This is the perfect use-case for IR heating! Heat the people/stuff not the air!

If I were doing such a renovation here is what I’d look at:

• Can you carefully remove the ancient stone floor slabs, insulate, fit UFH, then re-lay the slabs? This’d give you a thermal mass that would gently radiate heat and allow the aforementioned IR heaters to apply quickly-reacting heat as needed.
• Think about how you divide the space up. Small, cosy bedrooms, and separate snug living room, together with huge open-concept living-dining-kitchen space is what I’d go for.
• Realise that this isn’t a “sound financial decision” you need a sense of humour where big bills for simple things are concerned.

 

This is the perfect use-case for IR heating! Heat the people/stuff not the air!

If I were doing such a renovation here is what I’d look at:

• Can you carefully remove the ancient stone floor slabs, insulate, fit UFH, then re-lay the slabs? This’d give you a thermal mass that would gently radiate heat and allow the aforementioned IR heaters to apply quickly reacting heat as needed.
• Think about how you divide the space up. Small, cosy bedrooms, and separate snug living room, together with huge open-concept living-dining-kitchen space is what I’d go for.
• Realise that this isn’t a “sound financial decision” you need a sense of humour where big bills for simple things are concerned.

I'll admit I hadn't thought of IR heating. Does it really work as well as they say? Underfloor heating might be a possibility, no idea on the possibility of pulling up the stones and installing it. My original rough floorplan sketch was this:

So quite similar to what you suggested, with the exception of a large open master bedroom. I made that plan before we saw the church - in reality we'd probably flip it. The "left" windows are broken/missing and so that wall would lend itself to splitting into two floors. We don't really need or want two floors though, but keeping it large and open and heating all that air is what worries us.

One pleasant surprise from seeing it in person - the bell tower (top-left) is really large, and has two upper floors which would be absolutely perfect for a study/ready room with incredible views over the valley.

I can't even begin to imagine what the total cost would be, I have a friendly neighbour who is an architect and who deals with similar projects, I'm looking forward to him getting back from holiday so I can pick his brain on numbers.

 

As someone who has restored an ancient stone building I can attest they can be made very comfortable the key being really good insulation but you also have to work to the restrictions and needs of the building as well so ventilation is needed you cannot go for a passive house , well maybe you could ie build a house within the church so to speak! My house was built for human habitation initially of course so we have low ceilings downstairs. The upstairs spaces were used as hay and apple storage, other parts which make up our living accomodation were actually used to house animals.
A word of warning to undertake a renovation like that if you are doing it yourself becomes very very draining and can take years and years. We spent 4 yrs doing ours, 1 yr of the basics like roof, electrics and plumbing by artisans, 1 year part time starting to finish a house that was handed over with the plasterboard up but not taped and skimmed and other features dans san jus as they say ie no treatment to the exposed stonework and then 2yrs after we moved in permanently. Do not assume anything at all re planning or access to utilities or costs or what you can achieve in design. I would try to seek our some specialist advice from people or companies who have done this before.
whilst space is very attractive especially to us used to living in what are essentially very small pokey houses for the majority of us too much can be very hard to convert into pleasurable living accommodation and @Stinsy suggestion of small discrete spaces is a good one.
I wish you well but I can guarantee there will be a lot of pain involved as well as pleasure but only you can say if the balance is right for you. I have friends who have been working on a columbage property here (wooden construction of oak beam and wattle and daub your architypal tudor style prpoerty) a mush easier construction to deal with in many ways over stone and they are still not finished 24yrs later. They have worked every summer for at least 16 of those years plus easter etc. He reroofed it over 5 yrs!
Thick stone walls make things like putting in doors and windows in different places very difficult if not impossible expensive in time and therefore cost if employing someone to do it. Running plumbing and electrics through one space to another usually means very long drill bits and much longer installation times. One tip it seems in general wood is still used for the plasterboard supports, here in France it is metal I would really recommend this it is quick but more importantly will not warp or rot and can hold the insulation!
bonne chance

 

My concern would be the prime selling point of old churches is the height. Traditional heating would just pump heat into the eaves so as Stinsy said I'd be looking into IR heaters for sure.
Under flags heading would be great but you'd likely need to invest in a MHR+V System to pump some of that stored heat back into the living space. It would also help ventilation and stop mould (solid walled old properties suddenly made airtight dont generally like it so this would be a real bonus).Bang solar on the roof and a chonky battery in one of the many utility rooms hidden away and you'll be laughing. I'd also look at rainwater recovery as most churches have huge roofs and given no mains water it could be of some real benefit (although I imagine you'd be getting mains water as part of the rebuild)

 

Two thoughts - neighbours of an aunt bought an old pumping house in the lakes. C.1900 Shaped and constructed not unlike a church. In the one large space that was the building they put Mezzanines (bedrooms/bathrooms) either side of a central full height living section.

second - a scout hut near us completely renovated their church hall style building - lots of internal insulation and IR heaters on the (pitched) ceiling. Works well.

 

second - a scout hut near us completely renovated their church hall style building - lots of internal insulation and IR heaters on the (pitched) ceiling. Works well.

That is promising, I really love the idea of massive open spaces on either end, surrounding a central "boxed-in" section with bedrooms and a bathroom. Maybe a loft on top? So if the IR heating panels could properly keep us (and our pets) warm, that might not be that bad. Do IR panels help with combatting damp at all? Not sure how we'd get around the ventilation issue...

 

I know of one church built in a classic style with a vast very high open space that underwent a deep retrofit as a church. The solution was under floor heating and it works really well. One would think the heat would be conducted up to the ceiling but because the temperature is even across the floor it locks in a layer above the floor. The only snag was that assistance dogs found the floor a bit toasty to lie on and became rather smelly. Dog mats solved that one.

The 'get out of jail' card for any unexpected air movement shifting heat would be slow ceiling fans to send the warmed air back down again. There was no need in this building to do this. Very comfortable draught free space.

If you want to take it slowly then your first urgent priority is to make the building water tight. Your costs will run away if you allow water to start or continue to get in to do water damage. Overall cost it for what you can see needs doing and then double it to allow for what is unseen.

I would challenge your intention to live only on one level. Why waste the space you have from height to essentially put a bungalow inside a church? I think any good architect would be of the same view and suggest much more satisfying development of the volume on offer with a mixture of high open spaces and cosy snug ones. You may well need to live mainly on an upper level if you want to be able to look out of the windows.

You need to find out if there is wildlife in the building. Building work becomes a nightmare if you have for example bats.

Personally I would go for a building inside a building with one area opening out to make the inside of the church and space a feature. A mixture of the easy to heat and live in and the dramatic but potentially hard to heat spaces. To connect it all up I would use lots of glass to link visually some of the cosy spaces to the big space. Services could be on the outer skin of the inner shell and if you had the space you could keep them accessible with a good gap between outer and inner walls or use the gap as storage areas.

Tall windows are a gift, put in secondary glazing and let the upper floor stop short of the window recess and you will have floor to ceiling light for the upper floor and the light can still get down to the ground floor.

 

You need to find out if there is wildlife in the building. Buliding work becomes a nightmare if you have for example bats.

We saw no evidence of wildlife inside, the condition isn't actually that bad considering:

 

Damp is an important issue to solve in older buildings however it isn’t difficult!

1) Make sure there aren’t any leaks letting water in. Roof/windows/guttering are your main culprits.

2) Ventilation. You need to shift a lot of air. This used to mean “passive” vents but nowadays MVHR is mature technology. Take moist air from the bathrooms/kitchen and deliver warm/dry air back to the living areas. Make sure to “go large” on the volume of air shifted and install the heating loop on the incoming air.

 

I'm not sure you know much about old buildings

It's a solid wall church in Wales, which means it likely suffers from wind-blown rain on one, possibly two faces, that will cause moisture to drive into the stone work. You would need to change the external material properties of the building (i.e. cladding and vapour barrier) to defeat that. This is hugely expensive and often rejected by local planning.

For a MVHR to function correctly in a church building it would require significant dividing of the interior of the church. Something which typically you wouldn't do to preserve the character. You'd end up with a ducting system suspended from your vaulted ceiling! Noice!

 

I can't answer your question, but having stayed in a few chapels converted to holiday accomodation I have to say that all of them lost their architectural unity and much of their appeal once double glazing and a first floor are installed, even if that first floor comprises a mezzanine or what used to be called a gallery in English. Full first floors invariably cut across the tall windows, a problem for which I have never seen an elegant solution.

From the outside they looked fine, but internally the addition of modern adaptations changed character to caricature, so get some good visualisations of the planned work before committing any money to ensure you will not be disappointed with the result.

 

We had a gallery in our main living room. Despite four fancoils on the ASHP I wouldn't describe it as cosy unless the multi-fuel stove was lit. Perhaps if the flow temp was upped from 30 odd degrees C. That was a railway building conversion though.

 

Oddly enough I've just been reading about heat pumps in old buildings and there are a couple of churches as case studies.

Heat Pumps in Historic Buildings | Historic England

Ten case studies reviewing the performance of air source heat pump (ASHP) technology in homes, offices, shops and two small churches across England.

historicengland.org.uk

 

One big plus is the church isn't listed (I guess ~200 years isn't enough time to make it 'historic'?) so theoretically getting planning permission to make modifications wouldn't be as difficult as it otherwise could be.

Chapels and churches are dime a dozen in Welsh villages and towns from start of the industrial revolution! Many, many are now homes, 3 of the 5 in my parish alone!

That doesn't necessarily mean you have lots of scope for modifying the exterior, but that depends on many factors. Perhaps worth a look around locally.

 

Having spent far too much time in far too many old churches.... Some observations for what they're worth. Thick stone walls can maintain temperature pretty well with huge thermal inertia. If you let it get cold, it's hard to warm up. I really like Stinsy's idea of constant low level heat, heat pump powered UFW, especially if you can have plenty of solar, makes a lot of sense. Then additional heat with IR panels as you need it.

Seal it up.... it's almost the exact opposite of a passivehaus - everything leaks everywhere. You will need to properly stop up the draughts as much as possible then introduce controlled ventilation. A heat recovery ventilation system is a must.

Fix all the problems outside. Lots of these old buildings have penetrating damp issues from neglect. Poor grounds maintenance, blocked and leaking guttering, usually really simple stuff that gets left for years and before you know it everthing's wet inside. These problems often start long before the church is declared redundant as the congregation ages and, usually literally, dies off. It can make the problems look much more serious than they are.

Some of the rooms you might build can be really well insulated and almost treated as passive structures within the larger building, reducing the need for heat input.

There's no getting away from heat rising and the temperature differential in a tall space like that can be considerable. Air-circulation that pulls warm air from on high can help. That's something worth bearing in mind when positining rooms. I've seen conversions where the upstairs bedrooms are routinely too warm. Nothing you can't fix with appropriate ventilation and insulation but it's better not to create the problems to start with.

 

I once saw the simple solution of ceiling to floor pipes to suck the heat back down again, lol.

 

You might want to be cheeky - knock on some doors and take a tour around of a number of other conversions - learn from others' successes and failures...

 

Green Building Magazine has lots of case studies of new builds and eco-refits of all sorts of buildings.

The two volume Green Building Bible is also one of my go-to books.

More here in sidebars to this article:

http://greenbuilding.co.uk/british-homes-among-the-worst-in-europe-for-green-living/

 

My house is granite with walls close to a metre thick generally double layer with a rock and soil infill. Nice and cool in summer and retains the thermal solar gain from the windows in the winter and keeps its temperature pretty well, once cold a few hours of the log burners tends to be enough to warm it up. We have no internal damp issues at all despite the horror to most of you here I am sure of not having lifted the floor in 1 half of the house which is still original tomettes laid on earth and also granite slabs but the house stands on extremely well draining soil. The dining and living room have modern concrete.
So how the walls react to wind driven rain will to some degree depend on the type of stone and also the ground on which the place is built. We do have 1 issue we have never been able to master and that is a leak from one of the chimneys despite Numerous attempts at repointing and re flashing. The answer used by locals is to slate clad the chimney something we may get organised one day but it looks very moche……
Lots of interesting ideas here quite different in many ways to how other Europeans see the conversion of such buildings. Our village church built in the same way as my house but it has a dreadful damp issue some is condensation other is penetrating the roof is in ok condition having been redone about 20yrs ago. This church is in a much better condition But ours dates back to the 1200’s. Hope the OP,keeps us updated

 

My family has a 200 year old slate hung farmhouse in a deep valley on the southern edge of Dartmoor. Once you have seen the driving rain there it is clear why the house is slate hung. The old builders knew what they were doing and why. Snug and dry inside the house.

 

It still isn’t cheap but there are aerogel based insulation products on the market now and I expect they will become more widely available / accessible with the passage of time.

These can be a fraction of the thickness of more traditional products and just as effective.

If you’re looking to sympathetically insulate an old building without cloaking everything in 300mm of insulation they are worth a look.

10mm of this stuff significantly outperforms 120mm thick kingspan style insulation.

It is however currently 4x the price of 120mm kingspan.

I used it on the internal wall of my front bay window where it was impractical to fit standard insulation and it is absolutely brilliant!

 

It still isn’t cheap but there are aerogel based insulation products on the market now and I expect they will become more widely available / accessible with the passage of time.

These can be a fraction of the thickness of more traditional products and just as effective.

If you’re looking to sympathetically insulate an old building without cloaking everything in 300mm of insulation they are worth a look.

10mm of this stuff significantly outperforms 120mm thick kingspan style insulation.

It is however currently 4x the price of 120mm kingspan.

I used it on the internal wall of my front bay window where it was impractical to fit standard insulation and it is absolutely brilliant!

Five points:

1) If the extra thickness to get the same level of performance is not an issue then there are much cheaper alternatives for breathable internal insulation.
2) Internal insulation is going to make a solid wall colder so it will move where the dew point is in the wall. Without careful consideration of the building physics this can have long term serious consequences like rotting joist ends if they are embedded in the wall. (In a modern build you would put the joists on hangers otherwise they are potential cold bridges as well.)
3) Would one want to sacrifice the look of the original lime plaster walls.
4) Fire safety of some of the wall cladding products.
5) The breathability of the internal insulation needs to be in the right ratio to that of the external face of the wall. 10 (internal) to 1 (external) ratio for the Sd value is considered good practice to prevent structural damage due to diffusion of water vapour. The porosity of the external stone will affect the Sd value. The Sd value is the equivalent air gap in metres for the material forming the airtight layer on the face of a wall. Note: A rendered brick wall is often a sign that bricks have become porous with age or were poor quality and rendering has been needed to reduce damp penetration into the wall.

 

Surely there must be a clear microporous coating that you can apply to the sandstone to help shed rain but let the stone breathe? And obviously you need to make sure the pointing or whatever is in top order to prevent water coming through the stone work. And given it is Wales the roof water is probably fit for drinking, you just need a 15 m3 storage tank! No water bills. That is common in NZ and during droughts they get it delivered by tanker. UFH would be the way to go, the floor doesn’t appear special and if it is just bricks of some sort get them lifted to reuse. A floor like that can be heated overnight on cheap tariff electricity you’ll need to work out the heat loss but a pair of 11 kW heat pumps working in tandem might give you a COP of 4 or better. UFH seems to be best if the pipe density is high, that is about 150mm centres. Make sure there is insulation inside of the base of the walls and run the hot pipes around the outside working inwards. The temperature difference between out and back needs to be about 4 degrees. To achieve that you will want to push a lot of water round the system, 3 or 4 m3 an hour with the flow temperature of just 35 degrees. Two heat pumps ASHP would work well handling such a flow rate.

 

Great video on insulating stone walls here:

Engine Shed advice on how to insulate stone walls

Find out from the Engine Shed how to insulate stone walls to improve energy efficiency, including details of the five main wall insulation options.

www.engineshed.scot

 

Can't you just get a big coat?

 

If you did decide to go for some internal thermal insulation, then you might consider lime hemp...

 

A lot depends on if the lime plaster internal wall finish (assuming it is lime and it should be for a solid wall) is on the 'hard' or there is wood lath and plaster build-up and an air gap as a consequence.

Sometimes it is better to leave the air gap and apply an insulation product on the inner most surface and other times blow in an insulation fill. Whatever the internal insulation chosen for a solid wall is it needs to be vapour permeable. That means no to any closed cell insulation technique. At the moment we don't know if the church internal plaster is on laths or not.

Classic solid wall construction must be able to breathe . Classic mistakes are the use of cement (brown/grey) instead of lime mortar (more creamy in colour) for pointing and internal paints and finishes like vinyl wallpaper or tiles that form vapour barriers. Cement can damage stone work and lime mortar allows slight movement in the walls without generating cracks.

Internal insulation of the original structure is achievable but as others have noted it is important to ensure the shift in the dew point in the wall and the normal wetting depth from the outside is not going to cause problems because the wall runs colder with less heat transfer or more extreme weather increases the wetting depth. Good practice would run a computer model simulation to ensure the prospective treatment is not likely to cause problems and can cope as climate changes weather events. This needs somebody fully up to speed with building physics and the right software and most architects would sub-contract to a specialist for this.

 

I’ve just had a read through this thread and there is frankly some terrible advice!

“Just bung some insulation inside the stone walls” is a recipe for disaster damp wise. Sure you can build insulated structures inside the church for bedrooms etc. but you need to ensure the dew point remains inside the stone.

Also the thought of modifying the outside of the church is silly. You might as well buy a cookie-cutter new-build. And you wouldn’t get planning consent anyway!

The principles of my original post remain:

1) Utilise the thermal mass.

2) Have a fast-reacting source of heat in addition to the thermal mass heating.

3) Ventilation, ventilation, ventilation (with heat recovery).

 

Would air to air heat pump work, do they not dehumidify at the same time?

 

Hmmm, we may have hit a bit of a wall on the mortgage front... I didn't realise it would be quite as difficult to secure a mortgage on such a "cheap" property, but apparently only a few banks actually do renovation mortgages? According to some forums almost none of the high street banks will do a mortgage for a derelict property. This is unfortunate, as our list of possible banks is already quite small (I have a good salary and excellent UK credit, but I get paid in US Dollars, which is an instant "no" for most financial institutions...). I'm not sure anyone exists in the overlap between "will do a renovation mortgage for a derelict property" and "will give a mortgage to someone not paid in GBP".

I did contact the Ecology Building Society, and they said they might be able to help, but they are currently focusing on properties that are "aiming for Passivhaus or EPC B (SAP rating 85+) or above" - I am doubtful whether that is achievable with a reasonable budget on an old stone church in Wales...

edit: I should note that we would absolutely be aiming for the most efficient home possible, I'm just not sure what is attainable for this sort of property.

 

Have you tried the ethical bank Triodos in Bristol? Full disclosure I once met the chief operating officer who stepped down from a very high powered finance position to take the position with Triodos because he wanted to a) see his family growing up and b) was sick of the unethical but legal practices of the industry he was in. He was a breath of fresh air to talk to as a man of principle.

Bristol seems to be the centre of alternative finance for green eco-minded activity. Might be an idea to pitch wider than just the restoration of the church but feature the inward investment and employment activity it brings to the local economy. A good surveyor's report on the feasibility of reaching EPA B could swing it for you.

Would it be better to describe the property as disused rather than derelict? From the photo it does not look that far gone. Derelict is a 'red flag' word in the world of property. Lack of water supply would put most off. If the church yard has a burial ground you need to check if it is still active and there may be a restrictive covenant that you have to allow access in the sale of the building. Also try and find out if there are any burials inside the church or it is the site of a former church. If you encounter remains of former building or folk it will incur a lot of extra cost and potentially delay. But you can derisk delay by doing a slow sequential phased project instead of working to a hard deadline for a completion date. Once you are clear of any groundworks the risks reduce signifcantly.

Hard to tell from the single photo but Passivhaus is expensive anyway and practically confined to high quality new build, however EPC B could be possible but I do think it would be tiles/slates off to do the roof insulation and how to do the join between the internal wall insulation and the roof insulation could be quite complex to get working well. Final costs depend much on the condition of the stone work and just how thick the solid walls are. The thicker the better as it gives you more flexibilty for the depth of the wetting zone coming in and the dew point going out with a nice distance between them and excellent thermal inertia. Looking at the depth of the window recesses it looks as if you have a good chance of success. Heartbreak restoration is usually with thin solid walls where a cottage was a cheap jerry build construction from the word go for some poor ag lab. Despite being historic they did know how to build then and a well constructed and maintained historic building should not be damp. Most problems with historic building arise from a lack of maintenance or a shift in the environment like a water table rising or soil levels around a building building up.. The first place you look is the roof as it is the weakest part of any building and the first to wear out.

An example of a problem from change of use is here in the link below: where you can see what appears to be a line of damp that tracks the disused fireplace flue behind it on the side wall. The flue had been cut into the wall not build up. In original use the fireplace in use would have kept the thinner wall dry but out of use the wall is too thin and the flue cold. Result damp but the thicker walls either side are OK as is the front of the building built with dressed blocks instead of the side walls which are rubble (often cheaper poorer quality stone from higher up in the quarry). The alternative is a defective chimney top which is a very common cause of damp and usually not that difficult to fix. However the damp comes so far down without spreading that I think the thinness of the wall (shown on plan) is the main factor.

Check out this 4 bedroom end of terrace house for sale on Rightmove

4 bedroom end of terrace house for sale in Lower Littleworth, Amberley, GL5 for £725,000. Marketed by Peter Joy Estate Agents, Nailsworth

www.rightmove.co.uk

You are practically a potential self builder so why not get along to the National Self Build and Renovation Centre at Swindon. It is just of J16 of the M4 and signposted. They cover finance for projects as well as all the building techniques. They also run courses some on line. Pre-book to visit and tickets are free. A day there will be very informative. They, at the advice sessions, can help with the issues around provision of utilities which can incur significant costs to be fully connected. Bear in mind you will need a water supply to undertake building work.

NSBRC - Home

www.nsbrc.co.uk

Finding a site is harder than getting finance and you have got over the first and most difficult hurdle. Keep going, the project has huge potential to produce a wonderful home.

 

I should note that we would absolutely be aiming for the most efficient home possible,

As awesome as the project sounds, going for an old church seems to be on the opposite end of this. Or do you mean you're going to try and make the church as efficient as it can be?

Either way it sounds like headache after head ache and obviously it depends how much you want it.

 

Oh, I recognise the inconsistency... 😅 It is an attempt to marry up my desire to retire in an uber-efficient bespoke home with my (medieval historian) wife's dream of living in an old church...

 

Update: Sooooo many conversations with my wife, our friendly architect neighbour, a building inspector (who hasn't inspected the church, we just chatted over a pint), and a few others over the past week... We came to the conclusion that while the church is perfect for us, the location is good but not perfect (perfect would be a good view, and a pub and shop within walking distance. This place has an incredible view [especially from the tower!] and a pub 1.1 miles away, but no shop), and the timing is not ideal. Two years from now we'll have our cars paid off and be in a much better position financially, and four years from now we'll have no debt and have a good chunk of cash saved up to throw at a renovation project immediately. So while we can do it now, and I'm not optimistic we'll find a church quite this perfect for us, it might not be the smart thing to do.

All that being said, a friend suggested we put in a low-ball offer that'll surely be rejected, but who knows? The church has been empty for 10-15 years, maybe they'll just want to get rid of it. So this morning I emailed with a (very) low offer, an amount which we can get the cash for on the (very) off-chance it is accepted. And if it is accepted, we will go from there!

 

That's how we ended up with our current home!

When buying our previous 3-bed semi my wife and I had seen this 5-bed for sale, completely out of our reach and had said to eachother "one day". 2 years later it was still for sale we put in a silly-low offer and it was accepted. I still can't believe we got it so cheap but the owners had moved to Australia and had bought it decades previously for pennies. I guess they wanted rid of the millstone and needed the cash to get their new life going...

 

Good luck! And makes sense!

 

Sounds a good plan! Worst they can say is "no" and then you have the answer. You never know if they might be holding out for "anything higher than 30% of asking!".

 

That would be great, as our offer was 43% of asking...

 

If they wanted top dollar surely they would have ticked off some basics like water etc so it can be mortaged?