Julian Marsh’s house is a lesson in how to build and live ecologically, says Peter Blundell Jones. Photography by Anthony Coleman
In the era of the image, when all is advertising and greed is a common goal, the sight of dream houses for the pampered rich has begun to pall a little, particularly when we know that the images have been Photoshopped for maximum desirability.
Money still, it seems, means lots of space and all the latest gadgets, and the international style’s way of vanquishing the climate by applying limitless energy remains the quick route for those who can pay. But what if, instead of building your house for prestige and image, you build for minimal planetary impact?
Julian Marsh of Marsh:Grochowski architects and his artist wife Judy owned a beautiful house with a sizeable garden in a Victorian suburb of Nottingham, but increasing concern for ecological values led them to sell up and rethink their way of life. Marsh wanted the chance to experiment with energy-saving measures in daily use, to set limits on embodied energy and to reduce dependency on local services. He was also curious to experiment with materials and to undertake parts of the work himself, a craft experience hardly possible with commercial work.
To reduce car journeys and make most things reachable on foot, it was necessary to move into the city, and a site became available in The Meadows, an industrial suburb next to the river Trent that had been isolated by the post-war ring road, resulting in the usual degradation, although local co-operation is now on the rise and a recovery is taking place. A plot at a southern street corner between terraced houses was occupied by a small industrial complex known as ‘The Meat Factory’. Its run-down fabric, a hotchpotch of brick walls and timber-trussed corrugated asbestos roofs, was undistinguished and the ground polluted, but the site faced the river across the riverside park. It could offer two storeys backing up against the gable ends of existing terraces, and it was desirable to raise the ground half a metre against a hundred-year flood risk.
The Marshes decided to rebuild. They wanted a small garden to grow fruit and vegetables, which needed southern exposure and sheltering walls – such containment against cold winds is the equivalent of being about 320 kilometres further south. With its courtyard-garden at the corner, the house took an L-shaped form, embracing the garden and increasing the area exposed to the south and west. In an act of neighbourly generosity it also covered the terrace end walls, reducing their heat loss.
The accommodation divided easily between two wings: a wide one to the north for the double-height gallery and living space with adjacent studio and bedroom above; and a narrower one to the east with studio downstairs and kitchen and living rooms above, enjoying the park view. Linking the two wings is a conservatory-like space which opens onto the garden. Partly glazed and partly clad in high U-value recyclable polycarbonate, this contains the passages and stairs, but it was left unheated and was insulated from the occupied rooms in order to work as solar collector and climatic buffer. The temperature exchange possibilities of this volume by opening and closing panels to inner rooms and to the outside air was a key element of the energy strategy.
It was oriented directly south for maximum solar gain, and therefore its plan geometry is skewed five degrees in relation to the planning grid of the site. A further skewed angle was introduced to allow a line-of-sight link from gallery to front studio, also producing a containing corner for the wood-burning stove. The buffer has stack venting at roof level to dispose of summer heat, with a sun-catching chamber on the front to produce convection and motorised vents for adjustment to changing conditions.
The 600mm floor void prompted by flood avoidance also serves as a cooling plenum. The upper passage has a floor of recycled glass to preserve light transmission to the rooms behind, and the solid concrete stair wall provides thermal mass for heat storage, aided by racks of plastic bottles filled with wax-like substances that give and take their latent heat of fusion. A second buffer space is found at the upper south end of the east wing, where not just sunshine but the best long views of the park are available without interruption by the street.
The wing ends in a balcony-like bay with glazing that folds entirely, and there is an inner wall of glazed doors to protect the living space in cold conditions and at night. Within the balcony’s east side a glass-topped box offers a convenient seat to enjoy the sun and view, but also acts as a daylight source for the studio below. In the house there are many such examples of borrowed light via windows or rooflights, eliminating dark corners, increasing awareness of external conditions and minimising the need for electric lighting.
The Meat Factory had occupied a clear rectangle of site at ground level, but to have developed the plot fully to two storeys would have encroached on neighbours’ light, so a more open rear corner was negotiated with the planning authority including a small back yard. The building profile steps three times in plan to allow a northward window in the kitchen, a north-facing turret-like corner for the larder, and a corner to the gallery room projecting at ground-floor level but receding above. This device, incorporating both a rooflight and a clerestory aimed at the distant northward sky, turns the restriction into a virtue.
Apart from incorporating passive solar heating via the main buffer and the layers of south-facing windows, the heating strategy was to insulate well, relying on high thermal mass to smooth out the changes in external conditions, one reason for the exposed concrete floor slabs and the centrally placed masonry masses. Background heating to maintain a liveable temperature of 19°C is provided by a piped water system in the floors driven by a nine-kilowatt electric heat pump, which borrows its heat from an aquifer deep beneath the site tapped by two 70-metre boreholes.
To top the system up in autumn before the ground-source is turned on, and to provide respite during power cuts, a five-kilowatt wood-burning stove stands at the very heart of the house. A more directly visible energy source is the large array of south-facing solar cells set just above the main buffer. They produce around 3,000 kilowatt hours per year and, allowing exchanges with the grid, are expected to supply most of the electricity. This solar device acts simultaneously as a visor to the glass against high summer sun while letting low winter rays pass through. Marsh intended to add a wind turbine, but the local authority refused it on grounds of noise. Hot-water supply also involves a solar system, with five square metres of panels in the front wing’s roof expected to account for about 70 per cent. Usable temperatures are obtained out of season by topping it up with the heat pump.
Another planetary issue dear to Marsh’s heart is the over-consumption of water. Nottingham is fed by dams in the Peak District, created in the 1940s by displacing communities and drowning villages. Many such reservoirs are visible on flights over the Pennines, but dry summers seem increasingly to bring a crisis of supply. When, on the other hand, it gets too wet, the rapid run-off from buildings and tarmac produces flash floods. The rainwater that is collected is relatively clean, and adequate for washing purposes after UV treatment against bugs. The requirement to elevate the house against flood allowed the incorporation of a large underfloor cistern, so the mains need only be tapped for drinking and cooking.
The heat-exchange boreholes allowed the inclusion of an extract pipe for garden water in the tradition of local wells, and modest quantities can be taken legally without significant impact on the water table. Another aspect of water treatment is bodily waste. We still profligately flush the toilet with drinking water, yet we need not flush at all. We could instead compost the waste, and use it as fertiliser rather than filling the sewers, and there would be less need for them too. The Marshes’ composting toilet was for the building inspector the strangest departure from normality and they were obliged to add an ordinary water closet as a reserve, but in practice the composter works and does not smell as long as urine is separated.
The avoidance of dishwashers and ovens is understandable in a house trying to exist electrically on the modest output of solar cells, although the Marshes have a carefully chosen hob and a microwave, one of the few technical innovations which does involve less energy. More surprising is that they have denied themselves both fridge and freezer, depending instead on a north-facing larder ventilated from the back yard. This is not just an energy-saving measure for the house, but a larger commitment to obtaining fresh food and storing it only for limited periods. It might appear to be a return to early 20th-century conditions, but it is more than that.
Large-scale refrigeration has altogether changed our eating habits and our relationships with the places and times where things are grown, so the supply of strawberries at Christmas means they are no longer a treat in June. Suspended animation by freezing and endless truck journeys now dominate the food industry, gulping up oil and clogging roads. Preservability and visual attractiveness in food have become the priority for business and therefore the customer. But an encounter with fresh food in local markets or a place with a lively local cuisine soon reminds us of the difference.
Another aspect considered was the embodied energy within building materials and their added component of travel. Marsh used hemp insulation, clay plaster and timber certified as sustainable by the Forest Stewardship Council. The timber beams of the structural frame were made of pressed recycled timber and local sweet chestnut was used for the cladding. Other elements were chosen because they were made from recycled material, such as ‘Durisol’ blocks in the garden. Waste was reduced to a minimum and leftover materials were used in other situations, and wherever possible temporary works such as props and shuttering were included later elsewhere. Some demolition materials were re-employed, and materials were chosen with an eye to eventual recycling. Even the reorganisation of the whole building for a different configuration of uses was considered, to avoid a later need to demolish.
So what can we learn from it all? First, perhaps, that this example is highly contextual, closely adapted to the site and orientation, acknowledging neighbours, and even making advantageous use of underground conditions. Given another site, Marsh might have done something very different. Second, ecological architecture has mainly been seen as technical but needs to be thought of as cultural and in relation to the way of life contained. It is not just a matter of adding insulation or using another form of heating, but of changing our habits and looking at our consumption as a whole.
Every detail matters. We should value the site and the sun, acknowledge the seasons, enjoy daylight in all its variants, reduce food miles and grow some of our own produce, and negotiate with the climate by adjustment of buffer spaces instead of trying to suppress it. We should walk when we can and use an electric car when we must go further. Sooner or later we will all have to mend our ways, and the sooner we do so, the less painful it will be. It is not so much a matter of money as the way we choose to spend it. Global capitalism is blind, interested only in profits and wedded to growth, limited only by a sense of what it can get away with, increasingly immoral and hard to regulate. It could be otherwise, if only we were prepared to look at the whole, to stop fighting the planet, and to live more modestly, generously and intelligently.
Start on site March 2006
Contract duration 4 years
Gross internal floor area 190m2 (heated) 31m2 (unheated)
Form of contract Self-build
Total cost £500,000
Cost per m2 £2,262
Client Julian and Judy Marsh
Architect Marsh:Grochowski Architects
Structural engineer Price & Myers
M&E consultant Buro Happold
Project manager Julian Marsh
Approved building inspector Stuart Musson, Nottingham City Council
Annual CO2 emissions 1,403kg (estimated)
Structural frame Flitch Beams with Trus-joist Macmillan Parallam paired columns and beams Rusted steel ties
Lower walls Courtyard: External: Hanson Saxon Red Internal: Knabel Smooth White brickwork
Brick cavity walls: External: Hanson Saxon Red, Tarmac mortar Rockwool cavity batts: 120-150mm Internal: Knabel Smooth white or diamond white glazed, white mortar Internal: 100mm blockwork
Upper walls 1. VM zinc anthracite cladding, breather membrane 18mm ply 40mm vent space Gutex Ultratherm 50mm T&G insulation board Timber frame, hemp batt insulation Sisalkraft 714 vapour barrier Skimmed plasterboard
2. Inwood Sweet Chestnut rainscreen 40mm vent space Solitex Po Clima breather membrane Gutex Ultratherm 50mm T&G insulation board Timber frame, hemp batt insulation Sisalkraft 714 vapour barrier Skimmed plasterboard
Roof VM pre-weathered zinc longstrip Deltatrella vent membrane Trus-joist Macmillan TJI joists 300mm hemp batts Sisalkraft 714 vapour barrier
Copings Dales Fabrications: ppc aluminium
Windows and doors Ideal Combi Futura Solarlux Systems. Balcony Glazing SL25 Sunspace glazing SL65
Rooflights Glazing Vision
Sunspace wall Danpalon UK: Danpalon 16 soft
Garden shed Timber frame with Inwood sweet chestnut T&G cladding
Steel gates and shutters All steel fabrications: Corten
Hollow-core concrete floors Milbank
Precast concrete elements Castle Concrete recycled aggregate
Internal doors Bespoke Douglas fir insulated doors
Internal walls Rodeca Translucent 50mm panels
Wall finishes Where pictures hung: white-painted plaster Mass walls: clay plaster on Knabel facings, white mortar
Ceiling finishes Gallery: Osmo white-stained birch-faced ply Concrete ceilings: Guard Industries Protect Guard Color: white concrete stain
Staircase and bridge Canal Engineering pre-rusted and lacquered fabrication Recycled glass floor
Ground-floor finish Dalsouple Dal-naturel Dal-uni/dal-tex: Lait and Marron Negre
First-floor finish The Floor Gallery: white-stained engineered oak, Polyplumb underfloor heating system
Lighting Ocean LED: General lighting units Concord Lighting: display floods/spots Lite House Europe: photoluminescent strips
Bespoke control system S Roberts and C Harris-Marsh
Photovoltaic panels Sanyo HIT range with SWA Inverter
Solar HW Schuco flat plate collectors
Rainwater recycling Conder Environmental Solutions 4,000-litre tank, Wisy Leaf Filter, Wedeco Aquada UV filter
Heating Dimplex 9kW ground-source heat pump (two 75mm deep bores) Rias pilar stove
Deep bed planters Durisol 190 uninsulated block screw-fixed, foam-filled inter block cavity
Fencing Recycled palettes
External surfaces General surface: 20mm recycled crushed brick Deck: stained softwood Paving: Marshalls Saxon Tiling: Solus Ceramics Apavisa Copper