"We chose to pour the concrete in stages, so it could be manipulated every step of the way. The formwork of each stage was just 4ft high, and was wrapped in shiny Formica, which imparted a great sheen to the concrete. Concrete can appear as a very cold, forbidding surface, but these walls have a blue-black tint and are hyper smooth and inviting to touch.
"Once the concrete was poured into each section, I introduced streaks of amber-colored concrete that could be pushed down into the walls. For added visual interest at the front of the house, the upper concrete walls were striated to resemble geological strata bands."
Cheng says the resulting walls, which are 14in thick, with 3in of foam insulation, convey a strong sense of substance and permanence. And because they make up the entire wall, there is no need for wallcoverings or veneers.
"We introduced porthole windows to the walls in irregular positions, and added an elliptical-shaped window to the upper level. These apertures highlight the thickness of the concrete and you get a strong sense of the real mass of the house – it is almost castle like. And it has a solidity that simply cannot be replicated in a house built from wood."
In contrast, a lightweight, translucent canopy defines the entry, which is through a large zinc and brass pivot door.
The concrete side wall extends right into the house, forging a connection between inside and out, and helping to screen the living area from view. An outdoor-indoor fishpond beside the entry, flows beneath the wall to the inside of the house.
To relieve the austerity of the concrete walls and flooring, another wall beside the entry is covered in Japanese plaster in a rusty brick tone, with a glowing, illuminated yellow shelving niche.
"It was important to keep the interior warm and inviting, and this applied to texture as well as color," says Cheng. "We were constantly looking for materials that would have a tactile finish, to contrast the very smooth concrete."