Sapa Building System technical essay: Felix Mara on award-winning envelope design
[The Sapa Building System technical essay, RIBA Awards 2012] More than the plan, more than the section, and even more than form, the envelope is central to how a building communicates, writes Felix Mara
You might well ask why, as in previous years, the AJ has accompanied most RIBA-Award winners with a typical external view, seen at eye level by someone standing close enough to see detail, but far enough away to be able to read the overall building form.
Why not a typical floor plan, section, or aerial axonometric instead? Aren’t we missing an opportunity to show the bigger picture by using images that reveal a project’s inner workings in a more abstract, diagrammatic way? Shouldn’t we listen to Le Corbusier’s dictum that the plan is the generator or attempt to show what Loos referred to as the building’s raumplan? Surely the interior of a building is most crucial.
Actually, these external views are the bigger picture. More than anything else, it is the building’s envelope that communicates its essence most directly and comprehensively.
All well and good, you say, but don’t these views emphasise superficialities? Are we victims of a pathologically image-conscious and brand-fixated epoch? Clothes make the man, some say, but it’s much more satisfactory if people shine through their clothes rather than hiding behind exteriors. It’s certainly true that some building envelopes are crudely emblematic, but it’s also true that those with simple shapes and wallpaper-like facades can combine to form compositions that just feel right, perhaps as external rooms or corridors, to use Camillo Sitte’s analogy.
Interestingly, there is less architectural wallpaper on show among this year’s RIBA Award-winners than in the past. Make’s Cube in Birmingham is one of the exceptions, although it is also an example of a building with a strongly patterned facade that, nevertheless, offers glimpses of what lies behind. In any case, it’s debatable whether all buildings should reveal their interiors.
Alvar Aalto, for one, had no time for this dogma. He was far too subtle to insist that the external walls of perimeter staircases in his buildings should be glazed. Putting building performance to one side, opaque envelopes are OK. But, then, so is transparency. Notwithstanding Ken Shuttleworth’s breast-beating recantation after years as a glass facade man and the doom, gloom and pepper pot facades predicted in the wake of the last round of energy conservation restrictions imposed by Approved Document L, the all-glass facade is alive and well.
Although some designers are increasingly wary of formulaically and uncritically rolling it out as a panacea to give commercial clients ‘what they want’, Wilkinson Eyre’s Guangzhou International Finance Centre and OMA’s Maggie’s Centre in Gartnavel testify to the ongoing popularity of the glass facade. Devices such as twin walls and heavily insulated roofs and floors help ward off the threat of increasingly stringent standards and rising energy costs.
Here, the ideal of the flush glass facade continues to flourish, invigorated by inventions such as the toggle fixing and bolt connections embedded in glass panels. Many of this year’s winners, for example BFLS’s Royal Welsh College of Music and Drama, juxtapose transparency and opacity and, as Stanton Williams’ Eton Manor and Sainsbury’s Laboratory at the University of Cambridge demonstrate, the art of facade composition is thriving.
The architects of some of this year’s winners avoided cloaking their buildings in mantels of over-cladding, choosing to articulate structural elements and, in some cases, component volumes instead. O’Donnell + Tuomey used brickwork, with interstitial glazing to articulate the volumes of the Lyric Theatre in Belfast, revealing the complex geometry of its internal spaces, whereas projects such as Sergison Bates’ urban housing and crèche in Geneva, express their structural frame. Others, like Rogers Stirk Harbour + Partners’ Las Arenas in Barcelona, have a rich layering of structure, circulation, services and envelope components, while Eric Parry Architects’ Holburne Museum in Bath uses glazed ceramic ribs to create facade texture.
The level and quality of tectonic invention in these envelopes is extraordinary, not least in Feartherstone Young’s resourceful Dellow Day Centre and David Chipperfield Architects’ Turner Contemporary, an altogether more opaque structure, clad in precisely detailed acid-etched low-iron glass. Research indicates that people respond most positively to detail at this scale.
Moving from pure architectural expression to building performance, this year’s winners demonstrate impressive levels of achievement, for example in improved standards, increased air-tightness and construction logic.
Although they rely on established products, these technological advances are driven not simply by wonder-materials, but also by developments in digital design, ambitious legislation, quality assurance procedures and examples set by pioneers like Foster and Grimshaw. The technology used in projects such as Glenn Howells Architects’ Triangle in Swindon impresses not just at the level of metrics, but also because their high performance standards and the way they are achieved are themselves expressive and part of their character.
15 years ago, many of these projects would have ended up in dreary, biscuit-coloured brickwork in response to pressure from sceptical Design and Build contractors. Now, many of these contractors are working with architects to achieve ambitions targets in the use of off-site fabrication and the quality of envelope design, enabling a healthy pluralism in tectonic facade expression.
- Sapa Building System is a world leader in aluminium profiles, building systems and heat transfer strips. www.sapabuildingsystems.co.uk