Zinc is one of today’s most versatile building materials. Originally used for roofing, it is recognized by many architects for its durability and green qualities, being 100% recyclable, requiring little energy to manufacture compared with other metals, ductile and maintenance free. VMZinc, a trademark of the Umicore Group, from the Vieille Montagne near Liège in Belgium, has been mined there since 1837, but it is not just the grey associated with roofs: since 2005 the firm has offered a range of coloured, preweathered products that are must-haves for many contexts.
In London, VMZinc’s versatile material assets regularly appear to be a favourite of leading architects. Bennetts Associates’ Mint Hotel Tower of London – with 583 compact rooms the biggest hotel to be built in London for 35 years (it was completed in December 2010) – uses zinc as part of a integrated palette of materials. It appears on the façade, on the lift tower, on window surrounds and is used for a sequence of semi-perforated shutters on the eleventh floor. Here there is a skyline bar – the SkyLounge - accommodating up to 300 people with a roof garden with 360 degree views of the Heron Tower and the other icons across London’s financial distrct – Lloyds, the Gherkin, the Tower of London, St Pauls and the former Port of London Authority building. A large green wall at the top of the atrium is also visible at the level. While the massing of the building is in keeping with its neighbours in terms of height and materials, the SkyLounge is treated as a distinct element sitting discreetly above the adjacent roofs, and the zinc shutters play a key role in creating this sense of material differentiation.
‘It’s a nice material, low maintenance, with a high recycled content. I like the look of it’, says co-founder Rab Bennetts. ‘We tried to limit the materials to concrete (the structure is pre-cast concrete), stone and zinc. The building sits on a tight island site between Fenchurch Street Station to the north and conservation areas to the south and west. The urban grain in this district is tight and dense and most blocks of buildings are defined by the medieval streets as they fan out from one of the City of London’s original gates. Well over half the building was pre-fabricated and lifted into position on site, an efficient method in such a street, and the hotel has its own underground parking. Its entrance on the south façade asserts a bold scale of entrance heralded by stout in situ concrete columns.
The Hotel’s lobby opens up as a gigantic space, with an atrium extending from ground to roof level, revealing the green wall. A bar, restaurant, meeting and conference facilities are located on the ground and first floors below the guest rooms and suites. All the guest and function rooms have floor to ceiling windows allowing plenty of light in. The SkyLounge is where the local workers seem to most enjoy going for informal meetings: ‘It’s an ideal point to perch up above everything’, says Bennetts.
A recent housing scheme using VMZinc is the Laycock Street residential development in Islington, designed by Brady Mallalieu, which incorporates a purpose built medical centre for 12 doctors. The architects have arranged a mix of townhouses, maisonettes and flats around a shared courtyard. They employ a rich palette of materials including zinc cladding and copper, creating a stimulating and varied set of elevations to the 68 new homes, which include social housing. Significantly, the social housing is not differentiated in appearance to the rest of the units, which is less common in the UK, and enjoy the same kind of textured mix of materials to the others. ‘We wanted the materials to be as low maintenance as possible’, said Angela Brady, co-founder of Brady Mallalieu. The flats have north and south facing windows like Corbusier’s Unité d’Habitation plan, and all of them have balconies. There are ten family houses with four bedroosm facing the one and two bedroom flats. The courtyard has a peaceful air and reminds a little of the work of Dutch architect Herman Hertzberger in the way the design achieves a harmonious social and aesthetic integration.
Internally the flats have a casual play area at the fronts, with a garden area linked to the kitchen, a thoughtful layout. ‘We like to have variety, so they are all a little bit different’, says Brady, but the difference is not qualitative. The overall appearance is consistent, with lots of soft toned green and grey zinc, although the doctors’ surgery has a bare concrete wall. The architects like zinc ‘because it’s a natural material, and it will stay the same colour. It looks good. We use it for most of our bridges’, adds Brady. But as with Lett Road housing, a scheme near the Olympic site in east London by architects Proctor and Matthews, where it has been used on the façade but also for seating in the roof garden, it has a very versatile quality in housing – it spells quality, without being an old-fashioned precious material, ecological values and occupants enjoy the fact that it is stands the test of time, being almost zero maintenance. It is naturally central to the language of 21st century architecture.