Old stone cottage/solid wall heat retention?

aquat26

I've recently purchased a stone cottage built around 1860 with solid walls that are about 1/2 a meter thick. We are currently having quotes done for the installation of central heating and internal wall insulation (various types of heating systems and insulation are being considered). One thing that certain builders keep saying, is that there is no need for internal solid wall insulation. They say that once these walls heat up they retain heat quite well.

I would like to hear your opinions on this.

Thanks.

Ebe_Scrooge

That's pretty much true. I used to live in a 400 year old house with damn great thick walls as you describe.

In summer it's lovely as the inside of the house stays nice and cool. In winter we found that it takes ages to get the place warmed up, but then it stays warm with the heating just "ticking over", so to speak. If you think about it, the walls are acting like blooming great storage heaters.

If the walls are thick enough, then not much heat actually manages to find its way right through the wall and to the outside.

What it is worth doing on older places is spending money on insulating the loft, and on draft exclusion. You'll generally find lots of draughts in older properties.

The other consideration is double glazing. Again you'll be surprised how much heat is lost through old windows. The problem being, it ain't cheap, and if the property is a listed building ( as ours was ), then you're very limited as to what you're allowed to do in terms of replacing windows. But worth looking into.

Johnandabby

The thick stone walls provide high thermal mass, which is why it takes ages to heat up in the winter but also why it also stays cool in the summer. The 'danger' with installing internal insulation is that you reduce the thermal mass - it takes less time to heat up, but also gets hotter in the summer. Personally, I would be happy to spend more money heating in the winter to stay cool in the summer!


You will still lose heat out through the walls in the winter - it's a two way storage heater.

Gloomendoom

As post 2. Our house over 300 years old and it is cosy in winter and cool in the summer.

aquat26

So if I can expand the topic a little, what type of central heating system would you recommend if we don't install solid wall insulation? We currently have old night storage heaters which MUST go! We are having new doors, windows, loft insulation and underfloor insulation installed. Biomass, ground source, solar pv aren't options, We aren't on gas mains. So the obvious contenders are oil or air source heat pumps. I've read that air source shouldn't be considered without solid wall insulation.

Once again, would like to hear your opinions. Thanks for replies thus far.

Ebe_Scrooge

From what you've described I would say conventional oil is your best bet. Air- or Ground-source heat pumps would , I think, not really be suited to that type of property. If you can't have bio-mass or wood pellet for whatever reason, then you're limited to oil or LPG really. Of these, oil is the better option.

If you do go for oil, then install the biggest tank you can - or even 2 ( you'd need to check what the regulations are about how much you're allowed to store on a domestic premises ). But the idea being, you can buy in one go enough oil to last a year. So you can watch the prices, and choose when to buy ( usually during the summer when demand is lower ). You then won't be stuck with having to buy in winter when the prices inevitably increase.

I'm on oil, and have been seriously thinking about getting a second tank for this very reason.

turboace

Ebe_Scrooge wrote: »

That's pretty much true. I used to live in a 400 year old house with damn great thick walls as you describe.

In summer it's lovely as the inside of the house stays nice and cool. In winter we found that it takes ages to get the place warmed up, but then it stays warm with the heating just "ticking over", so to speak. If you think about it, the walls are acting like blooming great storage heaters.

If the walls are thick enough, then not much heat actually manages to find its way right through the wall and to the outside.

What it is worth doing on older places is spending money on insulating the loft, and on draft exclusion. You'll generally find lots of draughts in older properties.

The other consideration is double glazing. Again you'll be surprised how much heat is lost through old windows. The problem being, it ain't cheap, and if the property is a listed building ( as ours was ), then you're very limited as to what you're allowed to do in terms of replacing windows. But worth looking into.

Does anyone know how the cost of heating a stone cottage such as this would compare with houses built in the 1980s and 1990s, assuming similar sizeand both with double glazing?

Gloomendoom

No double glazing but we spend about £1000 a year on gas. No idea how this would compare with a modern house of similar size.

doningtonphil

hello. wee bought a stone walled single storey cottage in Dec 2013. In doing our research for grants/insulation requirements etc, the indications are that solid stone walls are considered the 'worst' walls to have regarding energy performance.


When we did the bathroom (2m x 2m with one external wall 25% of which is a window) we stripped the old plasterboard as it was soaking with condensation- the room was extremely cold. We put 40mm celotex between the batons and then new plasterboard. It has made a real difference.


On the celotex.co.uk website (which you need to register for) you can use a U value calculator to calculate how much insulation you need to meet the required efficiency standard. When i calculated, it stated we needed 60mm insulation to meet the required rating