pIckING TRaDES aND FIRST FIx
Paul Testa is retrofitting his house to achieve peak energy efficiency, but it is not without disruption
Our ground floor design has an entirely open plan layout, and one thing that’s easily overlooked is where to place all the light switches. This requires a degree of imagination to visualise the finished ‘room zones’, trying to predict where people naturally reach for switches. The importance of getting this right won’t be lost on anyone with painful memories of being marooned in pitch dark bathrooms at parties desperately groping for
non-existent switches and pull cords!
As I pointed out the positions of all the lights and sockets to our electrician, Alex, he quipped that it was going to be really bright in the house and, in truth, we probably have overdone it a little. But since the additional cost of running extra cabling through the exposed shell of the extension is minimal, there’s no point being miserly. Even a Norman Foster-designed living space would soon lose its appeal with dim, parsimonious lighting, so it’s probably better to have too much illumination than not enough.
At this point in time I decided to revisit the interior design to see if any small enhancements would be beneficial. One of the main benefits of employing individual trades for the internal fit out (as opposed to a main contractor) is that it allows you the freedom to change your mind without driving everyone doolally and incurring extra penalty charges. So, after due consideration, I decided to improve the internal layout by revising the positioning of the stairs, making them more prominent and central, thereby creating a subliminal demarcation of the capacious ground floor space. The only major alteration required to achieve this involved repositioning a pair of substantial floor joists.
Having struck up a good relationship with Colin, the chippie, during the ‘phase one’ works, he kindly agreed to pop back for a day, despite being jampacked with work, to make the necessary changes to the revised stair opening for a reasonable charge of £180. There is of course a downside to directly employing individual trades — it’s all too easy to underestimate the time and effort you need to spend finding skilled people and getting quotes.
This was certainly the case when it came to getting the electrics priced. Although it’s a large
“If you’re not careful you can end up with a depressingly cheap finish that’s prone to damp and mould”
extension, the first fix couldn’t be simpler, with no awkward cutting of ceilings and floorboards required to the conveniently exposed structure. The trouble is, to price the job some electricians simply multiply the number of sockets, switches and lighting points by a fixed sum. Which explains why some of the quotes came in on the high side at over £6,000 (excluding the light fittings which we are providing). We have now appointed a local electrician based in a nearby village who priced the job at a reasonable £4,300 inclusive.
Fortunately getting prices for all the plumbing and heating work has been fairly straightforward. We ended up accepting a quote from Edward Smith who did a good job installing our new boiler last month. However, this still left one design detail unresolved — the question of where precisely to run the internal flue for the woodburning stove. The roof level ‘chimney stack’ flue was installed a couple of months ago during the roofing works, but working out the route down to where the stove will eventually be positioned in the living room without sacrificing too much space in the bedroom above has taken a surprising amount of planning. The Building Regs dictate that you’re only allowed to have four bends (of a maximum 45°) in the entire flue run, plus you need to leave a 50mm clear space between the twin-wall flue and any combustible materials including ceilings and floor joists. It’s also good practice to incorporate a rodding point so any blockages can be shifted.
It obviously made sense to discuss the flue design in advance with the installers, but two fitters who visited – one a curmudgeonly, almost Dickensian, character who admonished our modern stove within traditional brick fireplace design and the other a ‘take it or leave it’ salesman with the price to match – fell flat. It was the third, local chimney sweep and registered stove installer Ivan Staines, who saved the day. Ivan was very pleasant and clearly knew his stuff, and since I’m going to be buying all the materials it was helpful to discuss the shopping list for the various lengths of twin-wall flue. Ivan agreed a reasonable price of £350 to come back next month to fit the flue and stove. It was gratifying to learn that internally run flues generally perform better than external ones since the warmer indoor environment aids the flow of smoke upward and outward.
the ‘wet trade’ plastering altogether. But to obtain a professional finish this needs to be done with scrupulous accuracy. While this may be appropriate for a simple residential box design, given all the complexities with our sloping ceilings punctuated by multiple lighting and roof windows, in this case I thought it best to stick with a traditional skim plaster finish. Another factor to bear in mind if bare plasterboard is to be wallpapered directly, is that there’s a danger that a future resident might one day decide to steam off the wallpaper — taking the plasterboard with it!
Based on a set of drawings and my written specification, together with a tour of the extension, the first quote came in at £8,585 (for labour including VAT). The insulation materials will add another £1,800 but are down to me to source. The next two dry-lining firms we’d asked to quote eventually got back to us saying as much as they’d like the job they were struggling to recruit the necessary manpower for all the insulation work. It looked like we were going to be stuck with just the one quote for this mammoth task, so we asked a number of trades people we know if they, in turn,
knew someone worth approaching. However, once again the dreaded word ‘insulating’ seemed to inhibit suggestions.
Posting jobs online can be a bit hit and miss, resulting in being bombarded with ‘preliminary expressions of interest’ which turn out to be from trades located in far flung parts of the UK, or general builders with a policy of initially accepting every job! It doesn’t help that the categories of trades you can search under are often very narrow, with no option for anything remotely relevant to ‘insulators’, unless you just want your loft lined.
One of the best known sites is Checkatrade, which I hadn’t used before and hence was rather wary.
But it swiftly precipitated a useful list of local plasterers and dry-lining firms. I was aware that not everyone would relish the insulation work but one in particular caught my eye because of the impressively high ratings (from multiple reviewers that looked genuine), and whose work was local government approved.
A couple of days later a white van pulled up at our house emblazoned with the County Council logo underneath the words ‘Jamie Bosomworth, No Job Too Small’. Originally hailing from North Yorkshire, Jamie came across as knowledgeable and workmanlike. Later he emailed over his quote which came in a shade under the £7,000 mark excluding the materials (which I will be sourcing myself). As a one-man band, the job would inevitably take longer and we agreed a two-week target for each phase of the job, as with no pressing deadline we could afford to focus on quality and price rather than speed.
An eco retrofit has many positives, which include prolonging the life of existing building stock and reducing carbon usage. So, rather than build from scratch, we’ve chosen to retrofit our existing home. However, one big disadvantage is that new builds are exempt from VAT — whereas, perversely, retrofit is rated for full VAT. Another, if you’re already living in the house, is disruption. Getting your thermal and airtightness strategies right while minimising the amount of disruption you’re
willing to bear – without having to vacate the house for the duration of the build – is difficult to say the least.
We started with a ‘minimal disruption’ strategy — adding an external airtight and thermal layer would allow us to stay put during the works. It would also mean we could make our mark on the appearance of the existing building, as well helping us to unify any extensions. However, the party wall kept throwing up risks for this strategy that I couldn’t overcome without intrusive investigations. We’re architecturally one of a pair and drastic changes to our house made our adjoining neighbours understandably nervous.
So we’ve ended up with a ‘maximumdisruption-do-everything-internally’ retrofit approach. The detailing for this has, in many ways, ended up being easier to design. We do have to be more conscious of moisture risks with internal insulation, and we have a few more thermal bridges with internal walls breaking the insulation line. Most crucially, though, it also means we have to move out for the duration of the works — something that has taken my wife some time to come to terms with. We could stay but
the works would be slower and, ultimately, much more expensive. We just need to find somewhere to stay that’ll take a family of four, plus three cats!
For the extensions we are putting wood fibre insulation boards on the outside of the timber frame to minimise condensation risk; the construction becomes more vapour open towards the outside. The structural board that stiffens the frame is then on the inside and is vapour and air-tight; doubling its function.
I’m also using this retrofit as a bit of research and development for our design practice — I have to walk the walk if I expect our clients to take the plunge on these types of projects, so I’m using some materials that we haven’t tried before. It will be our first EnerPHit project (the energy efficiency Passivhaus standard designed for retrofit projects).
We’ve chosen to go so deep with our retrofit because we want our children to grow up in a comfortable and healthy home even more than we want to live in one. This isn’t about financial investment; it’s highly unlikely we’ll get close to recouping our capital investment in the shortterm, but our house will be futureproofed and won’t need further measures down the line.