Carl Turner and Mary Martin, who appeared on Grand Designs back in 2012, took an uncompromising approach to build their dream eco home on a residential plot in south London.

brixton glass house - grand designs tv house - exterior  

Image: The house uses 350 glass panels, with 200 on the top floor. The milkyopal quality has been achieved by dipping them in a hot kiln of paint. Photo: Rachel Whiting

When it comes to building and renovating projects, Carl Turner and Mary Martin are a couple who just can’t say no. They bought their first house within months of meeting nearly 25 years ago, and have been on a continual leapfrog to bigger and better renovations since, sometimes two at a time.

But increasingly they longed for somewhere they could stop, tailored to fit their minimal leanings like a glove. Opportunity knocked with a derelict house in Brixton, south London. It had no kitchen, a WC in the dining room, and ‘carpet so rancid it could have walked,’ says Mary, but there was potential to sub-divide the plot with enough room in the long garden to build a separate house, which had direct access from the street behind.

A similar plot two doors up had already done this, parcelling off its garden to make way for an ambitious new-build, so they followed suit, renovating and extending the existing house and designing their dream home for the back. ‘I started off sketching a house the planners would like, with a pitched roof and dormer windows, because I thought we would never get permission for anything too contemporary,’ explained Carl, an architect. ‘But then we just said: 'Let’s forget the planning system, design the house we want and make a case for it.’

Watch the episode: Brixton, 2012

brixton glass house - grand designs tv houses

Image: ‘During the day, when the blinds are pulled down and the gates are shut, it is quite an introverted, private house,’ says Carl. ‘But as you open the blinds and slide the windows back, it’s really connected with 
the street. Photo: Rachel Whiting

First time lucky

And their boldness paid off: permission was granted first time, without even going to committee. Their design – a stack of three cantilevered glass-clad rectangles – might look alien among its Edwardian and Victorian neighbours, but Carl argued that it could become part of a terrace of unique houses on the street (there were three other plots like theirs, ripe for sub-division).

The only problem now was how to fund their daring design. Carl and Mary broke even when they sold the existing house minus half its garden, so the land cost them nothing, but it took months to secure a £280,000 mortgage for the build, which was topped up with £20,000 savings. And it quickly became clear that this was not enough: cantilevered glass houses don’t come cheap, especially when two storeys have no internal walls and there are heavy concrete floors throughout, requiring a steel frame and 14 concrete piles to anchor it to the ground. 

To raise another £250,000 they sold their Norfolk barn, which gave them enough to build without compromise. The final cost was £450,000, plus another £100,000 for joinery and internal fixtures and fittings – which is a steal, considering a Victorian terrace nearby costs around £750,000. Even better, the house would be cheaper to run than any Victorian terrace, thanks to its massive eco credentials. 

read a free issue of grand designs magazine

The green house

At the time, Carl believed it to be one of the most energy efficient in the country, with photovoltaic thermal (PVT) panels on the roof providing most, if not all, of their hot water and electricity, and a ground source heat pump below the house powering the underfloor heating. They also had a cutting-edge system that sends excess heat from the PVT panels down to the heat pump to improve its efficiency, and they have a tank to collect rainwater for the WCs, washing machine and outdoor taps. The house is  also super-insulated and wrapped in an airtight membraneto stop heat leaking out. Green? This house is fluorescent. But the big question is how locals would react to such a statement building.

Read more: Beginner's guide to ground source heat pumps 

brixton glass house - minimalist interior kitchen and dining room - grand designs tv houses

Image: Windows occupy the entire width at either end of the kitchen-dining-living space. Half of them are concealed behind the external glass panels so light still comes in, but Carl and Mary’s privacy is protected. Photo: Rachel Whiting

Local favourite

Indeed, they seem to love it, with passersby taking photos. ‘You can’t build a house like this and be shy,’ said Mary. ‘It’s not a fortress.’ Their involvement in the build also helped pave the way for a positive response from the community. The build took 15 months and Carl and Mary were there throughout, canvassing support for the design at the beginning and then chipping in on-site – Mary running errands and keeping the team happy with supplies, and Carl helping his brother Neil, who was the main builder, by doing the plumbing and landscaping, helping fit the windows and overseeing the arrival of the steel frame and concrete panels. 

‘When you’re getting your hands dirty, people see that you’re not just some rich people getting a luxury house built for them,’ said Carl. ‘We’re not property developers. They are pleased to see we’ve invested in building our home here.’

brixton glass house - minimalist interior living room and kitchen - grand designs tv houses\

Image: All the visual clutter, such as skirting boards, door frames and cornices have been removed to create a sense of calm and continuity. Carl’s ethos was to create a sense of flow between the walls, floors and ceiling surfaces. Photo: Rachel Whiting

Minimalist layout 

The open-plan ground floor is a flexible space for Carl’s architectural practice, which can double as an entertaining space with a long table and outdoor terrace, and could be turned into a self-contained studio  flat in the future. The first floor is functional and clever,  with a bedroom at either end separated by a bathroom in  the middle which has sliding walls so it can be opened up, making it feel twice as big. The second floor is the main kitchen-dining-living space, with treetop views to the front and back of the house. And the roof terrace is the crowning glory, surrounded by glass panels for privacy, but with a platform for stunning views across the city. The Shard,The Gherkin and St Paul’s are all clearly visible. 

Back in 2012, Carl and Mary said that this build, for them, was the one. ‘There might be a little beach hut,’ said Carl. ‘But this house is a watershed for us. We could never outdo it, so why would we even try?’ 

However, since airing, Carl and Mary have since sold the home, with Carl telling the Architecture Masters podcast: ‘We enjoyed the house for a few years… We kidded ourselves, myself and my wife, telling ourselves that it was our forever home.’

‘After a couple of years, I was itching to do more projects and I needed some more money to pursue [these].’ 

brixton glass house - exterior view of bedroom - grand designs tv house s

Image: The stepped design of the house has created space for a wildflower meadow outside the main bedroom, which encourages biodiversity, soaks up rainwater and provides some cherished green space in a house that takes up its entire plot. Photo: Rachel Whiting


Property Detached self build home 
Project started 2010
Project finished 2012
Cost Approx £550,000


For more Grand Designs homes and self build inspiration, read Grand Designs magazine digitally for free now by registering your details

read a free issue of grand designs magazine


5 of best self build projects using timber 2020

Kitchen extension ideas to improve your home

How to reduce the carbon footprint of your build

Kevins Column

Grand Designs Live Online: Self Build & Renovation Weekend 31 July – 1 August 2021

Discover free home project advice and product recommendations from the comfort of your own home. Register now to express your interest.
Grand Designs TV Houses

Inside the Grand Designs earthship house

Take a tour of this Grand Designs earthship home and discover the methods and materials used to build it
Grand Designs TV Houses

Modern barn house | Grand Designs

Take a tour of this modern barn, which featured on Grand Designs, to discover how it was built on a low budget
Grand Designs TV Houses

Grand Designs House: Tudor Guildhall Restoration in Suffolk

Revisit the restoration of a Tudor Guildhall and the conversion of an adjacent barn in Stowmarket, Suffolk, from Grand Designs series 7
Grand Designs TV Houses

7 Grand Designs TV houses designed to make the most of the views

The right plot of land could offer up beautiful vistas from your windows. Here are 7 such self builds from Grand Designs, designed with spectacular...
Grand Designs TV Houses

Grand Designs 2021: TV houses before and after

At the end of this series of Grand Designs, take a look back over each project from it's starting point to the finished home.