'Nothing is softer or more flexible than water, yet nothing can resist it.'
Lao Tzu

Sintryndel - a solar hemicycle residence near Honiton, Devon.

SUMMARY: Shown here are sketch plans perspectives and site images for 'Sintryndel' - a proposed newbuild four-bedroomed contemporary family ecohome on a sloping rural site near Honiton, Devon. 'Syntryndel' means 'round, circular, endless' in Anglo Saxon, depending upon the context within which it is used.

DETAIL: The site is a three acre tract on a hillside location within the Blackdown Hills Area of Outstanding Natural Beauty (AONB). The site lies to the north of the market town of Honiton. It is sufficiently isolated to have no visible neighbours. The site has far-reaching views towards Dumpdon Hill (an iron-age hill fort) and Stockland Hill to the Southeast of the site (see site images).

Planning Permission was granted for a residence on the site in 2008 but the building work never proceeded further than the construction of foundations and ground floor slab. The current design is for a replacement dwelling of broadly similar area and volume, but of radically different design - it is proposed to be a 'solar hemicycle'.

A 'solar hemicycle' is a part-circular design ('hemicycle' - part of a circle) which utilises passive solar gain as its main heating input strategy (hence 'solar'). This type of residence was 'invented' by the American architect Frank Lloyd Wright with the design of the Jacobs residence in Middleton, Wisconsin in the USA, in 1942. Under our current circumstances of the need for sustainability-sourced non-fossil fuel derived energy in our buildings solar-passive designs have achieved a relevance they did not have when they were originally designed. They are able to 'harvest' heat from the sun in order to heat buildings without use of fossil fuels.

The current design has been developed far enough to have received a Predicted Energy Performance Certificate (PEPC), for which it scores 'A' classifications in both Energy Efficiency and Environmental Impact.

The plan, which would normally be orientated broadly south, has been rotated east through 30 degrees to avail the house of the views downhill towards Dumpdon and Stockland Hills. This rotation reduces the effectiveness of the glazed south facing solar collection wall by about 10 percent, but this can be compensated for in the design of solar shading.

The premise of this design as with other solar passive designs is to 'harvest' the heat of the sun by capturing it and storing it. The design achieves this by streching out a large double glazed window/wall facing broadly south through which sunlight passes to fall on surfaces of high thermal mass (such as stone and concrete). The high mass elements 'convert' the shortwave solar energy to longer wave heat energy, and slowly emit heat. The heat stored in the thermal masses gradually dissipates throughout the house over time thus heating the house without cost or use of fossil fuels. This is to be allied to high levels of insulation and a great deal of attention paid to the sealing of potential air leakage points. This design, however, is not a 'Passivhaus' as no constant mechanical ventilation is envisaged. The aim of this design is to achieve a comfortable internal environment naturally, without the use of a primary mechanical heating system, using the simplest strategy which is basically: passive solar gain, very high insulation, very high thermal mass, low ventilation leakage, and passive cooling.

Cooling is as important in a solar passive design as heating, and natural cooling is to be provided by solar shading, high thermal mass, cross ventilation, and natural water cooling.

The materials to be used are local 'chert' fieldstone for the main masonry walls, lapped or 'board and batten' Douglas Fir boarding, Douglas Fir framing to all doors and windows, and glass. Where plaster is to be used this is to be made up using local 'greensand'.

The statistics for the proposed design are:

Number of storeys: 2.

Number of bedrooms: 4.

Gross internal floor areas: Ground Floor: 160 sq. m.

First Floor: 108 sq. m.

Plant areas in carport structure: 22 sq. m.

Total gross internal floor area of main house habitable areas (both floors): 268 sq. m.

Footprint of all enclosed building structures: 235 sq. m.

Total area available for solar arrays on the main roof: approx. 20 sq. m.

Ground level perspective view from South. The masonry walls are to be local 'chert' fieldstone, and timber elements such as the balconies are to be lapped Douglas Fir.

Preliminary sketchplans and ground level perspective view.
View looking East showing the existing foundations and slab, to be broken and recycled as hardcore. The land slopes down to the East, revealing extensive views in that direction.
Aerial perspective view from South.  This view clearly shows the 'leaf' shape, with the curved assembly of solar arrays on the roof.
This view Eastwards shows the drammatic view of Dumpdon Hill, site of an ancient hill fort. The new house has been rotated to avail itself of this view.
Siteplan showing how the house has been rotated to the East to catch the views downhill in that direction.

Ground level perspective view from East. This view looks uphill towards the house. The curved elevations produce narrow prow-like end aspects such as this.

Ground Floor Plan. The wall to the rear of the Lounge (containing the fireplace) is to be of 'chert' stone construction to add thermal mass. The floor is to be polished concrete for a similar reason.
First Floor Plan. The cutback in the internal balcony at the front wall is in order to facilitate a double layer of insulating curtains to be drawn across the solar wall at night in order to keep the 'harvested' heat in.
Results of a Predicted Energy Performance Certificate (PEPC) assessment for this house gives 'A' classifications in both Energy Efficiency and Environmental Impact.