Gas saving from cavity wall insulation?

oldskoo1

Anyone who has had cavity wall insulation installed can they quantify what saving it has made to your gas bill please?

x amount of £'s off your gas bill?

We are moving into a new house soon and were surprised to hear it doesn't have cavity wall insulation despite being only 9 years old. I thought all new-ish builds had this.

I considered posting in the green and ethical forum but people usually discuss cost of install in there and never give a monetary saving.

Obviously the cost is minor but with the stories of damp spots i'm wondering just how much difference it would make to a 9 year, 5 bed, 3 story; if it's worth it as the installer said it would damage the appearance of the house by chipping the corners off the bricks as they drill through the cement.

Yorkie1

I have a 1930's semi with floorboards (draughty). I've been here just over 2 years. In the first year I used 22,000 kWh of gas (that was the really cold winter with -18C). In the second year, having CWI, increased loft insulation & DG installed, I used 17,000.

Can't say how much of that was down to CWI though.

Cardew

It is my understanding that Building Regulations had made it mandatory for all dwelling houses to to have cavity insulation for the past 20 years or so. I had a new house built in 1988 and it was part of the NHBC specification.

A quick Google produced this statement from a council:

Building regulations required all homes built between 1985 and 1990 to have partially insulated cavity walls, and since 1990 all new homes are required to have fully filled cavity walls.

I assume your house does have a certificate from the Builing Regs control department.

Anyway on savings, the Energy Saving Trust have some data

http://www.energysavingtrust.org.uk/In-your-home/Roofs-floors-walls-and-windows/Cavity-wall-insulation

That states £135pa saving for a 3 bed semi with gas CH

Obviously the type of property will be a huge factor - a mid-terrace house will save a lot less than a detached dwelling; also the type of heating is a factor.

snowcat53

The year following CWI, our gas consumption (not bills) was down 9%. This is for a detached house. Not sure how of this down to CWI but our winter the year after installation was very cold, so the true figure could be even higher.

No problems with damp etc either.

oldskoo1

Thanks all

I was so surprised to learn it didn't have cavity insulation. It was built in 2003. I might have to clarify with a surveyor. Perhaps it only has part insulation and they just fill the rest of the cavity.

Irie87

Recently had CWI and Loft insulation done on our upstairs Maisonette. I will be intrigued to see how much our consumption drops and the best thing of all was that it was totally free!

macman

If the property is only 9 years old then can you not invoke the 10 year NHBC warranty to get it installed for free-as it should have been anyway?

WestonDave

I wonder if the sort of solid slab insulation they use on newer properties is referred to as something different than cavity wall insulation. Some more recent properties I've seen being built have been a timber interior shell, insulation covering and then brick (or block and render) exterior. I can see that being effectively cavity wall insulated but called something else.

(Might be worth having a look on your council website to see if the planning documents are available online or asking at the council for a copy if they are only paper copies - those should give details of the planned construction methods etc)

Cardew

WestonDave wrote: »

I wonder if the sort of solid slab insulation they use on newer properties is referred to as something different than cavity wall insulation. Some more recent properties I've seen being built have been a timber interior shell, insulation covering and then brick (or block and render) exterior. I can see that being effectively cavity wall insulated but called something else.

(Might be worth having a look on your council website to see if the planning documents are available online or asking at the council for a copy if they are only paper copies - those should give details of the planned construction methods etc)

That is Kingspan(or similar) and I think is used in most new properties these days.

It is used also on the more traditional buildings of Brick outer and block inner.

meggsy

We had a new porch built about 10 years ago and block insulation was used then. House doesn't have CWI though!

JJ_Egan

Difficult to quantify any saving due to price increases after cavity and loft insulation .
But i can say bedrooms are much hotter winter and summer in fact holding the heat to much . Duvets no longer required most of the year .


jje