A deft piece of urban surgery renovates and adds to a patchwork Swiss housing block
In order to survive in a harsh world, young architects often turn to friends and family when looking for work. And Basel-based firm HHF – founded in 2003 by Tilo Herlach (1972), Simon Hartmann (1974) and Simon Frommenwiler (1972) – was no exception, carrying out small renovations on a group of four properties owned by Hartmann’s family in Basel’s Sankt Johann district. Back in the 19th century, the land in question had been Hartmann’s great great great grandfather’s farm, which the family had redeveloped with rental housing at the turn of the 20th. When, after Hartmann’s grandmother died, some of the inheritors decided to sell, Hartmann persuaded his father to buy up the majority stake and let HHF restructure the ensemble. Little did they know, when they began the operation in 2006, that they would be embarking on a nine-year-long adventure which was only finally completed last year.
Among Hartmann’s reasons for encouraging his father to invest was that Sankt Johann was about to undergo major change. Not only had chemical giant Novartis begun developing land right next to the Hartmann-family properties for what would become its vast research campus, but the city had also decided to construct a motorway tunnel under nearby Voltastrasse, which, when it opened in 2008, transformed the thoroughfare from a traffic-choked highway into a green and pleasant boulevard with new buildings rising along its length. As Hartmann recalls, he had a hard time convincing people that Sankt Johann was about to mutate from a working-class neighbourhood of low-income rentals into a highly desirable extension of the city centre, but his prescience would prove spot on.
‘Indeed the whole operation, with its patchwork, collage, bricolage and stitching together of the old and the new is atypical in the Swiss context’
The four Hartmann-family buildings form an ensemble which turns a street corner: nos. 9 and 11 Lichtstrasse (the corner building), and nos. 1 and 3 Kraftstrasse. Prior to HHF’s intervention they were in relatively poor condition, Lichtstrasse 9 being without bathrooms, its residents having to use lavatories on the stairs and bathing facilities in the cellar of the building across the courtyard. Of the four, Kraftstrasse 3 was in the best shape and only needed reconditioning. But, because of the position of its staircase, Lichtstrasse 9 was impossible to remodel to bring its poky apartments up to modern sizes. So HHF persuaded Hartmann’s father that it had to go. ‘By doing that,’ Hartmann explains, ‘we could not only solve the problem of this one building but also do something that generated a new condition for the other two buildings on the corner site.’
What HHF undertook at Lichtstrasse was a deft piece of urban surgery. Why have three entrances and three staircases when you could have just one of each and gain lots of useful space in the process? The entrance to Kraftstrasse 1 was enlarged to serve all three buildings, freeing up ground-floor space in Lichtstrasse 9 and 11 for a spacious restaurant. Meanwhile, a new common staircase was built in the courtyard, allowing those in Lichtstrasse 11 and Kraftstrasse 1 to be removed and the space they occupied recovered for accommodation. And, in its rebuilt form, Lichtstrasse 9 wrapped around the new staircase and the rear of Kraftstrasse 1, occupying more space and joining the ensemble together. For what HHF had realized was that while the apartments in Lichtstrasse 11 were fairly spacious, those in Kraftstrasse 1 were densely packed with small rooms. By joining Lichtstrasse 9 to Kraftstrasse 1, there was the possibility of having very big apartments, with bedrooms and other cell-like rooms in the Kraftstrasse part and large open-plan living spaces in Lichtstrasse 9. This also made perfect commercial sense, since the operation was being financed by the sale of the large new apartments made possible by the rebuilding of Lichtstrasse 9, which were of course the most valuable (those in Kraftstrasse 3 and Lichtstrasse 11 remained rental properties). Moreover, HHF made sure that these large apartments had two separate entrances – one to the Lichtstrasse part and one to the Kraftstrasse building – so that they could be divided in two again if necessary (which one buyer has chosen to do, occupying the Lichtstrasse building and renting out the Kraftstrasse part).
‘Little did HHF know that they would be embarking on a nine-year-long adventure which was only finally completed last year’
Some readers may be thinking, ‘Gentrification!’, but, as Hartmann points out, it wasn’t quite that simple. A third of the original occupants chose to remain, since they were at a stage in their lives where they would have moved away to something bigger and better, but the renovation allowed them to stay put (and its execution in phases meant they could be decanted from one building to another during the process). Furthermore, HHF’s intervention resulted in a mix of typologies, with very large apartments (up to 190 sqm) and some much smaller ones (60 sqm), as well as a mix of renters and owners. So low-, middle- and high-income households are all present in the same development, which is not usually the case in pure gentrification schemes (moreover, the rents in Kraftstrasse 3 stayed the same as before the renovation). And if profit were the sole motive, a lot more money could have been made by demolishing all four buildings and constructing a denser replacement. But HHF felt strongly that the neighbourhood’s character would be irrevocably and detrimentally altered if the entire ensemble came down.
Where the rebuilt Lichtstrasse 9 is concerned, the architects opted for pared-down minimalism, with interiors entirely in exposed grey concrete. The floor plates were sold empty, each buyer choosing their own layout (plumbing was provided in four different locations on each floor to allow flexibility for the positioning of kitchens and bathrooms), a customization process that gave rise to very different results. Hartmann himself took the top-floor duplex, for example, which the office designed for him in a relaxed mode of stylish bricolage; the second-floor owner went for a cool, classic, mid-century-modern feel; while the first-floor buyer opted to plaster over the concrete for a much more traditional look. Where the street façade was concerned, HHF wanted to respond to the building’s setting on a sizeable green, and aimed for a sort of treehouse effect with non-orthogonal balconies projecting out from the street line (partly to catch the attention of pedestrians arriving from the Novartis campus). The architects also wanted the façade to be both open and veiled, and designed a system of dark-green railing bars inspired by bamboo scaffolding they had seen in China (to further the forest-canopy effect, artist Erik Steinbrecher cast four of the taller bars as sapling trunks). At the rear, similar bars were used, only in aluminium, combined at times with corrugated polycarbonate roofing to produce a sort of DIY-assemblage effect, an approach underlined by HHF’s having asked the manufacturer to get young apprentices to make the aluminium bars, ‘so as to have a less refined finish and unequal appearance’. A similar approach was adopted when renovating the interiors of the old buildings - ‘Whatever could be kept, we kept. We just patched damaged parts with modern materials’ - which, in a country where anything old looks like it was made yesterday, could almost be considered radical.
‘What HHF undertook at Lichtstrasse was a deft piece of urban surgery’
Indeed the whole operation, with its patchwork, collage, bricolage and stitching together of the old and the new is atypical in the Swiss context. And in fact it’s atypical of the way almost all architecture is made, since there is rarely the opportunity of having so much time to get to know a given situation in depth. It’s a process that is less about design per se than about asking the right questions and finding the right solutions. It’s also an example of what happens when the architect takes on the roles of both maître d’ouvrage and maître d’œuvre - defining the programme (and to a certain extent the budget) as well as undertaking design and construction. This included the decision to have an upmarket restaurant on the ground floor (Hartmann’s father had to be persuaded, since Swiss banks mark down a lower value for residential buildings with restaurants) and searching for the right person to take it on (everyone told them it wasn’t a commercially viable location, but HHF were convinced, when smoking was banned on the Novartis campus, that it would be a roaring success. They were right). Costs rose unexpectedly during the building process when it was discovered that the existing buildings had been put up on the cheap and needed significant work on the attics and foundations to bring them up to modern norms - as Hartmann remarked, ‘It was almost a luxury to preserve the old’ (or, as his builder put it, ‘What your great great grandfather skimped on in 1900 you’re having to pay for now’). But they managed to keep the total to within the price of a new build, the entire operation (with the exception of the Kraftstrasse 3 refurbishment) coming in at CHF 6.5 million. Indeed everyone seems to have been a winner on this project except, to a certain extent, HHF themselves, since they say they lost money on the job. But asked if, with hindsight, they would do it again, they answer with a resounding ‘Yes!’