New build - no wall insulation

Mattpoker

Bought a new build 4 years ago from Miller homes. We've just had some work done and the builder noted we have no wall insulation between our end terrace and the house next door. That's not right, is it, maybe even legally? Can we ask for Miller to now sort it out or has it been too long? Wondering if anyone has had the same problem.

ComicGeek

More likely that it's designed without insulation in the party wall, still possible to comply with Bldg Regs without it. Worth asking them if it should have had it installed, but very likely that it wasn't needed at the time.

Davesnave

Cavity walls between properties were commonplace 4 years ago. As early as 2011, the NHBC had become aware of problems with not closing them properly or insulating them to prevent air movement and heat loss. However, I'm not sufficiently clued-up on the alternatives to offer any advice re meeting regs for u values etc.


Is the house under guarantee from the NHBC or similar?

ComicGeek

Davesnave wrote: »

Cavity walls between properties were commonplace 4 years ago. As early as 2011, the NHBC had become aware of problems with not closing them properly or insulating them to prevent air movement and heat loss. However, I'm not sufficiently clued-up on the alternatives to offer any advice re meeting regs for u values etc.

You can still build a party wall today without insulation as long as the edges are sealed.

It's even possible that the OP's house was a later part of a large site which was registered under the older 2006 Building Regulations that didn't consider heat loss through party walls. I'm still involved in a couple of sites that will be building to 2010 Building Regulations for the next 6 years....

Mattpoker

Thanks for the replies.
'Is the house under guarantee from the NHBC or similar?' - Yes it is.

I was hoping we could get some cash back as we seem to spend more on heating than others but I guess the insulation rules aren't clear cut.

Davesnave

Mattpoker wrote: »

Thanks for the replies.
'Is the house under guarantee from the NHBC or similar?' - Yes it is.

I was hoping we could get some cash back as we seem to spend more on heating than others but I guess the insulation rules aren't clear cut.

The builders should be able to tell you how the walls were constructed and how that meets building regulations. This means writing to them, not phone calls.

Then you'd need to decide if it was worth having an independent assesment using a cavity camera to see if something wasn't done correctly.

The builders should rectify any proven defect in the structure, but there will be no cash pay out.

bris

There won't be any heat loss between two homes, the walls that need insulated are the external ones for obvious reasons. I think you are clutching at straws tbh.

markin

bris wrote: »

There won't be any heat loss between two homes, the walls that need insulated are the external ones for obvious reasons. I think you are clutching at straws tbh.

If it was a solid wall, but won't the be heat escape at the roof, could the be cold spots at the front wall?


Anyway if i like my home at 22c and next door keeps it at 16c and just puts a jumper on i don't want to heat his home.

Davesnave

bris wrote: »

There won't be any heat loss between two homes, the walls that need insulated are the external ones for obvious reasons. I think you are clutching at straws tbh.

Poor cavity construction/insulation between homes was an issue the NHBC particularly wanted to address in 2011, along with matters of sound transmission. It's easy enough to findthe reference.
www.nhbc.co.uk/NHBCpublications/LiteratureLibrary/.../filedownload,43252,en.pdf

Were they wrong to flag it up as a matter of concern ?

marlot

Mattpoker wrote: »

...
I was hoping we could get some cash back as we seem to spend more on heating than others but I guess the insulation rules aren't clear cut.

Assumign that the house next door is occupied, their internal temperature is likely to be about the same as yours. So there won't be any heat lost through that wall.

ComicGeek

marlot wrote: »

Assumign that the house next door is occupied, their internal temperature is likely to be about the same as yours. So there won't be any heat lost through that wall.

There will be if there's an unfilled, uninsulated cavity between the two houses. That was the whole point of the Part L Bldg Regs update in 2010 - there was additional energy usage in terraced houses that researchers couldn't pinpoint, until it was realised that air circulation in cavity party walls was actually a very significant heat loss.

The SAP calculations assume a U-value of 0.5 for uninsulated cavities without sealed edges; a U-value of 0.2 for uninsulated cavities with sealed edges; and U-value of 0.0 for insulated cavities or solid walls. These aren't necessarily exactly accurate, but allow for the effect to be included within the calculations and EPC.

A U-value of 0.2 is equivalent to a modern build - 0.5 is equivalent to a pre-1980s build. So a mid-terraced house's energy usage is going to be dominated by the quality and construction method of the party walls.