In a deeply collaborative venture, client and architect McLean Quinlan worked together to create an elegant Passivhaus home in a country village
This understated and beautifully finished new house, a Roman villa with added technology, hunkers down next to an extensive existing walled garden in an East Devon village. Moreover it is a certified Passivhaus design which is ‘energy plus’, generating up to 40% more power than it consumes over a year. Unlike some other ‘Paragraph 79’ (previously Par 55) houses – that’s the clause in planning law demanding exceptional design for one-off houses in normally off-limits open countryside – it is not at all showy.
Indeed, says client and resident Nigel Dutt, in discussions with the planners, he at one point encountered the objection that it was not exceptional or innovative enough for the clause, which was an odd interpretation for a house as advanced as this. Moreover, it is not really in open countryside, with other village houses to either side of it. Nonetheless it was clear from the outset that this would be a tough one to get through planning and so the Par 55/79 route was the one to take. Despite the enthusiastic support of the local design review panel, the planning officers remained set against it. But the planning committee was in favour, and so eventually it came to pass.
Architect is McLean Quinlan, very much a family practice. Fiona McLean runs the London office, her daughter Kate Quinlan and son-in-law Alastair Bowden the Winchester one – strategically placed for the south of England one-off homes market. All were involved with this project along with others in the practice. The clients approached them directly, which is characteristic of their attitude: for instance the Dutts saw no point in hiring a planning consultant, preferring to do the necessary legwork themselves, and have designed and are implementing the landscape.
The Dutts – Nigel and Eileen – are mathematicians and retired software specialists (Nigel’s first place of work in 1970, he notes as an aside, was the young Norman Foster’s air-supported temporary HQ for Computer Technology in Hemel Hempstead). They lived in the village before the gently sloping gap site for this house came on the market. And, they point out, this is their home for life. It’s not a holiday home as such places can tend to be.
Living so close, the pair were closely involved in the design and construction, with Eileen taking on the landscape and both – given their backgrounds – fully up for the tech aspects of the design. There’s quite an impressive array of tech, which includes a 10kW rooftop PV array and battery storage, air source heat pump for underfloor heating, a phase-change heat storage battery for hot water purposes, a mechanical ventilation and heat recovery system, water from a borehole, and off-grid sewage system.
In the summer months the house generates more power than the local electricity supply company can handle (even with battery storage), and they have imposed a feed-in limit of 6kWh. The clients have had more than a year of occupation to monitor, and report: ‘In year one, the solar panels produced 10.450kWh of power. Total consumption was 7,480kWh, so the house is comfortably energy positive, with production exceeding consumption by 40%. Of the solar production, 4,920kWh was self consumed and 4.450kWh was exported to the grid. The remaining solar generated power was effectively lost because of the feed-in limitation. Of this 4,920kWh self-consumption, 2,250kWh was used via the battery. In total, just 2,550kWh was imported from the grid. The first year was also calculated to be carbon negative at around minus 500kg of CO2’.
In consequence the Dutts are going to invest in an electric car to soak up some of their surplus summer power. In the winter months they draw on the grid for the small energy needs of this massively insulated house, but can still use off-peak power to charge their storage battery.
Structurally the house has a smaller basement level cast in concrete lined inside with Tribus 4Wall panels – this contains a ‘living and media room’ flanked by the plant room on one side and storage space on the other. Above that it is a hybrid structure deploying SIPs, or insulated structural panels (again the Tribus 4Wall system, made locally), composite timber/steel beams, and some steel framing.
The long brick entrance elevation steps down the slope, jointed in lime mortar to reflect the old garden wall alongside. It extends beyond the house footprint on both sides as perforated screen walls. Behind this, the house is expressed as a simple rectangular structure clad in black Sto render. All glazing is triple-glazed Josko units.
The house is arranged as a sequence of rooms and spaces around an entrance hall/ courtyard, gained by a narrow lobby. The plan is therefore pretty close to that of the classic Roman house, the Vitruvian ‘Domus Italica’. No need for the Vitruvian ‘hortus conclusus’ or enclosed garden at the back, because here the hortus conclusus is the land between the house and the wooded site boundary. Besides, another is close by in the form of the pre-existing walled garden. The Dutts have bought a broad rectangular strip of this for their own use.
In a Roman villa the atrium would be open to the sky but in this Passivhaus the sky is seen through a triple-glazed rooflight, shaded by an external horizontal blind. The idea of a sliding roof was considered but rejected on cost grounds.
Perhaps one can see the memory of Ancient Rome also in that brick entrance elevation which gives little away beyond the oriel window to the dining room behind. The front door is clearly indicated but downplayed. A narrow vertical slit lights a bedroom. The windows get larger on the bedroom side of the house, facing the walled garden, and expand into a large framed view in the library at the back. Finally, on the south-west elevation to the main living/dining spaces, the walls dissolve into glass to take in the longer views to the hills beyond. In turn the glass walls can open up to a broad timber external deck.
The Dutts are clear that while some expensive items were ruled out, the quality of build and of finish was sacrosanct. Hence the use of warm recycled floor tiles and oak. Besides, the house is also something of a gallery for their collection of ceramics.
Lockdown meant that Eileen Dutt could get on apace with her landscape plan, which also has a practical consideration – a stand of silver birch trees will in time provide summer shade to that south-west elevation. Even so, after this summer’s hot spells the couple and their architect plan to fit some brises-soleils to the house to reduce peak temperatures.
With that tweak and with the landscape maturing, the house will bed into the land next to its neighbouring brick wall. An environmentally beneficial house of calm interlinking spaces, in and of its gardens.
Contract cost confidential
Net carbon emissions -2.44 kg CO2/m²/yr
Heating load 10W/m²
Energy demand 26 kwh/m²a
Energy generation 30 kwh/m²a
Architect McLean Quinlan
Structural engineer Tribus; Airey and Coles
QS Hosken Parks
Landscape design Client
Contractor Goulden and Sons
Building control Devon BCP
Passivhaus certifier Cocreate
Structural system Tribus 4Wall
Windows and external doors Josko
Bricks Wienerburger, Pastorale multi
Render Sto, Stotherm Stolit K
Internal wall finishes Clayworks Plaster, Farrow and Ball
Floor tiles MOSA Quatz
Wood floors Skema Oak
Terracotta tile Lubelska Luby