Greg Lomas of Foster Lomas reviews Kirkland Fraser Moor’s Ashraya house, a low-carbon property tucked beneath an arching roof and covered in a blanket of greenery that melds it with its Chilterns Hills setting.

Buildings.

We sit in David Kirkland’s studio, a stone’s throw from the Ashraya house, and discuss the back story of the house over a cup of tea. This is not the first Paragraph 80 house David has designed, but it is certainly the most local. In fact, quite a lot of his work is local so engaging and establishing relationships with the community is doubly important. It’s been a long road to completion. When the project started the policy at the time was Paragraph 55 and now it’s Paragraph 80.

The clients are friends and neighbours who wanted to improve their original property, a 90s developer house in a walled garden that previously served a nearby Grade 2 listed country house. Kirkland felt this was a compromise and suggested it would make more sense to invest in a new property on the adjacent site just outside the walled garden, which is not listed but does appear on the local borough’s registry of historic importance.

Initially he did some modest sketch schemes, which he thought would be acceptable for para 55 but the clients encouraged him to develop the bolder scheme that we see today.

It was contentious for the planners. They rejected it twice, but the majority of the village were quite supportive. After the second rejection, the local ward councillor called it into committee, giving Kirkland the opportunity to support the application in person, leading to the committee overriding the planning officer’s recommendation. The landscape contribution is key to being successful with this type of project, and, as Kirkland explained, ‘you must uplift the whole site and show an improvement. What you don’t want to do is to take away anything of value.’

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As we amble up the track from Kirkland’s studio towards the house, I catch a glimpse of Ashraya. It’s an intriguing sight appearing rather enigmatically, an abstract composition of curves and a boldly minimal chimney with most of the building’s form hidden by the arched green roof. The boundary between architecture and landscape is blurred, bringing to mind Scarpa’s Brion Cemetery and it’s subtle interweaving of the two.

I’m visiting on Open House day and it’s just starting to get busy with a few students and many locals, intrigued to find out exactly what this project is all about. There’s a palpable sense of interest and delight and you get the impression that this building will become a much-loved part of the village.

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Rounding the corner and facing the building head on, I’m struck by the enclosed nature of the site, trees to the south and the old garden wall to the north. Running towards the house is a slip wall, part of a secondary circuit of walls surrounding the walled garden. The slip wall is a critical element within the scheme and the seed from which the concept of the house germinated. It’s a modest wall, unremarkable in many ways, but of historic importance, so much so it took some convincing to persuade the heritage officer that part of the wall could be demolished and then extended into the sweeping curves that describe the house. The idea as Kirkland puts it ‘was to make a calligraphic mark in the landscape, like a piece of seventies land art’.

Approaching the house through the recently landscaped garden we enter an open courtyard that addresses the landscape we’ve just walked through. Curved flint walls describe the courtyard linking the landscaping with the arch of the house, representing a subterranean slice through the earth. We spend some time comparing experiences discussing the struggle for consistency with laying the stone walls and the time and care that must be lavished on it. Several different craftsmen have undertaken the work due to the pressure of the programme, but you need to look carefully to spot the different hands involved.

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Standing in the open courtyard at the front of the building we are seeing only a portion of a circle that pushes into the hillside and creates the flat site for the house. The concept was to create an indent in the gently sloping land, using the courtyard to define the curtilage of domestication. The remainder of the circle at the rear of the house creates a much more private space that relates to the living spaces.

Courtyards are an ongoing fascination and many of Kirkland Fraser Moor’s projects are based on this typology, often to ensure that the occupants can enjoy their property and the outdoor space with a degree of privacy and not have the clutter of life on show, a narrative that appeals to the planners. However, Paragraph 80 is also about ensuring that the building can be seen from the public point of view so a well-designed roof that can contribute to its landscape context is important. Being bounded by high hedges the house can only really be seen from the road, which satisfies policy but leaves other sensitive views unaffected.

Whilst it’s a very organic form, in plan the house is a rectangular box that sits within the circular courtyard with the meadow roof providing an indigenous blanket that blends the building into the landscape. Sub-spaces around the edges of the courtyard form areas where you can sit out and enjoy the landscape, a key part of the client brief. This also drove their desire for the house to be completely open to the outside. Inevitably this requires a lot of glass and achieving this in a sustainable building is challenging.

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For Kirkland Fraser Moor, sustainability is a core interest and I’m told they are always trying to find opportunities to test and experiment with ideas. Paragraph 80 provides the perfect opportunity, and that I think is where innovation is discovered.

As Kirkland explains it, the aim of the design process was to get as low carbon as possible, not just in construction, but in operation. The problem was that, while heating with renewables is entirely possible, you must think about cooling if you have a glass façade. They knew through previous experience that it’s possible to use renewable cooling utilising the under-floor heating system but this has limitations because it cannot go beyond the dewpoint, otherwise condensation forms inside the screed. Typically, the limiting temperature might be 16 degrees, depending on the humidity. They developed a system as a research project to explore how the cooling could be more effective and, working with Jonathan Gower from Aura, came up with a new approach.

This enables cooling by a further 8 to 10 degrees below the dew point by installing a secondary coolant system that bypasses the heat exchanger completely, so effectively requires no energy other than the pumps. This is then connected to a series of trench radiators and accepts that condensation will occur but is drained away. According to Kirkland, you can get the house to be like a fridge, far colder than it needs to be, but future proofed for increasing global temperatures. The house can also be naturally ventilated by opening up both sides of the glazed façades.

The glazing also utilises a very low G value and with the east-west orientation the deep vertical fins of the glazing operate as vertical solar shading, so as the sun moves round you’re getting deep shadow that mitigates the solar gain.

The whole house is readied for external blinds so the heat can be kept out further. Currently only the bedroom blinds are installed but, if required due to rising temperatures over the next 20-30 years, more can be installed.

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Much of the building, from the basement to the first floor, is constructed using off-site precast concrete. Above that, CLT timber provides the lightweight timber roof and structure. Two parallel arches running roughly north to south support 8-metre solid CLT planks to create the curved roof. The load is quite substantial as it is fully planted with 300mm of soil that, when sodden, can be heavy. You can walk over it but there are balustrades at the base of the arch, visually lost in the meadows on either side.

One target that drives creativity for the practice is the pursuit of the triple bottom line, ecological, economic and social. Projects like Ashraya are seen as opportunity to collaborate locally bringing in a local craft or business or develop a new product in a low carbon way and one can see how this provides a strong narrative to support the planning case.

Adopting the triple bottom line also catalysed the founding of D-Lab Studios, a community interest company whose mission is to prepare the next generation of creative professionals for the future economy through the provision of mentoring and Open Access maker facilities in Hertfordshire and London. It’s a tangible demonstration of the practice walking the walk.

Above us the curved roof sweeps across the space as we enter via a fully glazed double height hallway. The vertical emphasis is compressed as we walk through into the kitchen and beyond. The courtyard is visible, the circular dining space breaking the façade line and pushing into it creating the illusion that you’re sitting outside. The rear courtyard, in contrast to the front, is much more enclosed and surprisingly austere due to the higher walls retaining the hillside – it feels a little like a Japanese karesansui dry garden.

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