Building Regs relating to wall insulation change of use

[Thenewsusieq]

Hi all,

Can someone give me a bit of help please? I'm looking to buy a disused chapel to convert to domestic use. It's built of red brick in Flemish Bond with original hardwood arched sash windows and doors. Has a slate dpc, no rising damp. I'm confused by the Regs - will I HAVE to insulate walls? why?? my current place is also FB, no cavity, perfectly warm....

The problems are these - there are a large number of arched architraves to think about which don't have sufficient rebate to accommodate materials such as Celotex/battens etc; and I loathe square plasterboarded rooms in period buildings....it never looks right. If I do have to insulate (and it must be internal, the outside can't be rendered) are there any alternatives which achieve the goals of working with the architraves and not ending up with squared off boxes? Btw how are U values arrived at?

One further question - will I also be forced to double glaze? And if so will BC accept removable secondary glazing?

All help much appreciated!

 

[freddiemercurystwin]

In cases like this Building Control can be sympathetic to the existing features, its difficult to say just how accommodating they will be here as they will be looked at on an individual basis. There are ways of compensating elsewhere by adding extra roof insulation for example. If possible it would be worth trying to arrange a meeting at the property with the actual Building Control officer who deals with your area and is likely to be the one signing off the work, its important to work with them and not go in all guns blazing.

 

[Thenewsusieq]

Thanks FMB for that.....very interesting. I am planning to create a roof space which would be very well insulated and also to insulate the floors with thermal board before putting down electric UHF throughout.....so would all this help to achieve required U values......? Questions beget questions....are U values of a BUILDING then, or of individual aspects such as walls, windows, doors, roof? Sorry to be asking questions that to many must seem very stupid!

 

[freddiemercurystwin]

A wall or a floor, window or roof for example has a U Value, which is a measure of how much heat can be lost through it (so the lower the better).

Individual elements such as bricks or plasterboard or insulation have a Thermal Resistance, which is the measure of heat lost through it.

When the thermal resistance of each element that makes up an element eg a wall is fed into a calculation, you can work out the U Value of that element. So by changing a particular type of block with another or changing the thickness of the insulation for instance will have an effect on your U Value.

 

[Thenewsusieq]

Thanks again.....how do I know the U value of, for example, a square metre of FB brick wall?

 

[freddiemercurystwin]

Frankly I've not done a proper calc in about 20 years so would have to get my old books out to find the calc and work it out, or I'd prob just google the answer which says its about 2.2W/m²K, which is pretty bad. Ideally you want to be getting to about down to below 0.3 which means adding something like 50mm Celotex.

If you register on the Celotex website you can use the natty little U Value Calculator for free, which answers most domestic U Value queries.

 

[tony1851]

it would be worth trying to arrange a meeting at the property with the actual Building Control officer who deals with your area .

I suspect here OP would be better off using a private Building Control body - they are far more amenable/realistic than some LABC bods.

 

[tony1851]

Frankly I've not done a proper calc in about 20 years

So you've finally admitted it!

 

[freddiemercurystwin]

Frankly I've not done a proper calc in about 20 years

So you've finally admitted it!

Yes tony I have people do that for me!

 

[tony1851]

Frankly I've not done a proper job in about 20 years

......

 

[Thenewsusieq]

"A private building control body"??? Help! Do I have the choice? Don't LABC have the final say on everything?

 

[tony1851]

"A private building control body"??? Help! Do I have the choice?

Most certainly you do!

For many years, I used LABC on all projects, partly through inertia and partly as it just seemed like the default option.

But after long experience with several nit-picking, argumentative and condescending jobs-worths at LABC offices, I finally threw the towel in and now go with a firm of private inspectors (and never looked back).

Why pay the council to give you a good kicking???

 

[freddiemercurystwin]

"A private building control body"??? Help! Do I have the choice?

Most certainly you do!

For many years, I used LABC on all projects, partly through inertia and partly as it just seemed like the default option.

But after long experience with several nit-picking, argumentative and condescending jobs-worths at LABC offices, I finally threw the towel in and now go with a firm of private inspectors (and never looked back).

Why pay the council to give you a good kicking???

I disagree, I get good results from local BC, always have done. I guess it depends on your knowledge of the regs and how to argue your case effectively.

 

[tony1851]

Yes, but there are 'regs' and 'REGS'

I agree fire safety, structural safety and safe stairs are a must, but when inspectors start measuring the areas of vents, and the thickness of insulation..........