The external envelope is where most users, and non-users, first interact with a building. When people use the term architecture, it’s fair to say they normally mean what a building looks like, externally. So the external envelope in terms of its materials, detailing and crucially, the resulting overall form which combines those with the structural elements, is perhaps the truest location of architecture as we know it.
This is why decisions on the envelope are so important, for stakeholders but also for the ongoing reputation and popularity of a building. The coming together of elements such as timber, metal cladding, brick and glass is often the recipe for the particular character of a building, beyond merely its shape. After all, many buildings tend to be nondescript rectangular objects externally, with their personalities emerging only once the cladding is added.
While issues such as energy efficiency and safety (with Grenfell Tower being the only too glaring recent example) being paramount to get right first for architects, other considerations must also be borne in mind when it comes to exteriors. The new ETFE-clad American embassy in Nine Elms has been lambasted by Donald Trump, although whether or not this was firstly, a reason to like it, or secondly, part of a ruse to not visit a hostile UK, is hard to say. However it appears that it’s the site that offends him more than architect KieranTimberlake’s unusual elevations of repetitious yet sculptural transparent forms.
This scheme, like the projects featured in our supplement, illustrates just how much the treatment of a building’s exterior can transform not only its fortunes, but those of its surroundings. On page 16, we see how a university halls of residence in a prestigious part of London has been transformed using carefully-designed brick cladding, mounted on precast panels in a way that you ‘can’t see the join’.
And on page 20 we visit Canterbury in Kent to hear how architect Penoyre & Prasad combined an inversion of form in a new library extension’s exterior with a judicious use of materials. The result cleverly helps the building blend with, and enhance, its brutalist predecessor.
James Parker
Editor