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by Ellis Woodman - The Wales Institute for Sustainable Education at the Centre for Alternative Technology is an impressive physical embodiment of the values it champions. When the Centre for Alternative Technology (CAT) was established 36 years ago, it took its place in a world still largely innocent to the threat of impending environmental calamity. As its name suggests, it was far from a mainstream organisation. CAT was founded by Gerard Morgan-Grenville, an old Etonian businessman who, in his late thirties, had become increasingly alarmed by his sense that mankind was living beyond the earth’s means. He found support for that concern among the hippy movement and travelled both in this country and the United States visiting counter-cultural communities that were exploring the possibility of self-sufficient living.
He found none of their efforts very persuasive and so bought a disused slate quarry near Machynlleth in central Wales and set about establishing a research centre there. That vision was supported by volunteers who came from all over the country. Often they arrived without skills or a means of supporting themselves but a number soon become permanent residents. In essence, CAT’s mission was to equip people to survive a post-apocalyptic future, whether the ultimate crisis came in the form of nuclear attack or, as the oil crisis of the early seventies had begun to suggest, a want of natural resources. While there was a strong streak of isolationism in that vision, it was always intended that the centre should be publicly accessible – both as a means of disseminating and funding its research. Visitors duly came to see displays on horticulture and fish farming alongside what were then the still rather esoteric fields of ambient energy generation, recycling and sustainable methods of construction.
Particularly over the past decade the context in which CAT operates has been transformed out of all recognition by the dawning awareness of climate change. Today, what might once have been dismissed as a community of cranks employs 90 paid staff and runs three postgraduate courses for architects and environmental engineers as well as offering
professional training for installers of photovoltaics and biomass generators.
To date, these activities have been accommodated in a pretty ad-hoc fashion, with courses being programmed outside the tourist season so that students could find affordable accommodation in local B&Bs. As of this month, however, CAT’s educational activities have at last been given their own designated building in the form of the £4.5 million Wales Institute for Sustainable Education (Wise). Accommodating 24 en-suite study bedrooms, a lecture theatre and multiple smaller teaching and research spaces, this 2,000sq m building is by far the largest on the CAT site.
It is the work of two architects who have already undertaken a series of collaborations at the centre: Pat Borer, one of CAT’s first permanent members of staff and author of The Whole House Book, and David Lea, who for the past four decades has operated as a sole practitioner from a smallholding overlooking nearby Cardigan Bay. Their earlier work together includes the stations of the extraordinary water-balanced funicular railway by which visitors access CAT’s elevated site. Having reached the top they find themselves on a 3ha platform cut into the hillside and liberally populated by Cretan windmills, geodesic greenhouses and pavilions made of recycled bottles. Among the larger buildings, are a number that serve as demonstrations of experimental technologies: a Walter Segal self-build house; a Borer-designed straw-bale theatre; and a shop and information building designed a decade ago by Lea and Borer together, which employs a structure of rammed earth piers.
The Wise building has also been conceived as an opportunity to use green technologies that currently enjoy only marginal take-up within the construction industry. And yet, discovering the building tucked away at the very rear of the site is to encounter an environment quite at odds with CAT’s prevailing air of hobbity rusticity. It reminded me of a small Oxbridge college, although one with the significant advantage of a view of Snowdonia from every bedroom.
Wise backs up against the steeply rising face of the quarry’s slate tip and extends forward to tie into a building that was originally a cutting shed but which has served as the site’s restaurant since it was brought back from dereliction in the seventies. This block all but screens Wise from view as we approach it, a surprising relationship and one that might be thought suspiciously expedient as its principal motivation was to allow the new building’s catering to be conducted from the restaurant kitchen. Wise’s reception area has accordingly been aligned with the restaurant and a large part of it given over to what is effectively a restaurant overspill.
Yet if this does feel an opportunistic arrangement, perhaps one man’s opportunism is another’s sustainability. Certainly, the sense of “making-do” feels powerfully communicative of CAT’s ethos. We don’t actually enter through the restaurant itself but rather through an adjacent section of the cutting shed that has been left open to the elements save for a roof of photovoltaic cells. This in turn takes us to a small gravelled courtyard, along one side of which the Wise reception is ranged. It is all rather labyrinthine, but appealingly so, the considerable dimensions of the building that we are about to enter remaining a mystery even as we reach its front door.
Lea and Borer have sustained a sense of measured revelation inside the building too. Passing to the back of the reception we are invited to process up a monumental stair of very shallow gradient which ascends to the foyer proper, one and a half metres above. It is only really on reaching this point, deep within the plan, that we are at last granted an understanding of Wise’s configuration. To our left lies a courtyard, visible through a wall of full-height glazing, and enclosed by teaching rooms on its remaining sides. This is the heart of the building, an intimately scaled external room, sparely planted and enjoying ample daylight thanks to the stepping back of the upper two storeys of residential accommodation from its edge.
The courtyard is one of three elements that frame the foyer, each of which follows a distinct geometry. Like much of the building, the courtyard takes its orientation from the cutting shed while the wing of offices and laboratories that closes the foyer’s far end runs parallel to the slate tip that rises behind it; lodged between them – looking in plan like a ball, grasped by a hand – is the perfectly cylindrical form of the lecture theatre.
This last piece is the dominant figure in the space, distinguished not only by its form but by its construction in rammed earth. At 7.2m high – a figure that is half that of the theatre’s diameter – the encircling wall is the tallest to have been constructed using this technology in Britain. The material’s environmental credentials rest on the fact that it provides a thermal mass comparable with that of concrete while boasting a very much lower level of embodied energy. It is constructed by laying successive 100mm layers of sieved and moistened earth within a formwork, each of which is compacted down to 50mm using hand-held pneumatic rammers before the next is laid. The resultant dark, pitted strata present a quasi-geological appearance that contrasts dramatically with the white painted finishes employed elsewhere.
One thing the material can’t tolerate, however, is exposure to the elements. The theatre is therefore encompassed by a second wall that charts a wider circle, thus establishing an ambulatory-like space in the intervening 2m-wide gap. Lea and Borer have put this void to good use, introducing a ramp that allows disabled access to the theatre’s lowest level, and transforming the external wall into an expanse of full height glazing where it faces due south. This last gesture allows the rammed earth to absorb heat by day which it can then radiate out at night and also admits daylight deep into the auditorium by way of a quite gigantic full-height door set within the theatre wall.
The theatre has also been equipped with a second – and no less dramatic – means of admitting daylight. Located centrally within its roof is a 5m diameter glazed oculus which, in the room’s dark state, is eclipsed by a plywood disc of equal dimension. The press of a button pivots the disc slowly clear of the skylight, a highly theatrical event which casts Pantheon-like light effects on to the beautifully detailed ash joinery below.
With the exception of the lecture theatre, Wise’s primary structure comprises a glue laminated timber frame, infilled with Hemcrete, a low-embodied energy material that incorporates a mixture of hemp stalks, lime and only a small quantity of cement. It has been spray-applied to a thickness of 500mm, the resultant build-up providing a high degree of insulation and air tightness while remaining breathable. As an essentially monolithic form of construction it is also less prone to technical failure than conventional cavity assemblies. At present, this technology remains – as Borer wryly puts it – “reassuringly expensive”, although he is hopeful that with wider application, costs may reduce. The architects are also optimistic that, with further research, it should become possible to employ a slimmer wall build-up – something that would make the use of the material in tight, urban situations a much more credible possibility.
At Wise, the Hemcrete has been finished externally in a coat of hydraulic lime render, its mustard colour offering a warm contrast to the dark backdrop of forest and slate. That relationship is felt particularly vividly on the terrace around which the building’s two upper levels are distributed. This space is addressed on two sides by ensuite bedrooms and held on the third by the closed form of the lecture theatre. On its fourth open side we are presented with the opposing tree-clad face of the valley, our elevated prospect serving to edit the middle distance entirely from view.
It is a spectacular moment – the intense interiority of the ground floor suddenly giving way to a relationship with a very much larger world. I was reminded of the roof terrace of Le Thoronet, the Cistercian Abbey in southern France where, in similar fashion, one can look both down into an intensely contained cloister and out into a vast landscape unblemished by building. Indeed, it is tempting to think of Wise as a kind of secular monastery. It is simultaneously a retreat from the wider world and a place intended to facilitate an intense engagement with that world’s problems. Lea and Borer’s building dramatises that very particular dynamic magnificently.
Doors and Windows: Learning by Example
October 2009 | By Amanda Birch
The Wales Institute for Sustainable Education not only teaches sustainable building, but will itself be a practical demonstration of techniques.
This article reviews three door and window solutions used in the project.
It’s a real eye-opener spending time with Pat Borer and David Lea. They are the first architects I have met who talk about the implications of climate change on the design of buildings in a very matter-of-fact and measured way.
As we walk around the Wales Institute for Sustainable Education (Wise), which they designed and are currently on site, they point out a sliding timber louvered shutter to provide shading to some south-facing glazed doors because, they say, sun screens on buildings will become increasingly important as our planet becomes warmer.
The two sole practitioners and experts on sustainable building have worked together intermittently with the Centre for Alternative Technology since its inception in 1974, designing some of the key buildings at the centre, which occupies a former slate quarry in the foothills of Snowdonia near the town of Machynlleth in Wales.
The £4.5 million (construction cost) Wise project is being built on the north-east corner of the centre and is due to be complete by late March next year following delays due to problems with the former contractor.
It is the biggest scheme ever to be built at the centre. An increasing interest in the environment and sustainable building technologies means demand has risen for the centre’s range of advanced renewable energy courses, and the existing facilities are stretched.
The Wise project will provide extra facilities with: a 200-seat rammed earth lecture theatre; a three-storey building housing 24 en-suite study bedrooms; three workshops; three seminar rooms; four offices; one laboratory and a restaurant and bar all arranged around a courtyard. In total, the centre will occupy an area of approximately 2,000sq m. Borer describes the scheme as being like a “mini university”.
A lot of attention has been focused on the 7.2m-high rammed-earth lecture theatre mainly because its innovation lies in both its height and its circular form, possibly a first for the UK. This attention is certainly deserved as it is an impressive space, with its sophisticated 5m-diameter plywood painted disc known as “the Moondisc”, which moves mechanically across the circular rooflight as a shading device, combining slick James Bond-style gimmickry with natural materials.
But its use of FSC-certified European timber throughout the project, including the complex’s glulam structural frame, is also of interest, most particularly how the European redwood is used for the frames to the doors and windows.
High-performance doors and windows made from FSC-certified timber were a given, but Borer and Lea were also concerned that the frames shouldn’t be too thick.
“The Swedes and the Danes manufacture some good high performance windows and doors but the frames often end up very chunky and wide, which we didn’t want,” says Borer. “We wanted to make the mullions more slender, so we decided to design our own and the contractor used Oxon Joinery from Shrewsbury.”
Lea adds: “We were trying to reduce the massiveness of the sections. Modern timber window frames are usually very clumsy compared to, for example, Georgian windows.”
All softwood frames were treated with Borax, a water-based mineral preservative, and the external frames were finished with an Osmo stain while the internal frames were sealed with an organic matt sealer by Auro. All double-glazed doors and windows incorporate a soft low-e coating, are argon filled and have thermal edge spacers.
Three different treatments for the external doors and windows feature on the buildings: full-height glazed sliding doors, which lead into courtyards on the ground floor and terraces at the first floor level, and to the first floor bedrooms; outward opening stable doors with a side vent at ground and first-floor levels to the laboratory and offices; and sliding windows with internal timber seats on the second-floor bedrooms and seminar room.
On the north side, small conventional window casements punctuate the hemp and lime walls, which are cast around the frame creating an insulated airtight and breathable construction.
Given Machynlleth’s damp but mild climate, courtyards and covered walkways are a prominent feature in the design of Wise, while glazed sliding doors offer the possibility to pull the door fully open. The sliding door frame is 56mm thick and each door is on average 2.3m tall x 2m wide. Siegenia Aubi ironmongery has been used throughout, in particular, a large brushed stainless steel door handle which can lift and release the door so that it can be slid fully across or locked in any position.
While in the laboratory and offices, hinged stable doors were specified because as David Lea says, “they are work spaces and are therefore more contained”. They can also double up as fire escape doors. The stable doors are approximately 2.7m high — 1.8m for the top section and 900mm for the bottom section. An integrated side vent offers user-controlled ventilation.
In the student bedrooms and seminar room, the sliding windows use the same ironmongery and system as the sliding doors and are also designed to be slid right across, opening up the space to the outside. The internal sustainable timber window seats allow students to sit and gaze out at the surroundings.
Timber-clad insulated walls — the same size as the sliding window — form the other half of the same window unit. The windows slide in front of the timber wall, which has been integrated into the design to give warmth to the square-shaped room. It also offers privacy and keeps the room cooler when it’s hot and warmer when it’s cold — a fully glazed unit might have made the room feel overlit and overexposed.
Lea says when they first looked into the design of the doors and windows, he was hopeful they could have a more frameless solution, but this proved too expensive.
They also approached the Green Building Store as they now sell high-performance doors and windows, but again, the high cost precluded its use.
Wise will inevitably attract interest when it finally opens, not only because of its size and use of sustainable materials but because of its design. This project is a lesson in how to design and build structures for living and working in a dramatically changing climate.
Full-height double glazed sliding doors lead off courtyards on the ground floor and terraces at first floor levels. Each door to the ground floor restaurant and foyer are 2.3m tall x 2m wide, while the sliding doors to the first floor bedrooms are 2.1m tall x 1.7m wide. The sliding door and window frames are 56mm thick. Siegenia Aubi ironmongery has been used throughout, in particular a large brushed stainless-steel door handle which can be pulled upwards, releasing the door so it can be slid fully across, or the handle can be pulled down, locking the door in any position.
Sliding bedroom windows
The second-floor bedrooms feature 1.7m high x 1.7m wide sliding windows. The same ironmongery and system as the sliding doors has been used and the windows slide right across, opening up the interior to the outside. A timber-clad insulated wall — the same size as the sliding window — forms the other half of the window unit. Internal window seats made of birch-faced ply and lipped with European redwood allow students to sit and contemplate the rural surroundings.
The outward-opening European redwood stable doors have been used to the offices and laboratory at ground and first floor levels. They are approximately 2.7m high – 1.8mm for the top section and 900mm for the bottom section – and they feature a side vent, which can be opened via an internal timber shutter. The handle is brushed stainless steel by Arrone. Adjoining the solid timber stable door, a full-height 2.3m-tall fixed double glazed unit.
Out of the Woods by Pat Borer