Our Green Deal - the process

3/13/2014

Despite months of preparing and chasing to get a Green Deal since March 2013, our actual Green Deal installation happened to coincide with my main PhD research in winter 2013/14. This meant I did not manage to blog about the process as we went along; but I did end up taking many pictures - often once the installer had left for the day and I returned from my fieldwork. It also meant that I missed out on being there for several crucial stages. For example it was my husband who was around when Instagroup came to inspect the works on two occasions; when the window cills were measured and installed and reveals insulated (only very few); when the insulation was mechanically fixed and gaps filled; the eaves capping was installed and I was also not present when the services were finally insulated and boxed in nor when the rendering and painting took place.

Being unable to witness and influence the Green Deal installation process is definitely frustrating as an architect (and when knowing a thing or two about thermal bridging), though it probably prevented me from becoming the 'client from hell' by interfering. As such I do think that our experience and installation is probably fairly typical of a Green Deal installation and I will write another blog about some issues with standard detailing and trying to find solutions with the installer (who were as flexible as they could be within the constraints of Instagroup's EWI system and Green Deal approval).

Actually, I bet you can identify some of these issues and (potential) problems from some of the photographs below, without my commentary? Do leave comments!

Back facade before; with EWI during installation; just rendered and finished

Roof insulation and waterproofing (not Green Deal)

The existing roof basically was just some asphalt on timber boards over timber joists. You can see here where the previous owner had the chimney removed and had run a new piece of asphalt across this gap! On the right is the new roof on top of the old: 18 mm OSB + vapour barrier + 100mm ECOTHERM insulation board (k=0.025 W/mK) + underlay + waterproofing. The new timber edge is to enable the 100 mm insulation and the roof also overhangs by ~ 150 mm over the wall to meet the 100 mm EWI at later stages, avoiding typical EWI Green Deal capping systems for most of the roof - see pictures. NB: We will still need to insulate in between the joists from the ceiling at some point,...

Roof insulation overhang created to meet later EWI. Not thermal-bridge free; but better solution than typical Green Deal 'capping' detail, which we could not avoid at the eaves of the pitched roof section. (see images to right)

EWI installation process

Our Green Deal process has finished exactly a year later - and we have just submitted paperwork for our cashback.

Firstly, scaffold was installed in late November to enable flat roof insulation and new waterproofing, a process which took < 1 week. In early December, the scaffold was adjusted further away from the walls to allow for future EWI installation and things initially took off quickly. However, soon delays occurred due to darkness setting in sooner at that time of year and on many occasions the guys on site had to wait until temperatures were > 5ºC and rising to glue the insulation to the walls. As a result the works did not finish before Christmas and New Year 2013, and around this period much of the UK witnessed extreme weather leading to further delays on site: rendering and painting can only happen when there are several days of dry weather so there were several weeks where nothing could happen. A few Green Deal installers told me that they had been under pressure to render several houses to finish on time (before the cash-back ran out or ECO would be scrapped) and overnight rain washed the render away and it had to be all scraped off and redone at another time - so things could have been worse I guess!

Our window cills also took almost 2 months to arrive!

EWI installation stages

Existing render is scraped off.

Numbering of boards ready for removal to glue and fix

More glue in some locations is used to help realign uneven walls, applying it it lines on all 4 sides and with a line in middle - supposed to stop air circulating in any gaps.

In this location the installer had glued the insulation but was not happy with it and it was removed

more gap and joint filling

Unfortunately our window cills did not arrive until late February and they were left exposed to the elements for almost 2 months,...(you can also see here how little space to insulate the reveals)

The insulation system was taken right up to the services. Image below shows after insulation + boxing in of services with purpose made aluminium panels.

While our services boxing-in details are awkward (I'd have preferred increased insulation thickness and then a flush boxing in of the pipework, but this was not possible with our Green Deal system), it is not as awkward as the standard Green Deal detail if pipes cannot be moved; i.e. to insulate 20-25 mm behind the pipes and render this.

Finished back elevation; though external light still needs connecting.

100 mm graphite coated EPS with a 'tongue/groove' system. Easy to cut, but leaves loose beads everywhere!

Cutting, placing and fitting of boards

Glueing can only happen in temperatures of ≥ 5ºC and rising.

Gap filling to minimise thermal bypasses and thermal bridging

Mechanical fixing with thermally broken screws to the brick wall; 2 screws per insulation board. Then joints are filled.

New GRP window cills are placed and in this case some aerogel insulation could be placed under it.

Same window cill finished

rendering of the insulation; note the services here are exposed and uninsulated. They could not be moved due to window locations. Images below + left show services boxed in (after the wall behind it and the services were insulated as much as possible) and wall painted.

The EWI detailing and green deal process is not perfect by any means, but it has given us a house which is definitely much better than before.

Aside from being more comfortable, and (hopefully!) having our bills reduced), daylight in our house is much better despite the deeper reveals, due to the reflection of light on the white reveals.

NB: I will be taking some InfraRed images too and will post them here at some stage,...

5 Comments

Gordon Santana

3/16/2014 09:59:23 pm

Hi Sophie,
It's been interesting to read about (and see) your experiences throughout the process.
Is there any chance you could share, publically or privaterly, the top-line financials in terms of costs, ECO subsidies and cashback?
I hope you get rewarded with a decent long term reduction in post retrofit energy useage, I'm sure you will.
Gordon
PS did you draw on any Green Deal finance?

Sofie Pelsmakers

3/16/2014 10:13:41 pm

Hi Gordon, I will do an update on finances once we have paid the final balance. In brief I listed costs here and ECO contribution: http://www.sofiepelsmakers.com/5/post/2013/09/-the-green-deal-significant-differences-offered-in-ewi-eco-funding-it-is-worth-to-shop-around.html but I didn't write it very clearly as we were still in the midst of it all. Basically , the flat roof insulation + waterproofing was around £2250 incl VAT and originally just under £5000 for back wall insulation, BUT of this we got £3400 ECO grant and £650 cashback; so we are due to pay about £1000 though we will have to pay a bit extra for the window cill upgrade (standard = aluminium) and the aluminium boxing in and we have not had the latest costs in yet - will post it on here when we do get it.

In brief, we'd do it again! We could not have afforded it any other way. So while not perfect by any means, it is better than the situation we were in before. We started the process under the green deal. It was only upon finding out how much ECO-grant we'd get we did not need to get green deal finance - which we had trouble getting installers to give us anyway as it was so early in the process. ECO and green deal are obviously closely tied together - I think government made a BIG mistake by counting those who get any level of ECO grant under ECO stats and not under the Green Deal - I am not surprised the GD stats look so bad, as many people will be able to get some level of ECO funding but only those who borrowed money to get works done will be under the Green Deal.

Ben White

3/26/2014 09:30:39 pm

Looks like your installers did a careful job (e.g. removal of existing render). Think this is quite unusual...!

We are in the process of a complete EWI job (all 4 sides of a detached house) in South London, and they just stuck the boards over the existing facade, lichen and all. Didn't even bother with a fungicidal wash.

Generally, I have found that they just want to get the job done ASAP, and don't really consider the long term issues (e.g. burying taps and wate pipe joins in the render, lack of detail around window frames and weep holes).

I am reasonably well informed and have kept on top of them but for the average EWI job, I can see this speedy installation without thought for the long term could be a big issue in future.

Ross link

3/27/2014 07:14:14 pm

Hi Sofie,

We're about to embark on a similar journey with the back of our terrace.
Already off to a bad start - had British Gas round to do a green deal assessment (even though I had no intention to use them- just wanted the piece of paper), only to be told by all the installers that I've contacted that they won't use their report and that they will do their own....

So far I haven't been able to secure any ECO funding ( not enough of a carbon saving to meet the big 6's criteria), however the government cashback was recently increased from £650 to £4000 so we are hoping that we can afford the difference without having to take the finance.

May I ask how they dealt with the detailing between your back wall and the roof of the small extension? Did they redo the flashing to the new render or just place the insulation over the existing flashing causing a cold bridge?

Many thanks

Ross

Boiler breakdown cover link

4/17/2014 03:22:07 am

It's great to read such an in-depth blog about someone's experience with the Green Deal. Even if you're not totally satisfied with the results of the process, you should count yourself as lucky to have actually received energy efficiency upgrades through the Green Deal - a lot of people never get that far!

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