We built the house on a garden site that we bought at auction. It was a huge risk when we bought the piece of land back in 2000 with no planning permission and no services. Rather romantically, perhaps, the garden was next to a pickle works that is now, sadly, a paint spray shop. It was a long back garden to a handsome Georgian building, so we had to get all kinds of planning approvals.

My wife, Rachel, and I jointly bought this site, and she had an interest all along in doing a house. I have to give her enormous credit. It can be hugely stressful building a house, and it is probably easier for me because I’m in the business. It’s a slow process, and you do it on a shoestring.

The whole idea of a timber frame means that you can build quickly and move into a flexible space, rather like a barn or loft, at minimum cost and then fit it out or change it as you live in it. Though the work does slow down when you move in. It’s a bit of an admission for an architect, but there’s no doubt that once you are in a place—–no matter how good your planning—–you are not fully aware of how that tree next door, for instance, might relate to the space or affect the light. When you move in you can refine things, but you risk driving your family mad in the process.

As a family we tend to gravitate to the living room and kitchen—–that’s the focus of family life. The children tend to do their homework and drawing on the kitchen island or the dining table and watch television downstairs.

The Corian kitchen island unit acts as a real hub. A lot of people are surprised to find a television tucked away under the worktop, which we can watch from the sofa. It doesn’t dominate the room, though. The kids sit at the island for breakfast and other meals, and when people come they end up sitting there and talking while we are cooking. It works well. Then we have a more formal dining table looking out over the garden.

On the ground floor, we have a shift in floor level between the entrance area and the rest of the living area, which was completely to do with the difference in level between the street and garden. We wanted high ceilings and a double-height space in the kitchen area, which is to the side of the main living zone, with a mezzanine and an internal balcony above. The change in level allowed us to get the ten-foot-high ceilings, and be able to walk down into the main living space.

Downstairs is a flexible, open plan, while upstairs is more cellular. On the second floor, we can use sliding doors to section off the guest room and a small en suite bathroom. It’s a luxury in London having a spare bedroom, but when my older daughters—–Katie and Lois—–come to stay, it’s good for them to have that sense of privacy.

We maximized every bit of space by creating a third floor up in the eaves. When we first moved in, the girls—–Mae, 6, Jodie, 8, and Ruby, 10—–had a big, open, attic dormitory up there with rows of beds. More recently we divided that floor up into a study and then three separate bedrooms, each with a normal bed and a bunk bed tucked in up by the ceiling, which are great for sleepovers. There’s definitely a kids’ zone up in the attic and an adult zone on the second floor.

On the whole the house has some of the feel of a barn or a warehouse, but also of the Californian Case Study houses, like the Eames House. Japan-ese domestic architecture is also something we really admire. The wood factor fits in with that, but this is not a highly detailed house—–it’s very simple. You do get that kind of modular sense here which you get in some Japanese houses, plus the minimalism—–being able to put all the clutter into the banks of storage that we have.

In the summer you can extend the main living space by opening out into the garden. The buttress zone idea, with storage running across the side wall of the house, carries out into the garden where there is a big storage cupboard with a huge sliding door and a built-in sofa bench. It screens out the factory beyond.

Rachel takes most of the credit for the water pond. It was her idea to create this bridgelike feeling as you pass into the yard. There’s that Japanese flavor again and a few fish. In the summer the garden really adds a whole new dimension to the house, becoming an outside room.

Before this house I built another timber-framed house in Highbury for the family. My father, who is a retired architect, built our house in Hertfordshire, where I was born and grew up. It’s in my blood. I think I’ve got three houses in me, and—–having finished this one—–I’ve done two. One to go.