Nine in corten

A row of nine new houses in a south west London street emulates aspects of its Victorian terraces – but adds some contemporary twists, most obviously in the design’s copious use of corten steel. Roseanne Field reports

The houses that line Revelstoke Road in Wandsworth, south west London are fairly unremarkable – a row of standard Victorian terraces running along both sides. That is, until you reach the eastern end of the road, where Architecture Initiative’s development of nine adjoining houses, enlivened by corten steel cladding, puts a modern spin on this traditional style of home. The houses have been carefully designed to play on the Victorian vernacular that suburban London has in abundance. The practice worked on the project with ‘boutique’ project management company Style and Space, who design and build homes across the capital. Both companies were drawing from their experiences on a previous project they’d worked on together – a development of eight residential units and a business premises on Pirbright Road, also in Wandsworth. “That project was a similar thing,” explains Craig Shanley, associate at Architecture Initiative. “We basically maximised the available development potential of that site, while being sensitive.” The Revelstoke Road site was previously home to a redundant carpet warehouse and some hardstanding. Style and Space were unsure what the site would be suitable for, so rather than coming to the practice with a number of units in mind, they instead “asked us to do feasibility on it and look at what could be available on the site,” explains Shanley. Although to some the small site might have been limiting, for Architecture Initiative it provided an opportunity to reimagine the conventional housing stock on offer in London. This would include a somewhat unconventional approach to materials.

Innovating density

Housing – and in particular housing in London – is indisputably a hot topic. London boroughs and local authorities are being encouraged to support as much residential development as possible, and so gaining planning permission was unlikely to be a major obstacle. The team also benefitted from the fact that the site was redundant, and the council wished to improve it. “It wasn’t benefitting the area,” says Shanley. “From historical research we knew there was a terrace there that had been demolished at some point so we were basically reinstating the street.” In fact, the practice’s plans were welcomed with open arms. “It got recommended at the committee meeting,” Shanley explains. Councillor and planning committee chair Sarah McDermott was even quoted as saying: “This scheme is exactly the sort of development Wandsworth Borough Council should be encouraging.” “It’s quite rare to have that,” admits Shanley. “They thought it was an innovative approach and they liked the relationship to the Victorian housing and the contemporary material.” The design of the houses, which were all for private sale, took its inspiration from the surrounding properties. However, it’s Architecture Initiative’s belief that Victorian houses make poor use of the available space. The practice’s aim, therefore, was to examine how they could much better utilise the site, without losing valuable living space. “If you took a typical terraced house along that street, they’re not very efficient,” Shanley explains. “So what we were looking at doing was intensifying the use and densifying that suburban area to allow for more residential homes in that same format.” As intended, the nine homes they fitted onto the site utilise the space far more than traditional homes would have done. “If you took the same plot width along Revelstoke Road there’s only three or four homes,” Shanley says. Yet surprisingly, the new homes are “actually really large compared to the London Plan guidelines,” he explains. “They’re oversized.” The nine units comprise five duplexes across the basement and ground floor levels, while four single-storey flats occupy the first and second floors. All nine dwellings have access to inset balconies and terraces. “They get quite generous external spaces,” says Shanley. The duplexes’ bedrooms are located on the basement level – a tactical decision, he explains, due to their reduced need for natural light. “It’s the inverse of the traditional way of entering and going up to the bedrooms,” he says. These bedrooms also benefit from access to a light well terrace area. On the ground floor, the kitchens are in the bay at the front, which as Shanley says, “mirrors the Victorian arrangement.” An open plan layout means this connects with a large living/dining area at the back, which leads out to a higher terrace area. The flats above stretch across the width of the building, with two occupying three bays and the others occupying two. The bedrooms sit at both the front and back on one side of the flats, while the kitchen/living/dining area occupies the other and “replicates almost exactly what’s happening on the ground floor,” explains Shanley.

Getting the look right

The designers’ challenge was creating these innovative spaces while still providing something harmonious to the existing street. “We took some datums across the site,” says Shanley. “Continuing the urban grain along the street defined the front line.” They also stuck to the same line along the back, and looked at the width of the bay windows along the rest of the road. “If you took those as a jelly mould, essentially those were the principles we were looking at – keeping the street frontage but trying to activate it a bit more,” Shanley explains. “The bays themselves relate directly to the Victorian bays but inside the space is a lot more generous.” The only alteration to this arrangement was where a “cutback” was made to the first and second floors next to the surgery which sits at the eastern end of the new row of houses, so as not to block windows. The decision to clad the extended bays in corten steel was largely inspired by the range of colours found in the local built environment. “The materiality in the area is quite a blend,” Shanley says. “They’re largely red brick, but what’s unusual is they also have stock brick and quite a lot of white render.” As well as replicating this blend of reds and whites, the architects had also decided they wanted to emphasise the bays by using a different material, and so as Shanley says, with the stock brick being used elsewhere, “corten seemed to be quite a nice way of doing that blend”. They also took inspiration for this from a church across the road which largely comprised stock brick, but with a prominent bay. “We wanted to make it a contemporary form,” Shanley says. “We wanted it to look like one material was wrapping around, almost like a separate skin, and corten met those requirements.” The practice is fond of using corten, as shown on various projects in its portfolio. “We’d just used it on a primary school so we were familiar with the material,” says Shanley. “It was something we were used to in the office.” Although in the end the corten covers the front of the bays and continues up to the roof, the form of the frontages could have looked distinctly different, explains Shanley. “We looked at various options for using it, and how it interacted with the brick”. At one point, they considered wrapping the whole of the bays in the corten but the idea had to be abandoned at it was going to make the building too heavy, plus, as Shanley says, “it just seemed a bit dense. It essentially became a skin, because it helped break up the bigger mass of the brick.” Shanley also believes the balance between the amount of corten compared to the stock brick matches the ratio of red to white on the rest of the area’s buildings. Additionally, the surgery next door is finished in stock brick, so “the lighter brick seemed more appropriate,” he says. Like the decision to use corten itself, the seemingly unusual decision to take the material right up onto the roof is not a novelty for Architecture Initiative. “There’s a precedent we’ve used which does the same thing, where it’s just one cast piece of metal,” Shanley explains. However, carrying it right up did mean the pitch of the roof was dictated by the metal: “It’s got warranties for how deep you can go because of wind,” says Shanley. The distinct weathered appearance of corten caused some confusion when the sheets first arrived on site. “A couple of people were telling the builders to ‘paint it quick because it was rusting!’,” Shanley recalls. Although the metal’s appearance changes over time – when first oxidised it takes on a light orange colour – he explains that just before it arrived on site, it was treated to allow the weathering to stop at a certain point. It will therefore deepen to – and maintain – a darker orange colour, tying into the red bricks and tiles found in the locality.

Daylight

Although the project fitted nine units into a relatively tight site, getting enough daylight into them proved to be no problem, and was something the architects were particularly conscious of, having dealt with what Shanley says were “concerns” about daylighting on the Pirbright Road scheme. The way the duplexes and flats have been designed means plenty of windows – both north and south facing – along with the internal balconies and basement light wells – “flood” the living spaces with daylight. In fact, “the challenge wasn’t necessarily getting light in,” explains Shanley. “It was making sure you didn’t impact on other people’s light.” Offsetting this potential side-effect of achieving a space-efficient density level was one of the main concerns to be addressed at the planning stage. It was a key reason for ensuring the footprint followed the same lines as the rest of the street (other than the required alteration for the surgery), and for keeping the balconies inside that curtilage.

The future of housing

The approach Architecture Initiative took for this site is something Shanley thinks London could do with more of, to address the acute need for housing. “As a company, we believe in densification,” he says. They recently worked on a report which demonstrated that when looking at a traditional terraced house, a hectare of space will fit an average of 50 dwellings. However, by densifying the units as they have with this project, up to 220 dwellings can be fit into a hectare. In particular, the practice believes this is important in the suburban areas of the city – anywhere with residential developments of no more than four or five storeys. “This is basically what we were looking at with Revelstoke Road,” Shanley says. “There’s got to be a way of increasing the amount of homes available and so this was a way of doing it, making something fit in with the streetscape, but increasing density.”