humblebee hive – retrofit #9
The Shutter Saga – Handmade in Manchester
It’s been a while, but here it is… The post about external shutters!
(Incidentally, while the retrofit team were installing them and I was pondering this article, Spotify suggested this “Made in Manchester” playlist – why not give it a listen while you read…)
I’m sat in our little Tuscan agriturismo lodge on an organic farm, grateful for the split DX unit that’s currently keeping us relatively comfortable while temperatures outside soar to 38oC for the third day running so overheating is once again at the forefront of my mind!
Having driven through France and Italy for our summer holiday this year, touring a varied European countryside, we were reminded of all manner of external shading devices on our way down, and especially my favourite: louvred and side-hinged timber shutters, generally painted bottle green or chocolate brown (or is it espresso?), on a background of anything from cream or yellow, through to earthy-coloured and terracotta rendered walls.
An important aspect of Passivhaus design is orientation and reducing overheating risk, which can be controlled by keeping windows small and having enough openable ones (to a large extent). And the robust solution is to cut out the gains before they get into the space, without compromising the beneficial winter sun, which is why orientation-appropriate external shading is your best investment: it allows you to maximise solar gains in winter, enjoy the views and framing of the countryside, and yet keep the unwanted heat at bay.
But what can you do when orientation and window sizes are a given, as they are with an existing building, and when shading isn’t part of the vernacular?
This was already a concern for us as our South-West facing windows were causing discomfort on particularly warm sunny evenings – even before we switched to triple glazing – and opening the windows at night was always a choice of whether to be too hot and not sleep or hear the aeroplanes and not sleep… (Manchester Airport proud to be stricter with their noise restrictions than Heathrow and Gatwick… big whoop and eye roll).
An early consideration in the retrofit plan was therefore how to keep heat gains from low angle sun under control, especially as they occur later in the day, coinciding with the warmest air temperatures, and effective at warming up the spaces we’d most like to keep cooler at night: the bedrooms.
We had a few technical issues to consider however:
- It’s relatively straightforward to drill supports into a masonry wall, but when covered by 200mm of woodfibre insulation and render… less so.
- The window openings themselves are wider than the stretches of opaque wall either side and between them.
- There was barely any wall left above the window and below the eaves, and the eaves were only just overhanging the window once the EWI was installed.
- When commercially available shutters – ahem, define “available” – are conceived without taking into account thermal bridging, what are the fixing options?
Then there’s the cultural and therefore supply issue that shutters just don’t form part of the vernacular or even modern housebuilding despite ever tightening of insulation and airtightness regulations, however slow this may seem.
So although it was always at the back of our minds, it was filed in the “too hard” pile, and actually solving it got kicked down the road on numerous occasions (I’ve reframed all procrastination as “thinking time” ;-)… Recommend!)
Having said that, we didn’t totally ignore the issue, and I’d asked Russel – one of my collaborator architects – to sketch out some initial details and suggest some suppliers which helped inform our thought processes.
Once it was on paper, we realized we couldn’t find a way to have hinged – even multiple hinged – shutters to fit our window, and bearing in mind only one third of the glazing was going to be openable and to one side, so we would have struggled to open and close them manually, let alone maintain them.
Sketch by Russel Hayden (Hesketh-Hayden Architects)
So before the retrofit team started on the full works, we sat down and discussed what we could put in as supports that wouldn’t be too much of a thermal bridge. One of the team suggested using Purenit so they fixed two 100 x 100 rails above and below each window to have something to drill into when we needed to.
In the meantime I researched what was available on the market and tried to obtain quotes. Having obtained some astronomically high numbers from commercial suppliers, I tried to find more standard companies to no avail. Plan B was to try and source them from the continent, but many of the websites I found only supplied plastic or aluminium – which I guess makes sense if you’re trying to keep the installation lightweight – and it didn’t “sit well” in my mind in any case.
At this point I was going to quote the poem “This is the Place” by Tony Walsh, but Forever Manchester’s licence fee proved prohibitive so here’s a link so you can read it yourselves, and I’ll paraphrase: we concluded that the way to do it in the Northwest of England was to start from scratch, and have it handmade. We’re blessed with a plethora of local craftspeople, and someone always knows someone who does…
So having contacted Treestation – a Manchester CIC that processes timber from urban tree management activities – for a potential source of wood, they put me in contact with the lovely Ben Thomas at the social enterprise Start Creative that does bespoke joinery.
After a brief chat and initial quote for design, manufacture, supply and fit – anything seemed reasonable after those commercial quotations – we were on our way, or so we thought…
To cut a long story short – I know you like it when I give you detail but trust me this is just dull – we to and fro’d with options, numbers of panels, wood type and finishes, and timber grading and supports and sliders and frame and the result… well you can see for yourself. It wasn’t without a bit of stress and quite a lot of delay, but we are dead chuffed.
I include the design drawings here which we’ve agreed can be used under Creative Commons (please feel free to use as a basis, but credit Jonathan Woolley and Ben Thomas and remember to check out its applicability for your own project including all the structural calculations).
And my lovely retrofit team were back on the scene in April – nearly a year later – to make sense of the telescopic sliders (hung) supplied by the aptly named sliding-door stuff and find a way to fix it all (thanks to the lovely technical person at the other end of the phone)… As the wind was gently pushing them back they even came up with a magnet arrangement: strong enough to hold it open when needed but “tuggable” to close again.
The Sioox treatment went on and now the shutters are the same washed out hue as the cladding, albeit a different wood (Douglas Fir).
We’ve had so many lovely comments from passersby and friends who have visited… many said how European our house looked (boom!!)… all we need now are window boxes with bright red geraniums to feed the bees and complete the dream. Cue my cabinet maker, talented gardener and dear friend Garry to guide my son T with an autumn craft project. Keep watching this space!
Next time… we’ve gone for an Earth Floor! And Building Control don’t understand it… send thoughts and prayers… and help!!!
Manufacture and supply £2,600
Sliding door mechanism – telescopic, Saheco, £518.78 (incl VAT and P&P)
Sioox primer and treatment £147.82 (incl. VAT and P&P)
Total Retrofit to date £68,567.60 (£623.34 / m2 GIFA)