When siblings Hugo and Grace McCloud set out to buy their first home, they never imagined that they would come to design and build it themselves. The pair had spent nearly two years searching for something to buy in south London without success, having pooled the money left to them by their late mother to do something together. When they came across a site with a proposal for an end of terrace house on The Modern House and with Hugo having recently qualified as an architect, they decided to make the project their own.

“It definitely had not been on our agenda until we saw the plot,” Grace, a managing editor at The World of Interiors magazine, tells us as we drop in on her, Hugo and Isabel – Hugo’s wife and an illustrator – at the finished ‘House on the End’. “We certainly didn’t go into it thinking we were going to build a house, but with Hugo being an architect, it seemed like a no-brainer.”

Here, in the first of a new series called Checking In, in which we’ll be meeting buyers at their new homes, we return to Crofton Park, three years after we sold them the site, to learn more about the experience of designing, building and living in a terraced house reimagined for contemporary life.

Grace: “It was really by chance that we came to this project. If we had not found this particular plot of land we wouldn’t have had the idea to build rather than buy. It felt like a lovely way to spend the money our mum left us, but also sensible that we do it together.”

Hugo: “I had the skill set to design and manage the build, and with Grace’s design knowledge it was obvious that we would make a good pairing. It was roughly within budget and we thought we could make savings during the construction process, so we bought it.

“It took me a year to get the design in place. I had started dating Issy nine months before we bought, and I would go away, design something and table it to Grace and Issy to get their feedback. It involved them much more in the process and meant that I didn’t get too carried away, as I might have done without a client to keep me in check.”

Grace: “It wasn’t always easy. I suppose you’re always going to have tensions with your clients, but maybe they come to the fore more when you’re working as siblings. There is an honesty between us though, and we actually became quite good at resolving whatever issue there was.”

Hugo: “We had the plot and a set of simple plans as part of the planning permission, but we wanted to make it our own and so we completely redesigned the layout. It hadn’t been conceived initially as a concrete house but we decided to build with fibre-reinforced concrete. Not having rebar, as is traditionally used with concrete, allowed us to achieve certain efficiencies in the layout as well as time on site, the amount of reinforcement needed, and the amount of detailing we had to pay a structural engineer to do. It is quite an innovative material – I believe this is the second house in the UK to be built from of it.

“And then, unlike traditional terraced houses of this scale, we brought the kitchen to the front of the house, because with modern life everything that goes in and out of the house goes through the kitchen.

“The build was programmed to finish in July the following year. Issy and I were planning to get married at the end of August but just before the wedding the house was still not finished. The house had builders and contractors knocking around until the middle of September when we came back from our honeymoon.

“It had always been conceived as a two and a half- to three-bedroom house, but the original plan was Grace and me to live in it. When Issy and I got engaged the design shifted to make it more of a marital home. We made the master bedroom bigger and turned the main bathroom into an en suite.

“It is a very tight site – about 73 square metres – but we’ve built an 110 square metre house on it, over three floors, just through an efficient use of space. And it’s meant that the spaces can be used for many different things: the study could become a nursery for example, and during lockdown we’ve been able to adapt how we used different spaces.”

Isabel: “We were incredibly lucky in that sense. We’ve been able to have our own workspaces separate to the living room and kitchen, which is great because we are not used to working from home. And, with the time we saved by not commuting, it meant we can make the finishing touches to the house.”

Hugo: “There’s a quote that says a well-thought-out construction can be its own decoration and to a degree it’s true here. With the fibre reinforcement, you can only drill into the tie holes, where it’s a softer concrete mix. It actually defines where you can hang pictures or install lights – there’s a framework that runs through the whole building that sets out the design of the interior.”

Grace: “And because it’s quite blank and minimal, the special pieces that you do have, like the John Piper tables or the Eames RAR chair, are given their own space, which works really well.”

Isabel: “The architecture does almost become its own decoration. The interior design was mainly just a case of finding the furniture we wanted and needed, and which complimented the raw materials – there’s almost no paint in the house. A lot of the furniture has been inbuilt, such as the desk in the study, all of which Hugo designed.

“My favourite room is at the top of the house, under the pitched roof. It’s warm and cosy, especially when it rains on the roof-lights. There’s a great view out to the trees and the park, and you can’t see the street so you almost forget that you’re in a big city.”

Grace: “The design of the house is sensitive to the adjacent Victorian terraces on this street, but inside it feels very unlike the other houses. If you look at the front, you wouldn’t be able to tell it’s back-to-front or made from concrete.

“And it’s also been designed to function incredibly efficiently, partly because that was one of the stipulations of our mortgage, though I also don’t know how you could justify making a building from scratch if it didn’t perform well.”

Hugo: “We installed underfloor heating throughout and each room is thermostatically controlled. The design has a SAP rating of 92+, or equivalent to EPC A, which is super energy efficient. There’s no mechanical ventilation or heat recovery, it’s just the airtightness and thermal mass of the concrete. There are typically two people and two dogs who live here and seemingly that’s enough heat to keep the building warm. We haven’t turned the heating on since February.

“I think overall it’s quite a complex design but it achieves a very simple way of living. It was about trying to find efficiencies in the space, with everything being open plan and trying to minimise corridors as much as possible, placing the kitchen at the front of the house or designing a little cubby hole for the dogs under the stairs.”

Grace: “It’s not vast but nothing’s wasted. The rooms don’t feel huge for no reason and everything fits very neatly. We live in every corner of the house – it’s not like there’s some out-of-bounds dining room that we never use.”

Isabel: “We’ve been here for a year now. You get used to life here very quickly – when someone walks into the house for the first time and is blown away by the design, it reminds us how vastly different it is to other homes.

“I can’t really imagine living somewhere different. Certainly as our family develops we might make some alterations but it’s a baby-friendly house.”

Grace: “I don’t think anything would really need to change. It is adaptable, and on the one hand there is this architectural rigour, but it’s also a comfortable, functioning house that absorbs people and dogs and mess incredibly well. It’s not a concrete manifesto. It’s a home.”

Hugo: “The only thing that might be different now is Grace’s involvement in 1200 Works. We set up the architecture firm together to build this house and now the practice is growing, I have a new business partner.

“So we might buy Grace out, but this house really kickstarted the firm. There aren’t many emerging architecture practices that have a fully-finished new build house so early on. There’s a paradox that you can’t really build something until you have a client, and you can’t get a client until you’ve built something, but we already have a few projects off the back of this.

“A few years before finding this place, when I did my part three, I wrote in my closing statement that I wanted to go on to act as an architect-developer, finding infill sites to develop. This project really became a big part of fulfilling that aspiration. The golden rule with any development is that it has to be worth more than what you put into it, and I’m thrilled that’s what we’ve managed to achieve.”