What can you do when building regulations say that you can’t build higher than a single-story home on your property? Then you build an underground house, of course.
The home of architects Deborah Saunt and David Hills of DSDHA Limited is located in Clapham Old Town, in the heart of a Conservation Area in South London.
It stands two miles from Parliament Square and London’s West End. It used to be the backyard of an existing 19th-century home and was an overgrown garden of sycamores and ivy.
Surrounded by 23 other households, buildings in the conservation area have a height limit, so the architects decided to be creative with their new home. The project began in 2007 with the purchase of an old house with a large overgrown garden.
Saunt and Hills also decided to use their home to test their ideas on sustainability and how homes can be built close to city centers without violating conservation restrictions and encroaching on other private gardens. The building began in 2010 and the project was completed in 2014.
The sensitive setting prompted a design that blends the house into the background. Saunt declared, “The challenges of designing and building in a conservation area are primarily to do with how you can build something new, whilst not having a negative impact on the character of the setting.”
“You have to, first of all, understand the setting from a conservation point of view, and then be able to argue that the contemporary element you are bringing will add to the history of the area over time, rather than distract from the inherent beauty of the place.”
The pair decided to sink the 135-square-meter house down into the landscape, to reduce its height and create some privacy.
They named the project the Covert House since one floor of the home would be above ground and one sunken underneath.
They started with a concrete box to create a secure and simple structure for an underground house. Hills shared, “We dug a big hole to build the house in. It’s just a square box. That’s also cheaper.
Every time you have to push in and out, then you’re building really complicated shuttering. So when you go down, the simpler you can make it, the better.”
To accommodate as much daylight as possible into the underground house, they dug sunken courtyards around the home to act as lightwells for the downstairs. These draw daylight into the three subterranean bedrooms.
Saunt explained, “As designers, we always hope to set new standards, even in the dense centers of our cities. So we knew early on that it was crucial to make the rooms feel open and unconfined, and that to achieve this we would like to create proper courtyard spaces.”
The couple built the ceilings as high as possible to avoid making the underground house feel like a bunker. A white cast-concrete staircase with resin flooring provides access between the two floors.
Saunt said, “The white stair almost becomes a personality in the room. It couldn’t be too dumb nor too grand, but needed a human scale so that it seamlessly transitions between the two levels.”
The upper level accommodates the living, dining, and kitchen areas. These open out to another terrace that overlooks the courtyard below.
“We didn’t want the lower floor to feel substandard compared to the upper floor and wanted the house to feel balanced and always connected to nature, so we worked hard to anchor a sense of space and expansiveness via the use of courtyards,” added Saunt.
The artistic pair used a muted palette for the furnishings and fittings to prevent spaces from appearing cluttered.
The kitchen is dominated by white cupboards and polished concrete surfaces, while the living room has wooden pieces with grey or red upholstery.
Skylights and strategically placed windows protect the home’s privacy but still allowed natural light to come into the upper part of the house.
They painted other external surfaces white, but exposed the building’s concrete structure inside, thus reversing the approach usually taken for concrete residences, which are often plastered white inside.
“We juxtapose concrete against whiteness, be it in the form of natural light, controlled and carefully calibrated to bring animation and delight deep into the plan, or represented though the use of white as a finish. The resultant design is precise and sculpted; materially rich yet calm as a place in which to live,” said Saunt.
The architects were careful to prevent the underground house from overpowering its setting, so they used mirrors as cladding to reflect the trees and surrounding garden and help camouflage the home.
They also decided to replicate that environment with a green roof designed with drought-tolerant sedum plants. These require only a very thin buildup and promote wildlife. They also planted new trees, like mulberry, around the home.
Sinking part of the building helps stabilize the temperature in the underground house, but a heat recovery system using an air-sourced heat pump provides a sustainable heating source. Rooftop solar thermal panels heat the home’s water.
The home is a beautiful example of how sustainable and modern architectural design can blend into a traditional conservative setting.
Saunt shared, “The Covert House hopes to demonstrate how uncompromisingly modern design can be beautiful. It is quietly radical on a number of levels but, at the same time, a well-mannered neighbor. For us, we look forward to when the 12 new trees we planted will be fully grown and the house will essentially blur and disappear into the background.” Covert House was recognized with a RIBA London Award in 2016.
See the beautiful underground house in the video below:
To watch more videos on extraordinary homes be sure to follow Kirsten Dirksen YouTube channel.