Improving U value of house walls and Part L

[stuart45]

Wavetrain,
If you keep all your receipts and take photos of the work in progress then I would accept that as proof of internal insulation for a EPC. If the DEA won't take this, tell him you will put in a complaint to his AS. BRE for example charge £600 to the DEA to check it on site regardless of the outcome.
However internal insulation does have a downside as 9 inch walls rely to some extent on heat from the house to keep them dry. The heating system has the biggest say in the RDSAP rating.

 

[jeds]

Is there any way that the improvement made to the insulation of the house be recognised at time of sale?

Yes, get it signed off by building control.

But then are'nt we going to be back to the problem of BC requiring any renovation work to make an improved wall meet the current regs and as I explained before, if I insualte the wall with more than 25mm celotex which is next to the stairs, then the stair width would be too narrow...

wavetrain,

Adding insulation to a house (apart from certain types of cavity wall insulation) is not a controlled operation and you do not need building regs. If you keep records of what you do the added insulation will be accounted for by an energy assessor. Believe me, the difference between 25mm and 50mm PUR foam up a staircase will barely show up in the figures and is extremely unlikely to make any difference to your overall energy band.

Building regs may apply if you are renovating more than 25% of external walls (i.e. re-rendering) but that part of the regulation is specifically designed to take advantage of the opportunity that would arise out of the renovation. It is not designed to enforce overall upgrading of thermal elements just because you are carrying out works.

You did not mention external render in your original post - why are you not considering adding insulation within the new render?

 

[wavetrain]

jeds, thanks for your post.

It was in fact nosell who mentioned rendering towards the beginning of this thread, it was never my intention to add insualtion outside since the roof would no longer overlap the walls:

EXTERNAL WALLS:

"Where 25% or more of an external wall is re-rendered, re-clad or re-plastered or re-lined internally or where 25% or more of the external leaf of a wall is re-built then regulations would normally apply."

Thinking about this started with the need to replace windows as they are well beyond repair and by adding some 50mm urathane or eps under the odd bay and wall here and there, adding a litle kitchen exension to bypass other 9" walls and opting for argon and low-e I could get the overall U value of almost all the walls down to a 1/4 of what it currently is. Our gas bill right now...

 

[jeds]

Of course the windows are controlled works and require either building regs or FENSA certification. But the insulation is not and you can do what you like. (given that you don't do anything that is going to cause a technical problem - like condensation) My advice is add 50mm wherever you can and as much as practical elsewhere.