A Subterranean Self Build

At the end of a sedate row of traditional four storey Victorian terraced houses in Kensington stands – or rather squats – the unique home of David and Jaruska Snowden. Formerly the site of two lock-up garages, the tight corner plot was excavated so that two thirds of the new house could be sunk down to form a semi-underground dwelling, to meet strict planning restrictions in this Conservation Area.

The resulting two storey house may have been conceived as a compromise, but nothing about this contemporary building is half-hearted. Outside, a pollarded plane tree in the street casts gnarled shadows across the unexpected white box and people regularly stop to stare at the funky low-level structure, unaware of what lies beneath.

Far from keeping up with the Joneses, David and Jaruska have built a house which is a fraction of the height of the other Victorian buildings in their road. The planners stipulated that the Snowdens’ new house should be no more visible from street level than the existing garages — projecting less than three metres above ground level.

Inside, the clean lines and white reflective surfaces – coupled with a huge amount of glass in the walls and ceilings – ensure that this bright modern home is more glittering jewel than dingy subterranean cave.

Building underground involved excavating the entire site to form a basement level, constructed on piled foundations with reinforced concrete inner walls. The floors, roof and walls of this concrete-framed structure act as a thermal store, and sinking so much of the building below ground minimises heat loss and results in a reduction of energy bills of around 15%. Another benefit of underground living is the soundproofing, which ensures that the Snowdens’ home is a peaceful haven in its urban setting.

The couple, who have been married for 30 years, are no strangers to unusual homes. “In our last house we did the same thing and excavated down on the site of some old garages in Islington,” explains David, an ex-art student and semi-retired restaurateur. “We decided to move to a different area, but wanted a similar style of home.”

Despite the fact that there had already been a number of failed planning applications to develop the land the Snowdens purchased, they engaged the same architect as before — their long-term friend Alan Crawford of Crawford Partnership. They tweaked the design slightly and began the long process of gaining planning permission for a modern structure.

“We still wanted to position the living spaces upstairs, with the bedrooms downstairs,” says Czechborn Jaruska, “but in our previous house the internal courtyard was covered, and we decided that we’d prefer to leave this area open and actually feel a breeze when we open the bedroom windows. We have several small fountains down there, and on a warm day you can sit outside on the slate patio in privacy.”

Open lightwells have been punched through in the front and rear garden areas, and below-ground bedrooms face onto these courtyards through fullheight sliding glass doors, which open directly onto the garden spaces.

Upstairs, at ground level, the open plan living/dining/kitchen is punctuated by glazed walls to the front and rear, which overlook small-walled gardens.

Garden designer Paul Cooper worked with David to devise the stylised steel entrance gates, which, together with the aluminium blinds, create an atmosphere of seclusion.

“We have great views out from the living room,” says David. “Every day we can watch the Household Cavalry, who parade past on horseback.”

Somewhat refreshingly, the furniture in this living space is an eclectic fusion of predominantly antique items with a strong Oriental flavour.

“We already owned and loved most of the furniture, and didn’t feel the need to get rid of our belongings,” says Yorkshireman David. “Anyway, buying everything new can look rather contrived.”

The compact kitchen is tucked into one corner, with a clutter-free stainless steel worktop set beneath the long horizontal window. Overhead glazing provides additional light and ventilation, and a fullheight wall of storage opens to reveal the dishwasher, two ovens, fridge and hob hidden inside.

“You do have to be quite tidy living like this, but we have never been hoarders,” says Jaruska. “Clever design means that items such as dirty dishes are hidden away from the main living area, which is one reason we incorporated the oak wall in the kitchen. We wanted the units to look more like furniture.”

Part of the ground floor roof has a large glazed slot cut into the concrete slab to allow for a staircase to be installed in the future, and the couple have submitted a further planning application to build an all-glass box up at first floor level, which will hopefully become an additional living space. “The simpler the design the better,” concludes David.

Subterranean Homes

There are several ways of building subterranean homes, including: ‘cut and cover’, whereby homes are assembled from precast concrete pipes and containers before being buried; PSP (post, shoring and polyethylene), where the house is built by excavating the ground, sinking in posts, placing shoring (boards) between the posts and the earth before placing polyethylene plastic sheets (to waterproof) behind the shoring; and ‘atrium’ homes, where rooms are built below ground around a sunken courtyard to let light in, much as the Snowdens have done. Despite requiring an extremely well thought out design in order to work well, underground homes have many advantages, including being very energy efficient, benefitting from geothermal mass and heat exchange, so staying cool in the summer and warm in the winter, saving around 80% in energy costs. Underground homes are also very well insulated from noise — a particular advantage in towns.

Further reading:

• An Urban Self Build on a Small Plot
• A Split Level Self build
• Site Specific Solutions For Problem Plots