Options for solid wall insulation?

Dear Jessica,

Sure, I'll try to be as much help as possible!  I'm not sure I'll be able to give you exactly what you want though...

I haven't got any prices from Green Homes Concierge yet but I will contact them if you'd like me to.

In terms of external wall insulation... GHC put me in touch with a contractor who told me over the phone that my end-of-terrace house wouldn't be suitable for external insulation (for a number of reasons) so I didn't get a quote.  A friend told me that external insulation installation typically costs £10,000 for a 3-bed end-of-terrace.  This figure matches nicely with the only prices for external insulation I have been able to find online (scroll down to the section marked "cost implications").

If I was hell-bent on installing external insulation (and if the planning office and my neighbours were happy) then apparently I could install it myself but it would still require a scaffolding rig etc.

In terms of internal insulation... So far, I've only researched the prices assuming that I would be doing all the labour.  The cheapest prices I've found for 70mm of rigid foam insulation bonded to plasterboard is £28 per board (2400x1200mm) from aandainsulation.co.uk.  70mm of polyurethane glued to my 9" solid walls should be just about enough insulation to achieve the Energy Saving Trust's "best practice" u-value of 0.30 W/(m²·K) (compared to building regs part L1b 2006 which require 0.35 W/(m²·K)).  This board can quite literally be glued onto the existing internal wall (assuming there are no existing damp problems).  Here are some prices from my own DIY project:

Livingroom walls (original U-value = 2.1; target U-value = 0.30)
25m² (9 boards) of 70mm insulation bonded to plasterboard = £252 = £10.25/m²

Livingroom floor (original U-value = er, somewhere near infinity!; target U-value = 0.24)
25m² (9 boards) of 100mm insulation foil faced = £207 = £8.28/m²

These prices are for so-called "seconds" insulation but the chatter on t'interweb suggests that the "seconds" insulation is just fine.

So, as you can see, I'm hoping to achieve the EST's best practice U-values for around £10 per square meter (insulation materials only).  Going from a U-value of 2.1 to 0.3 will reduce the heatloss through the walls by a factor of 7!  The price will probably creep up to about £12 per sq meter once I've bought the adhesive, plaster, paint, replacement skirting board, new mains sockets etc.  But I guess these figures aren't hugely useful for you because you need "materials plus design plus labour".

I've emailed Procter to ask for their prices for their Aerogel insulation products (which have about half the thermal conductivity of polyurethane; hence half the width is required to achieve the same performance).

I'm very happy to shop around for some quotes for how much the installation would cost if I paid someone to do it if you'd like me to.

Thanks,
Jack

Thanks, this is really useful. 

Don’t worry about getting any other quotes, I’ve emailed GHC myself (just waiting to hear back from them).

This is interesting though, clearly quite a range in material costs.

Kind regards
Jessica

Jessica,

I was thinking about Aerogel somewhile ago, but hit a brick wall.

What happened regards your Aerogel thoughts?  I would have thought costs would be prohibitive.

Regards

.

Thanks Jack for the useful information. I am having an extension put on my home later this year and I too really need to make sure I get some prices for wall insulation. The insulation in my home is not that great and I want the extended area to be much warmer so we're willing to pay for the higher end materials.