Simon Conder Associates’ Eastcliff houses
Two houses on the windswept Cornish coast rely on traditional passive solutions
Architect Simon Conder Associates
Location Eastcliff, Porthtowan, Cornwall
Completion date April 2011
Nestled into a steep cliff with dramatic views of the Atlantic Ocean, two new houses designed by Simon Conder Associates are gradually taking shape.
The homes’ design has been influenced by their location on the more windswept north side of Cornwall, west of Truro in the village of Porthtowan, where their south-facing 1:7 steep hillside site is exposed to forceful gusts.
The client wanted sustainable houses that relied on traditional passive solutions, without the need for slick and costly high maintenance technologies. As a result the design is both simple in appearance and simple in its energy efficiency measures.
The planning application to replace two bungalows previously on the site with two modern houses achieving level 3 of the Code for Sustainable Homes sailed through without a hitch. The simple and holistic nature of the design impressed Cornwall Council, which is considering the scheme as an exemplar project, says Simon Conder.
The two houses have retained the names of their predecessors: Malindi, the larger of the two, will be the main family home, with two bedrooms and a sheltered inner courtyard on the upper floor and a large living/dining space on the lower ground floor; while Providence is 7m apart from its big brother and half its width. It provides a two-bedroom apartment on the lower ground floor and a studio space on the upper ground. The houses’ in-situ concrete foundations are now complete and the buildings are awaiting their concrete and blockwork superstructure and timber cladding.
How the South-facing colonnade restricts solar gain
Full-width iroko timber colonnades created on the south-facing elevations leave a striking feature on the new houses’ design and have several benefits.
Not only do the 1.2m-deep colonnades with floor to ceiling glazing make the most of the stunning ocean views, but in the summer months when the angle of the sun is very high, the timber canopy and brise soleil restrict solar gain. During the winter when the sun is at a lower level, solar gain is possible and can warm the rooms that have no heating.
Simon Conder has specified Schüco’s heavy, thermally broken, double-glazed folding doors, which slide open on castors. He says that in other house projects he has not been able to specify Schüco’s windows or external doors because of budget constraints. But because of the harsh weather conditions experienced in this part of Cornwall the client agreed it was worth spending £72,000 on the Schüco package (which includes the doors and all windows to both houses) with its invaluable warranties, U-value of 1.2W/m2K and silver anodised aluminium frame.
The system is intended to open up the houses to the sea elevations by folding back the full width of the glazed doors – Malindi’s colonnade is 11.2m wide; Providence’s 5.4m. The colonnades’ timber canopy gives some shelter from the sun and rain, while a 1.1m-tall toughened glass barrier prevents people or chairs from falling off the outer deck.
Iroko, an FSC-certified African hardwood, was specified to clad the houses’ colonnades, walls and roofs because of its workability and durability. Conder has used the same timber for six holiday homes being built in nearby St Agnes, and says he likes the way the untreated timber ages, gradually turning a silvery grey colour. He says iroko is ideal for the unforgiving marine environment because it is also very stable and achieves a crisp result.
Full-height 124mm-wide and 19mm-thick iroko vertical overlapping boards will be fixed vertically to horizontal battens which are in turn fixed to vertical battens and Eurofix thermally broken fixing brackets.
The external wall construction will achieve a U-value of 0.21W/m2K.
Other Sustainable Aspects
There are several reasons why Malindi and Providence have been built into the cliff. With their flat roofs, the new houses avoid obstructing the views of properties behind, and by excavating into the hillside and inserting two separate in-situ concrete retaining walls, two-storeys can be created, a key requirement of the client’s brief.
The design benefits from the natural insulating properties of the earth into which the buildings are sunk. Neither house has a boiler, the primary heat source being the slow release of the solar gain stored in the mass of the buildings.
During the coldest months, a wood-burning stove in Malindi can provide underfloor heating to the lower-ground living spaces. In Providence, underfloor heating is provided in the lower-ground living spaces and upper-ground studio via solar collectors on the roof, and radiators feed off the same source. Solar collectors also provide hot water to both buildings while cooking is electric. The only heating in the bedrooms is passive solar gain.
Original print headline - Project Eastcliff houses