Number 139 Kings Road, Bury St Edmunds is a 12-apartment, three-storey block built for Havebury Housing Partnership and the Orwell Housing Association. Its a striking rectangle of a structure, overtly declaring its
environmental credentials right on the street front. I-joist based wall and floor cassettes form the core structure, the cladding is two layers of unplaned sawn larch, the window frames are in lime-washed but otherwise
unfinished oak and the whole building is wrapped in a planted screen of larch and stainless steel wire rigging.
Coming at it through the surrounding Victorian terraces it is an eye-opener and, unsurprisingly, it provokes opinions. In fact, people cant seem to pass by without expressing one.
The other day I was taking some pictures and this young guy just stopped and said how great it was to have this all-timber, ecologically-sound structure, said Scales. He then launched into the Gaia theory, but it was interesting that the building gets this kind of response.
Predictably, as it breaks so radically with the local vernacular although it has some stylistic themes in common with the modern shops on the other side to its Victorian neighbours not everyone gave the building such a warm reception.
It is on the fringe of a conservation area and getting through planning was a battle, said Scales. The officers went for it in a big way, but the committee turned it down. We made modifications, but they refused permission again. We eventually got through on appeal.
The conservation officer also had reservations.
He thought the building would overwhelm the houses around the corner, so wanted it stepped down at one end, said Scales. We said this would destroy its integrity and he eventually came round. In fact, he really liked the end result!
There are no two ways about it, 139 Kings Road makes a strong statement, perhaps even more so given that its studiomgms first completed project. But if youd read the companys prospectus on its website, it probably wouldnt have come entirely as a surprise.
The practice is a three-way collaboration between Mole Architects, Greenyard Architecture and Modece Architects, where Scales is partner, with the division of labour depending on "whos busy and who has a particular interest in a particular building.
Were pooling resources to take on larger projects, but what brought us together was shared aims and interests, said Scales. Were all passionate about ecological design and sustainability and were all passionate about good architecture.
One expression of this philosophy in studiomgm designs is extensive use of timber. In fact, its one of its starting points.
To meet modern insulation requirements and for the sake of the environment generally, we all have to use more timber, said Scales. We push it for structure and cladding why on earth build a timber-frame house then skin it in something structural like brick? In fact, the only instances we dont use it is where clients or planners wont have it.
Besides winning over nervous planning committees, another test that remains for the timber-oriented UK architect is finding builders and contractors with the skills and experience in using it, particularly in designs that demand something different. So it proved at first on Kings Road.
We wanted a heavily insulated, breathing wall construction, but some timber frame fabricators would only use standard 140mm studs, presumably because thats what their machines are set up for, said Scales. They also wanted to use an outer plywood skin, which would have been a vapour check potentially trapping moisture in the wall. If you use plywood, you want it on the inside.
Eventually, in Essex-based New World Timber Frame, studiomgm found a fabricator which gave it what it wanted; prefabricated structural cassettes based on JJI-joists, comprising softwood flanges and OSB web, with 240mm versions used in the walls and floors and 300mm in the roof.
By using I-joists you get less movement than with solid timber, said Scales. They also accommodate more insulation and reduce the risk of cold-bridging.
The structural panels have an exterior skin of Panelvent, Paneline on the interior and Warmcel recycled paper insulation pumped into the cavity. To improve their energy performance of the structure further, services are fitted in the gap between the Paneline and the batten-mounted plasterboard on the interior.
We wanted to minimise air infiltration in the external envelope, said Scales, so we also sealed around the outside of the Paneline with Airstop tape from Isocell, which my partner at Modece, Ralph Carpenter, discovered researching Passivhaus building in Austria. This ensures the insulation works properly, keeping it free of cold air.
The earth pipe vents on the roof draw air through the building, keeping it warm in winter and cool in summer
Another environmental objective for studiomgm is buildings that are low maintenance, hence the use of
untreated wood on the exterior.
The cladding is detailed so the end grain is protected and the windows, which we had to have made specially by JS Hay in Norwich, were lime-washed to prevent moisture getting in while the timber was getting used to the atmospheric conditions, said Scales. Other than this, the wood is just left to age and silver naturally.
The timber has not been fire treated either. We avoided that by having sprinklers throughout the building, said Scales. This also meant we could have the cladding the whole height of the building and a flat layout with bedrooms leading off the living area, rather than a lobby which would have wasted so much space.
Adding to the eco-package, the flats have showers rather than baths, taps are aerated and harvested rainwater is used to flush loos. Ventilation is also all natural, using a variation on earth pipes. Air is drawn up these passively from a plenum under the building, where it is tempered, to stacks on the roof, helping to warm the flats in winter and cool them in the summer.
Larch louvres on south-facing windows and the green screen will also help prevent overheating. Within three years the latter will be covered in wisteria and clematis, automatically irrigated from the harvested rainwater.
The screen will not only provide shade, the transpiration from the plants will moderate the air around the building and have a further cooling effect, said Scales.
If it had been equipped with a wood-fuelled heating system and solar panels, 139 Kings Road might have achieved zero carbon status. But these would have bust the £1.2m budget and, given the location, delivering wood pellets would also have been problematic. Instead, all the flats are heated and get hot water from a central conventional gas-fired boiler. Even so, the building still achieved a BRE Ecohomes Excellent rating with a total heating load of about 24kW.
Sitting on concrete foundations and brick plinths, the prefabricated panel shell of the structure only took around four weeks to erect, but proved quite a logistical challenge.
Its a narrow site, with the pavement forming the perimeter at the front and very little room at the rear, so it needed careful planning to deliver materials and meant the contractors had to start one end and work their way along, said Scales.
From thereon in, construction took another 13 months although two of those were spent waiting for the electricity company to shift a mains cable that shouldnt have been there and the block was fully occupied in weeks. And while it initially raised some eyebrows, it now seems to have started a trend in the town, with local residents acclimatisation to cutting-edge wood building being assisted by Hopkins Architects timber-rich redevelopment of the old cattle market just over the road.
studiomgm, meanwhile, has moved on to its next project, the new Norfolk headquarters of Liftshare, the car-sharing social enterprise. This will also be timber-based and ultra-energy efficient, using earth-pipe ventilation and wood-fuelled stoves which will only have to fire up on Mondays as the occupants and computers will generate the heat needed the rest of the week. Uncompromising is probably the word for its looks too. At the suggestion the earth pipe outlets give it the air of a modern day maltings, Scales said they were thinking more state-of-the-art chicken farm.
The 12-apartment block is on the fringe of a conservation area