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Architect Ben Ridley used all of his expertise to upgrade an ageing London dwelling to create a low energy home for his family, whose minimalist interiors bring a focus on the natural materials used

TEXT TOM BODDY IMAGES LORENZO ZANDRI & CHRISTIAN BRAILEY

In the leafy London suburb of Muswell Hill, an outmoded Edwardian terraced house has been brought back to life and transformed into a low energy family home. With an experienced architect at the helm of the build, energy usage has been dramatically reduced, including via Passivhaus-level design in some areas. While the original facade has been retained, the interior offers a clutter-free, contemporary design, filled with natural textures and simple layouts.

While many self-builders may be novices, Ben Ridley, architect and founder of Architecture for London, has a variety of experience under his belt in the design and build of homes. He has always been passionate about sustainable design. During his studies at University College London, he picked up the Sir Andrew Taylor Environmental Design award, fuelling this enthusiasm further.

Since establishing his own practice in 2009, Ben has been a part of several award winning projects and ensures that low energy design is prioritised in all of their projects.

But although he has extensive experience in conceptualising and delivering ideas for clients, designing a space for himself and his family was something he’d not previously experienced. Their idea was to find an “unloved home” and turn it into a contemporary space that worked well for him, his wife and their daughter.

At the same time, Ben’s ambition was to create an “exemplary demonstration” of how a traditional terraced building can be successfully adapted to reduce energy use. “I wanted it to be designed so that it could be built within a reasonably tight budget, this was key to show that low energy retrofit could be scaled to the city, and even nationwide,” asserts Ben.

The house he found in Muswell Hill, originally built in 1907 and not refurbished since the 1970s, was the “perfect fit,” says Ben. There are woodlands and parks nearby, and it’s an easy commute by bike to his office in Farringdon.

The house was in poor condition however, and in need of a full refurbishment. As well as suffering from considerable dampness and condensation issues, there were large amounts of mould. According to Ben, this was the result of non-breathable cement-based renders and plasters which had trapped moisture.

The interior was dark; as the garden was north facing, the rooms at the back of the house severely lacked natural light. “The house was also very cold, with no insulation and single glazed windows.”

Despite these issues, its layout and shape was just right for Ben and family. The project also represented the “perfect opportunity” to showcase how a typical London terrace could be updated into a sustainable refurbishment, on a budget.

BRIEF & PLANNING

Ben saw it as crucial to consider both embodied energy and energy in use from the outset. In terms of the interior, the brief was to create a family-orientated, relaxing space featuring natural colours and rich material textures. “I wanted it to feel like coming home to a calming sanctuary,” he says.

As the rear extension and loft conversion could be completed under permitted development rights, the process of achieving planning was “fairly straightforward.” The construction phase was where things got a little bumpy.

With work commencing during the various lockdowns, most of the neighbours were working from home while the “noisy” building works took place which “inevitably led to tensions.” Ben explains how “some neighbours even took to filming the workers and posting footage on Twitter and tagging the police, in a misguided attempt to find wrongdoing.” Dealing with neighbours’ complaints was a widespread problem for self-builders during the pandemic, despite “construction work being allowed to continue during the lockdown,” Ben remarks.

Also, due to “lockdown supply issues,” several of the products he specified, such as the roof slates, couldn’t be sourced. “We originally wanted to use diamond-shaped roof slates for the loft conversion, however only the regular rectangular slates were available.” On top of this, the family were living in a one-bedroom flat during this phase, “which was challenging at times!” says Ben.

LIGHT & HEAT

The project added a four metre extension to the rear of the house, creating space for a bright dining room with a large triple-glazed circular rooflight.

To combat the lack of natural light on the ground floor, some of the partition walls were completely removed, enabling light to flow through the rooms and resulting in “a brighter, open plan space.”

Full height glazing at the back provides a connection to the outside while offering views out to the somewhat jungle-like garden. The extension is contemporary in its design, but its exterior harmonises with the existing structure; the grey render is the same as that used over much of the rest of the home’s exterior. Built using a ‘super insulated’ SIPs panel system including 172 mm of high performance insulation, the extension makes a large contribution to the project’s sustainability credentials.

Upstairs, a full-width rear dormer, replacing the original roof timbers, creates space for a TV room and the combined shower and utility room. Ben explains that a further new timber structure created an “additional dormer over the rear outrigger roof” to provide a small loft bedroom.

These alterations have created highly functional spaces, while making carbon savings from avoiding steel in favour of timber. The home’s layout now includes a large open plan kitchen/living/dining space filled with natural light on the ground floor, plus five bedrooms and two bathrooms on first and second floors.

Interior

The interior boasts a strikingly minimalist design. With uncomplicated, streamlined forms and simple finishes such as greys and whites, the home achieves a ‘less is more’ aesthetic. “I enjoy clean and minimal spaces because they help calm the mind after a busy day,” says Ben. He adds that an important goal of the minimalist approach was to “focus on the beauty of the textures in the natural materials.”

The key material palette is limited to oak, lime plaster and natural limestone, creating a calming environment within the living spaces. Ben explains how these materials were carefully selected to minimise the number of deliveries to site, helping to reduce the project’s embodied carbon.

Parts of the home have been stripped back to reveal the original structures. The ceilings throughout the ground floor have been removed to reveal the timber joists. Moving through the interiors, further timber elements are introduced which add warmth to the minimalist design. In the master bedroom Ben used Douglas fir floorboards and joinery details. The kitchen and all the wardrobes are based on IKEA carcasses, with bespoke fronts in oak-faced plywood.

The interior lighting, supplied by Orluna, has been designed to “provide pools of light” with a warm colour and “very good colour rendering,” explains Ben. Complementing the minimal feel, the light fittings are kept simple – on the ground floor they are part concealed within the exposed joists. LED strip lights form accent lighting in the kitchen, bathrooms and master bedroom. Viabizzuno pendants in the living areas and master bedroom provide “candle-like” spots of light which highlight the spaces’ natural textures and materials.

Eco measures

The home is filled with high-insulating materials and triple glazing; this alone has improved airtightness as well as “dramatically” reducing the property’s energy demand, says Ben. As a further means to reduce embodied energy, a timber structure was used “wherever it was possible,” including the suspended floor in the extension as well as the loft conversion. To avoid “energy intensive” steel box frames, masonry nib walls were retained on the ground floor.

A single combi boiler powers the underfloor heating (UFH) which runs throughout the home. “In practice, however,” says Ben, “only the ground floor UFH is required; this is generally enough to heat the entire home.” While he admits an air source heat pump would have been a preferred option, the £15k investment that it would have required was unfortunately slightly out of his budget.

The project has been externally as well as internally insulated, which was achieved under permitted development. The external insulation was installed to 170 mm overall – one layer at 140 mm and the other at 30 mm. Ben explains the reasoning: “This meant we could stagger the boards to remove gaps and therefore reduce the possibility of cold bridges.” He adds: “This required extra time to install, but it wasn’t difficult.” The thick insulation has achieved Passivhaus-level U-values of around 0.15. The front of the home was insulated internally, so the Edwardian facade could be retained.

With it being a highly insulated, air-tight build, Ben installed a Mechanical Ventilation with Heat Recovery (MVHR) system. As these systems can take up a large amount of space, the supply and extract pipe runs had of course to be considered at an early stage of the design process. To accommodate the ducting, ceilings have been dropped in the hallways at upper floors. In addition, a riser was concealed behind a new partition wall next to the staircase, containing ducts running between floors.

Completion

The finished result offers a simple, clean and contemporary set of spaces, providing Ben and his family with a calm and minimal home that works for them. The combination of its eco features results in the home only producing annual CO₂ emissions of 4600 kgCO₂e, and achieves what Ben set out to do, of turning a standard London home into a sustainable building.

In terms of functionality as a family, Ben says he is “really happy” with the open plan spaces on the ground floor. He adds, “it works well for family life and also when friends come over. Often in London homes, living spaces and kitchens are split over different floors or different parts of the house, so it’s great to have all the living areas together in one space.”

He is delighted with the natural materials:
“The natural limestone is a pleasure to see every day. The way that sunlight catches it and reveals the ancient fossils is fantastic!” One interior design feature that he’s particularly happy with is the continuous curtain in the main bedroom that “works really well to create a cosy space.” Overally, the house is “warm and comfortable throughout the year, and is a real joy,” he enthuses.

Ben has one final learning to share from designing this highly energy-efficient house. Namely, the importance of “airtight tapes and membranes being installed carefully. Architects need to ensure it’s carried out properly, and that the site workers understand the products and principles of airtightness.”

HIGH POINT

“Moving into the home!”

LOW POINT

“Realising how much work still needed to be completed after moving in day!”

CONTACTS/SUPPLIERS

NATURAL STONE

Design Driven / Grassi Pietre

www.designdriven.co.uk

www.grassipietre.it/en

DOUGLAS FIR FLOORBOARDS

Dinesen

www.dinesen.com/en