Heat loss and retrofit

[BuildPentir]

Hi all

 

Looking to make sense of further heart loss reduction and ASHP installation in a Welsh house with 1m thick stone walls and ancient central heating. 

 

Additionally, if anyone can tell me how to sort out bifold upvc doors, short of scrapping them I would be very grateful...

[MikeSharp01]

Welcome to THE forum for people like us. 

 

34 minutes ago, BuildPentir said:

Looking to make sense of further heart loss reduction and ASHP installation in a Welsh house with 1m thick stone walls and ancient central heating. 

 

People will be along shortly I am confident @Gone West has not dissimilar challenges for one.

[SteamyTea]

Welcome.

 

The wall thickness makes no material difference to how you calculate heat losses.

 

Start by accurately measuring the house, those dimensions will be useful to work out where the biggest losses are from.

[Redbeard]

1 hour ago, BuildPentir said:

Looking to make sense of further heart loss

 

I think it never makes sense. Keep the full one.😉

[Gone West]

14 hours ago, MikeSharp01 said:

Welcome to THE forum for people like us. 

 

 

People will be along shortly I am confident @Gone West has not dissimilar challenges for one.

@BuildPentir Yes I have, and am still researching. I do have some 70s additions which are easier to deal with. I think @Roger440 has similar problems and may also be in Wales. You are not alone!!

[jayc89]

Dry, thick stone walls are typically not that bad insulators, with the majority of heat-loss coming from the floor, roof and a lack of airtightness. 

 

Unfortunately one size doesn't fit all when it comes to insulating older properties and the porosity of the stone will dictate how best to detail the walls; a highly porous stone will require a permeable/hygroscopic finish (hemp plaster, cork, wood fibre etc. inc a permeable paint/wallpaper), whereas a less porous stone might get away with impermeable/hygrophobic materials (PIR, rock wool etc)

[Iceverge]

1. Install mechanical ventilation. Even replacing a bathroom fan with some dMEV for £60 will do. 

 

2. AIRTIGHTNESS. The single biggest and cheapest thing you can do. Get some airtight silicon/foam/tape and go draft hunting. This may include taping the bifolds closed for the winter! Beware, good airtightness without a proper ventilation plan isn't a good idea.

 

3. Some loft roll would help. 

 

 

Edited February 15 by Iceverge

[Roger440]

12 hours ago, jayc89 said:

Dry, thick stone walls are typically not that bad insulators, with the majority of heat-loss coming from the floor, roof and a lack of airtightness. 

 

Unfortunately one size doesn't fit all when it comes to insulating older properties and the porosity of the stone will dictate how best to detail the walls; a highly porous stone will require a permeable/hygroscopic finish (hemp plaster, cork, wood fibre etc. inc a permeable paint/wallpaper), whereas a less porous stone might get away with impermeable/hygrophobic materials (PIR, rock wool etc)

 

Dry stone walls are indeed not terrible. Problem is, most a sdamp or wet as a consequence of inappropiate choices made in the past.

 

Whatever else you problems, if its not dry, thats the first thing to address. OP, you make no mention of this?

 

There are pretty much no circumstances under which PIR or the like is a good idea on such a house with no DPC.

[Roger440]

1 hour ago, Iceverge said:

1. Install mechanical ventilation. Even replacing a bathroom fan with some dMEV for £60 will do. 

 

2. AIRTIGHTNESS. The single biggest and cheapest thing you can do. Get some airtight silicon/foam/tape and go draft hunting. This may include taping the bifolds closed for the winter! Beware, good airtightness without a proper ventilation plan isn't a good idea.

 

3. Some loft roll would help. 

 

 

 

What he said^^^

 

The average welsh stone cottage isnt going to be remotely air tight. Start here.

 

As far as the bifolds are concerned, normally everything is adjustable. However, the problem ive run into 3 times now, is the frame being so far out of true, that no amount of adjustment can sort it. In which case taping them up might be the sensible option.

[Ross Peters]

I saw your forum about BR and retrofitting insulation. This has haunted me for the past year. I have a listed building with planning for dormers. This triggered building control requiring thermal upgrades. To comply would mean covering all the historic beams - the character I bought the building for!. Furthermore planning conservation weren’t receptive to non breathable systems such as PIR or Rockwall which provide better u values than vapour permeable ones and are a lot cheaper!. I looked at regs and thought as a listed building I may be exempt from complying. I emailed the conservation officer for his views and asked that he draft a response that intervention may be detrimental to the historic building. I wanted to insulate for my comfort (uninsulated walls wafer thin weatherboard on timber stud with lathe and plaster, others bare double skin brick, no membrane just naked tiles on rafters to roof) and shared some vp insulated membrane systems and sheep’s wool ideas that he accepted. I did some research - sought advise from specialists and proposed to building control different thermal upgrade systems using hygroscopic breathable insulation including tlx gold, activis silver, wood wool, thermafleece, wood fibre and lime plaster each bespoke to all manor of different construction types added to the building over the past 400 years! I sent the best u values achievable to Building control and carried out the works. £60k later (specialist plasters and insulation don’t come cheap) and the building is functioning well but the conservation officer left and building control won’t sign off based on email communication and notional approved systems and want an exception letter which the new team won’t do. I don’t get my sign off.

[kandgmitchell]

So your BC are ignoring this in Approved Document L1 then?

 

Historic and traditional dwellings
0.10 The energy efficiency of historic and traditional dwellings should be improved only if doing so will not cause long-term deterioration of the building’s fabric or fittings. In particular, this applies to historic and traditional buildings with a vapour permeable construction that both absorbs moisture and readily allows moisture to evaporate. Examples include those built with wattle and daub, cob or stone and constructions using lime render or mortar.

 and:

 

0.12 In determining whether full energy efficiency improvements should be made, the building control body should consider the advice of the local authority’s conservation officer.

 

Which advice presumably is contained within the emails between you and conservation officer at the time of the works. To whose benefit is this sort of pedantic nonsense?