperature to 18/19 C and put more clothes on if you are cold !
I am really enjoying your journey .
Morning, I've halfed the heat loss oh my 1881 Scottish stone built house over the last 3 years. I'd strongly advise against PIR, even in stud walls, it's an awful product. Internally I'd suggest a wood fibre insulation with line render top coat and breathable paint, or similar if doing external. Wood fibre is a lovely product. I've also used it in the suspended timber floors and the eaves, with 400mm loft insulation. I know have a heat pump, the ideal solution. Any Q's just ask.
I think you need q combination of solutions. Also consider positive input ventilation which can eliminate condensation and mould
Two thoughts, do you want to prevent moisture from coming in, or get the water out (two different things). If you spend a lot on a partial prevention method, you might want to rethink.
I live in a stone house in France, the previous owner went for option 2, but kept small parts of external walls bare (near the fireplaces) and internal walls when beautiful. The first thing I did is add access points to be able to fight the living stock within the walls.
Second thing I did was add an air to air heat-pump. Not as main but auxiliary heating, it works great (and fast) for heating, cooling AND drying. Together, it solved most of our problems. Perfect? No, but relatively affordable and a huge increase in comfort. In my 50m2 kitchen the heat-pump is able to raise the temperature within 15 minutes from 14 to 20C. Then I light up the wood-stove.
Keep in mind that a lot of moisture is created within the house (unless you stop breathing). So pay attention to ventilation. Forced ventilation in combination with air heating and a heat recovery system might be a solution as well.
And of course the simple maintenance on gutters, a French drain and so on will cost much less and not deliver perfect results. Kind of fighting moisture by death by a thousand cuts ;-)
Hello guys….really enjoying watching your progress. We used to live a cob house and I would think stone is very similar being a natural product. If it was me I would leave any wall insulation and concentrate on the roof, triple glaze the windows and get some heating into the place. There’s is reason it’s lasted so long and that’s because it’s been well built in the first place. Consider speaking with neighbours or previous owners and see what their thoughts are. I think you could save shit loads of money and channel into more cost effective and insulating products. You could consider insulating the ceilings with insulating plasterboard to make rooms cozy. Keep up the good work!
Got a similar issue with the thick stone walls. The highest vapor areas are bathroom and kitchen which you would install extractor fans. Make sure the windows have trickle vents in so there is a constant air flow in the house. Pir insulated plasterboard can be dot and dab on the walls to save space ( make sure you silicon the joints to complete the vapor barrier). If you wanted to keep a few features in the house ie stone walls then install a MVHR unit in the loft and if the moisture level is still higher than 60% then install 2 MVHR units. This way is the most cost effective and least labor intensive.
We live in a stone house in Ireland that was renovated in the 1970s (pebble dash and aluminium framed double glazing in accordance with the stipulations of the government backed renovation grants of the time) We have gone down the conventional route and dry lined (35mm insulation backed plasterboard.) Have also installed a moisture barrier and insulation under any floors that have been dug up. Weve worked on a room by room basis with tje exception of replacing all windows woth modern triple glazing and all external doors. We also opened the other flue and installed a decent woodburner (already a wood burner in the main sitting room that is plumbed into a back boiler to supplement hot water/heating (we also run an oil fired range which is on all day on low in winter and largely off in the summer) Hope some of this helps. Really enjoying watching the project!
Every person exhales 3 or 4 liters of water per 24 hours, = problems can arise so keep old fire place in down stairs room ,put in duel fuel burner = house can breath and mould is difficult to grow due to ventilated system of air movement due to moist air ls heavy = it falls to ground floor = will find its way to the fire to rise up the chimney with heat provided you have a balanced flow system what that means is allow air in via an upstairs window Small but ajar only =air pressure stays the same as outside = a balanced flow system ( like you solid walls have to breath or thy will become permanently damp =skimmed with lime render = it will breath just ideas is all hope it helps
Get the roof insulated l put 8 inches kingspan in mine. Double or triple glazed windows. Made big difference in mine
We had the outside of our stone walled house insulated about 6 years ago.
Advantages were no disruption to inside and several walls were only scratch coated at the time, so finished off the exterior.
Disadvantages are you have to heat the thick stone walls as well as the inside space. We did manage to secure a 75% grant on the cost, so it made far more sense.
On balance if I wasn’t living in the house and doing the work myself I would go for internal insulation.
That makes sense. External insulation and protection makes the most sense on preservation of the walls and minimal maintenance but now you have to heat hundreds of tons of stone.
New roof with breathable membrane, make sure internal floor levels are not below external ground level- reduce the external if that’s the case or remove from the walls, like a little trench then see how it dries and what happens. We’re in stone house in north wales - been in nearly two years and just finding out what needs doing and how you use the house- living in it with heated inside will help don’t rush to do anything or you’ll end up compounding problems for later on
We have just renovated a 400 year old Manor. Allow the house to breathe as it was meant back in the day.
New windows, insulate the roof, and get a good heating system. Things start to go wrong when you start using modem materials on old buildings.
Hello we had the same issue in France. The fist thing to get right is the floor. We were lucky that the floor had been suspended with cinder. Block and preformed concrete beams. We used metal studwork apros 2 inches from external walls and infilled with vapour backed insulation batts.
For upstairs we had exactly as you have we used the same method but added 9 inch vents in each corner and then every 2 metres.
You will never stop rising damp, the walls are meant to breath. By stopping one thing you will create another. Never had a problem with the house even when left empty for long periods of time. Good luck with your new home. PS we plaster boarded with half inch board.
I believe that using lime plaster pointing on the outside, and building the insulation with inter wall allows for much more accessible to place all the electric, water pipes, ect. Thinking how nice the outside would still look and thinking of how difficult it would be to clean the walls with the rugged rocks on the inside,
Hello Shit Farm, insulation and covering up walls - you seem to have some very good knowledge of it. Whatever you do we are sure you will make the right decision. At the end of the day it will be a beautiful place to live!! We hope you keep battling on with it! We hope we live long enough to see it all finished!! Malc and Ann (ageing pensioners!!) North Lincs xxx
Experience of sandstone thick walled house, so slightly different (actually more porous) I would say the best option is to clear the paint of the outside and let it breath. Yes the house will take some heating at the start but will do well to retain the heat once you got it up. For instance if you were away for a few weeks in winter it would take a good two or three days to get a good lasting heat in the house but after that you would only need the heating on occasionally to keep it at a good temperature. Do a good insulation and the roof and floor and you will be good👍 the price of insulating the full house will cost you more than you would save in a lifetime. Maybe think about solar heating for a future project?
Me and my partner Just renovated an 1805 stone cottage in Cornwall 150m2.
I found that stud walling and 50mm celotex has made a huuuge difference in the warmth of the property as well as plenty of insulation between floors and new loft insulation to spec. Kitchen and front room we left the original floors down as I didn't want to disturb the Delabole slate to insulate below. Kitchen temp used to be 9/10 degrees within the hour as soon as you switched the heating off. Now it maintains a steady 16 with heating off and we only use the heating for max an hr a day. We are in a VERY windy location with no protection at the top of a hill also. Block any air gaps, they are not your friend!
Unfortunately you will struggle to keep all internal features unless you drop and refit once studs and new walls are up.
I've read some of the comments and its based on logic and experience, removal of all the exterior paint, insulation of both floor and ceiling, double glazed windows, French drains is a must, ventilation and heat for some of the important living rooms. Good warm clothing goes a long way as well.
In pretty much the same place right now too so your dilemma resonates! Have done a lot of research and as you have probably also found there is a ton of opinions on what is the "right" way. My present line of thought for my similar property is roughly this, reduce external moisture stress as much as possible so drainage/rainwater goods to pull water away-others have voiced same- and repointing (lime) both to reduce moisture coming in and also unwanted air infiltration. Whitewash and restoration of harling on certain parts to shed away as much rain borne water as possible. Internally kind of erring towards studframing-yes loss of space sucks- BUT with natural insulants/boarding to allow vapour permeability. Not yet priced insulated plaster on the hard as option but interested to hear that it is pricey!!!
Roof to get well insulated obviously but also with plenty ventilation to prevent moisture build up, that's where I've already had issues. Roof was reslated a few years ago with a "breathable" membrane...on the NE facing side-that doesn't get sun or wind in winter there is moisture build up due to lack of relative air movement. Both architect and slater overlooked slate vents " it's breathable,it'll be fine" Nope. Hence why I have went a bit ott on moisture mitigation planning. Will be looking at some sort of MVHR setup for the house interior as well.
Couple of quick points, have went on too long already! If you haven't already check out (www.) engineshed.scot/ they have a ton of case studies under the Publications tab. Also (www.) historicenvironment.scot have info. Both have specialists that may be able to advise. Best of luck and look forward to following your journey.
Using EWI is going to be loads of work if you want to avoid cold bridging. Moving windows out, gutters out, extending eaves and verges. Event that garden wall abutting externally will need to be removed. The other issue with EWI with such thick stone walls is the thermal mass in the wall. Your never going to warm the walls themselves up and they are going to absorb a lot of the heat.
Due to the size of the house, and the fact it's in Scotland, you don't really need thermal mass. Therefore I think internal insulation will be better but you risk interstitial condensation if you don't get it completely airtight. You then haven't got to worry about using costly alternatives to Gypsum plaster as you will be providing ventilation elsewhere.
You will need to insulate into reveals to avoid cold bridge which will reduce the window opening sizes.
Breathable isn't binary. The vapour permeability of materials varies. Although the stone walls will be somewhat vapour permeable if you cover it internally with a "breathable" insulation the stone will be less vapour permeable and you condensation occurring behind the insulation on the stone.
Given how much you have to do, I would focus your funds on roof and floor insulation, decent double glazed windows and doors, getting rid of draughts and getting decent mechanical ventilation in the warm humid rooms like the kitchen and bathrooms. Perhaps even some decentralised heat recovery in them.
For the walls I'd be focusing on just trying to keep the surface temperature above the due point. On the north side walls you could try and use insulating lining paper. It's not going to make much of a difference to the U-values but will reduce the risk of surfaces being below the due point. Tile all walls in the bathrooms.
I think you will need to accept that with an old house of this size in Scotland, you are going to be huddled round the fire to keep warm in the winter and will be wearing thick woolly jumpers throughout the rest of the house.
Good luck!
I would personally focus on ensuring 100% water tight. Roof & exterior (render) You have a lifetime to do the rest internally. With peace of mind that the property is in a good position to move forward to the next stage internally. Great videos & work best of luck to you both.
Option A definitely. 😊
I live in a stone building with 1 to 1.5m thick walls just stone on both sides and as long as it's not left empty and cold it's not a problem & you have a good heating system (that's not oil ect as this will just break the bank).
But if pointed inside or out with cement not lime that you will have massive damp problems on the coldest wall. Unless you are building a passive house with air management system all houses need to breath !
Original features to me are much more important that's why the house has charter and we love them.
Focus on what is required to make it mortgageable for now, jet wash & repoint in lime on the out side paint with a breathable pain like lime wash (to allow it to breath), insulation can be done later as and when required and you have more money
If it's not required for the mortgage don't do it yet stay focused on the short term goals.
The house will eat all the money you can throw at it plus more.
Sort out the roof and drainage.
Make sure outside ground levels are below inside floor level.
Remove external paint and and repoint where necessary.
Built stud walls with pir board and vapour barrier internally.
Allow the house to breathe
Greetings, my husband is a retired Journeyman Mechanical Insulator.. think Very Large Boilers and Chillers. The cold will continue to wick through the walls. Place a vapor barrier over the stone then as long as it will remain dry, use Rock Wool, Spray foam is always the best vapor protection but really hard to come by in certain locations. Mineral wool also doesn’t rot as easily if it gets damp and its contains a fire retardant.
Spray foam is a massive no
Option 3 two birds one stone so to speak ,then sand blast all the outside , great repaired roof with fantastic modern insulation your quids in with best results
We have no experience... But from what you've explained... Very very well... We would go with the external jacket. If you can stretch to that money wise... And it's your forever home... We think it sounds the best option to insulate while keeping the much loved internal features. Really enjoying this journey... Your knowledge and hard graft is inspiring 😎😍
Put an external wrap around the outside and you will find it it last longer and in the long term it will be cheaper over time
Two things to consider: if you treat the outside, you may need to extend the eaves and roofing; in treating the inside, your window wells will be so deep they'll be like portholes.
We have a stone cottage in SW Scotland we stud framed the cottage and then insulated with Kingspan or its equivalent and then used a layer of space blanket on top then plasterboarded
Your property needs to breath, modern materials are a no no
I live in a 200+year old stone farm house about 3000f^2 same wall thikness as you the peivius people reneevated it. Metle stud frame with insulation and plasterboard. And some areas are dot dabed with insulated plasterboard. We have exsposed stone around the main fire place. Water Underfloor heating on ground floor and heat pump. The house was cement pointed which im not convinced about but every one says lime leeks. We get some condensation and we run a dehumidifier in the laundery room. i want to install a mvhr at some point as the house is now so sealed and could do with some more air flow so consider that. We run the heat pump at a constant temp 24 7 seems to be the most efficient. But if you want a cheep house dont by a big old one.
Personally I would leave the external as is, build the rooms inside with cavity insulation and add glass on certain sections of the walls you like as a feature, like a sealed section looking into the original walls, keep upnthe good work 👏
Thermal mass benefits might be key. If you use any insulation boards on the front or inside like cork or woodfibre youll lose the effectiveness of that. Living in it and just repointing first to see how well temperature is maintained is what i suggest. Insulate the roof and limecrete floor, perhaps underfloor heating and all that jazz first. I found just lime plastering the walls made a huge difference on my thick walled terraced house. I do worry about the internal wall idea creating issues with any wooden lintels above external doors and windows as it moves the dew point. That would have to be addressed. Hope thats helpful.
Once the roof is made good, Double insulate the floors and ceilings, Plaster the bare stone walls,(they were never meant to be exposed) Remove loose/old paint outside and replace with a modern equivalent of what has always been there. We have been constructing and living in these buildings for hundreds of years, they work. Turning your house into a giant carrier bag by sealing up the outside can never be a good idea long term. It will inevitably degrade. Your journey is fascinating! I eagerly await your updates.
Hi, I'm from Germany and lived in serveral old houses, the once that never had problems are the ones made in traditional Matirials, Lime and such. The house need to breath... there is no point in trying to make them airtide... the Windows neues also to be fit for an old house, they need a little of Airflow... but it is so nice to live in an house out of clay and Stone, you can feel the bester air every Day an mold is not an Problem.
Clean the out side and re-paint with a breathable weather proof paint. On the internal have a 50mm air gap, vapour barrier, new insulation and gyprock working round any of the old features that you would like to keep ie the timber beams or the old stone walls. lime wash or plaster the internal stone walls to stop moisture coming through but still give you the feature of the stone walls.
vapour barrier and insulate under the ground floor where possible to stop heat loss through the floor, we fitted under floor heating on top of an old stone floor in a barn conversion and then tiled over it with slate tiles to still give it the rustic barn/farm house feel but with the benefit of not having to walk on cold stone floors. Insulate the loft space to prevent heat loss through the roof as well.
But most of all get the roof completed and then get the heating on and leave it on high. What you will find is that the house has more moisture in it than you realise, so when the heat starts to build up in the house everything will start shrinking back to it's original size and some cracking may appear in the old lath and plaster walls.
I don't have experience of a solid wall house like yours but I did read The Sunday Telegraph Guide To Looking After Your Property by Jeff Howell
In which our hero Jeff answered endless queries from lime mortar solid wall homeowners about damp and waterproofing.
The long and the short of it (which many others here echo and you yourself have said) its about understanding where the dew point is in walls, letting them breathe and keeping the passage of moisture going outwards.
Which as i understand it would be get your log burners going inside and use lime mortar throughout and limewash on the ouside.
Insulate the roof, stud and plaster board the inside. Then get it warmed up. On the outside clean off the flaking and loose parts then repaint with similar material.
Plasterboard does not breath, use Woodwall boards
My grandparents live in a huge house with walls like this. They tried to seal it but it made it worse. Damp got trapped and parts of the ceiling have fallen down. It is because the house is so huge. They need to be heated and lived in. Log burners can end up cheaper. Your choice. Just my experience. You can do what you think is best. (Insulate the floor and celing)
Plant fast growing trees to coppice for firewood - cherry, willow, hazel etc - you will then have a sustainable and free source of logs for your wood burners.
Knowing nothing about stone walled old properties.
I suggest you Focus on making the roof stable and insulated.
Walk round the interior of the property and check for damp moving up the wall.
Then get on ya google and look up every single stone cottage renovation with weather similar.
A good WELL insulated roof can be a great start.
Plus bonus of farm living is you might be able to get loads of advice from other property owners who can tell you what worked what didnt.
But getting the best insulation you can.
The best glazing and doors that are super well fitted can really really help with long term costs.
Also focus on guttering and making sure that you have something like a " french drain" running around the house to leach water away.
I would say your home breathes..
you should be able to get a grant from the Scottish Government to assist with the Insulation and they may well have a consultant that can point you in the right direction
My inlaws had an old stone property in Swaledale, could it be an idea to get some advice from the local builders of that area, especially as a lot of the houses there are solid stone walls. Damp patches always seemed to be a problem though, it seems that no matter what is done moisture seems to find a way through.
Lived in an old farm house. Had had render removed from the outside because it looked nice and then waterproof cement tanking on the inside to “fix” the resulting damp….it didn’t work. Imho id focus efforts on the outside of the building wet walls will never be good insulation no matter what you manage to do inside. The outside is also easier to get consistent insulation.
Not sure about what your heating system is going to be. If you’re considering a heat pump your house needs to be well insulated to get the benefit of it so something else you need to consider.
I would be getting the house fully wind and water tight. If you ain’t doing any structural work adding French doors etc
I would get roof completely finished/renewed. No point doing all the work and the roof leaks and causes damage inside.
If it’s wooden floors on ground level. Lift the floors boards and insulate in between joists.
Get a log burner fitted and this will dry the house out while working in it plus great addition to heat the house once finished.
Make sure windows and doors are up to scratch. Sealed etc.
I would only insulate the external walls inside the building. If space ain’t an issue I would frame it. If it is get it lime plastered
I try to hock up with Charlie DIY, he is on youtube seems to have a old house like yours. But some I recommend to you is insulate your floors, we been though the same with a 1930 house.
If you were in a colder climate, the standard efficiency recommendation would be full external insulation, as well as probably redoing the floors, insulating the ceilings, and installing double pane windows. Unfortunately, external insulation covers up the beautiful exterior. And because your area gets cold but not super cold, you have some flexibility.
If I remember well, the roof is 70% of your insulation, the floor 90% of the feeling, so I'd think the French drain, floorinsulation, floorheating, well insulated roof and preserve the walls with breathable materials at least for now.
A stonemasonery stove, where you do one or two burns per 24hrs and heat a mass of stone/cobb, or concrete that radiates the rest of the day works fantastic. Even if the house is not insulated well enough for it to work with a heatpump or such, it can work toghether I think, although that's not from personal experience.. Anyone?
For windows, a budget solution can be to put an extra window before a single glased and/or use thick shutters that close well. Expensive glasing is better of course, but still, shutters work well.
And think about where you need it to be toasty, where it needs to be comfy and where you need it just to be not mouldy;)) With a good heating and ventilation design.
I can't wait to see what you make of it and what the result of the insulation will be, whatever you choose, because there is many roads that lead to Rome of course..
How do you plan to heat the house? This might also affect your decision here. Underfloor ground source heat pump is an option but might alter your approach to insulation.
Get the drainage, gutters, downspouts, and run off sorted as well...or you will never get that house dried out. :). Good luck
Maybe talk to people in your area that have similar types of houses as having lived in Dumfries and Galloway it rains!! A lot!! Best of luck love following this journey 😊
Option 2 is the best long term solution and most common. Exterior work never lasts
A have had exsternal wall insulation and rendor done on my house yeah exspensive. But christ night and day heating and holding heat. Think there grants available for it aswell in some area’s worth looking into. But best descission a ever made on my house took a little while for place to fully dry out but once it did gas bill hafed as was able to leave it on a low setting. Probs be best solution for use guys in the long run
I see a few new builds now using multi-foil insulation, seems to be pretty easy for roofs before tiles are put on. But can also be used on walls and floors. and i believe can be used externally too. Also if sealed correctly will be a vapour barrier just need an air gap on both sides, and can cut down on space taken when using pir. for example. Speak to the manufactures i`m sure they would be interested in helping.
I would definitely look for a local expert to come a survey and give you options to consider cost wise as that will probably be what option you can afford. probably be the best well spent 2-3 grand in long term. Plus he/she would give you options for sustainable heating using maybe the land to run piping and panels 🤷♀️ I agree just being lived in will help and with the roof done be great if you can keep some of the features 😊
Dont do EWI, we lived in an council house with mo;d. The external walls were all covered in ewi, which once completed does not let the house breath, our mold just got worse to the point we moved from the house. For your style of property i would seriously recommend jet washing the outer wall and regrout them to let it breath. also fit the best extractor fan where you will shower/bath and also cook
We have moved from a log home with lots of exposed/unique wall and ceiling features that we found beautiful to an 'average' house with full interior framing and drywall, which I'm aware isn't relevant on the insulation front, but wanted to say that we MAJORLY underestimated our feelings about interior appearance. We do have regrets about letting go of that house ~to save a little money and have less house to clean~ and find our current one so bleh and boring, if I was in the position of putting a ton of work into a house and planning to live there for a long time, I would definitely want to give more weight to our appearance preferences even though they seem a bit vain in the budget/efficiency/etc conversation. Edited to add: while I do personally love your interior features and would choose to keep it for myself, absolutely not trying to sway the decision in that way!! Just emphasizing not to throw what you love and makes home feel great to you (whether it's interior features, exterior features, clean and tidy plastered walls, etc) under the bus for a slight practical benefit :)
We have recently finished our property, a few videos on our channel. You must remove all cement materials from the walls and use breathable material on outside walls, we used traditional lime and later wood wall boards with lime inside, fully breathable now and noticeably warmer. Get your place water tight first by fixing any roof repairs. Heritage website is very good for info.
Lots of good comments here (and a couple of dodgy ones - please, please, please don't tank it!). Some random thoughts from me, from a rubble-stone cottage in the Highlands...
You have a couple of places where the ground level is a bit high and some where the outside slabs are causing splash-back up the walls. It would be good to sort these out.
My house is a poorer build than yours and we are in a similar dilemma to you. Paralysis by analysis has probably been a good thing, as the building actually works well as intended. Friends have a similar property to mine with internal insulation and it constantly has very high humidity. Air flow is key and in our case we have an oil Rayburn in the kitchen and a woodburner in the lounge, which draw huge amounts of air through and out of the building. Remember, though, that in Scotland our summers are pretty damp and the heating will be off, so in our house that is when internal humidity reaches its highest and the doors start to swell. If you take the internal insulation approach, you might need to consider a whole-house ventilation system of some sort.
The only room that I have insulated was the external bathroom wall, where the bathroom humidity need extra handling (even with an extractor fan) - that has actually been a good option...one short piece of internal insulation won't compromise the building's integrity.
All the EWI houses around here have cheaped-out on the roof-line, so the houses look daft, with the gutters on top of the new external insulation. I worry that when these clog and overflow (as they will at some point), that water is going down the back of the insulation. Getting the new roof line right would be an added cost on top of your EWI estimate.
Sister-in-law has a very similar building to yours which has just been completely renovated with internal PIR/plasterboard lining. It is beautiful, warm and works well. It goes against all my traditionalist lime-fanatic principles, but I have to confess it is now a really nice house and doesn't seem to have any problems.
When insulating the outside you need to remember that will add between 100mm to 150mm on the outside. Will the roof tiles be overlapping the the insulating if not the roof will need extended past the insulating. Personally I would go with a vapour barrier on the inside with insulation on a stud wall. I am a joiner