The building is partially sunken to preserve and emphasise a long view from the street across the back gardens of neighbouring buildings, an ambition that meshed neatly with the need to remove an extensive infestation of Japanese Knotweed which had established itself on the site.
Despite being overrun with this troublesome perennial plant, Jack was not deterred as he explains: “I had been looking for plots for a while and this came up at auction. I very much liked the street when I visited the site. The site was undervalued due to blight caused by a number of failed, inappropriate applications by previous owners and the Japanese Knotweed which put potential buyers off.”
After six months waiting for planning permission, consent was received and work could commence. The first hurdle came in the form of removing the Japanese Knotweed. “This made the excavation process more complex than it otherwise would’ve been,” says Jack. “I had planned for the project to take 12 months, but in the end it took 14 months from breaking ground to practical completion.”
Spiral House is conceived as one continuous wall, which wraps the boundary before spiralling into the centre of the site to form habitable spaces. The 90m² gross internal floor area has three distinct zones: living, dining and sleeping, with a moveable internal wall allowing flexibility with the way the spaces are divided. Jack comments: “I wanted the building to work as a one bedroom house most of the time, with the ability to create a second bedroom at short notice when grown kids and other guests came to stay.”
The roof of Spiral House is planted to give neighbours – with an elevated view of the house – a horticultural outlook appropriate to the site’s historic use as a garden, whilst revealing the continuity of the spiral wall.
The 94m² of external space includes shallow concrete steps, graduating from street level to the house entrance, and a sheltered, central courtyard garden. A folding glazed wall in-fills the brick spiral, bisecting the continuous concrete floor that connects the internal and external space, and disrupting the boundary between inside and out. This is further emphasised by an 11m-long rooflight along the northern edge of the building, which frames an uninterrupted sky view.
Helping to create the impression of more space, glazing became integral to the design. The high specification of this material, however, meant to project’s budget was forfeited. Jack comments: “The budget went slightly over because the glazing became a crucial part of the architecture and I ended up choosing systems that were more expensive than originally intended – particularly the bi-fold doors which have a reduced frame thickness.”
Although relating to the surrounding Victorian neighbourhood with its red brick and white palette, Spiral House suggests uniqueness through its Roman style of brickwork. The Spiral House wall is built from distinctive, long, thin Linea 3016 bricks, sourced in Belgium from prestigious family manufacturer Vande Moortel.
Frameless windows sit flush with the outer face of the walls, their crisp outline and smooth surface contrasting with the rough texture of the brick.
The low energy house has a highly insulated building envelope, and excellent daylighting. Sunlight heats the concrete floors and exposed brick walls, allowing their thermal mass to store heat and regulate internal temperatures.
The building is naturally ventilated: a temperature differential is created across the north wall by its partial exposure to sunlight through the rooflight, drawing fresh, cooling air through the space in hot weather. Low energy LED light fittings are used throughout.
The architecture unlocks the latent potential of this previously overlooked plot, exemplifying an astute sensitivity to context and an innovative and exploratory approach to materials. “It gives such a sense of calm in a crowded city,” enthuses Jack. The local community are impressed too. “They seem pleased, especially the neighbours immediately opposite. The building was open for the Open House weekend – many local people came and were very positive.”
Even after complex excavation work at the beginning and pressures on budget, Jack regards the project as being an exciting and rewarding experience – a feeling many self-builders call into question when in the thick of their own build. Offering some helpful advice to fellow self-builders, Jack comments: “Don’t lose sight of what you are trying to achieve. There are moments during the build when things can seem overwhelming and it is tempting to take decisions that offer an easier ride. It is worth thinking twice before taking them, as they could result in compromises you might later regret.”