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Reduction of the ecological footprint

These scenarios illustrate the importance of addressing energy consumption in the South West's current housing stock, as new homes built to higher energy efficiency or even to ZED standards will not achieve a significant reduction in energy consumption or in the ecological footprint. The ecological footprint results for these scenarios are shown in Figure 1.

Figure 1
Housing and domestic energy base case and scenario ecological footprints for the South West

fig 1

Landrake eco-housing case study

Wishing to stimulate 'novel and sustainable solutions' to the shortage of affordable homes, the Cornwall Sustainable Building Trust ran a competition to design a development for a small site provided by Caradon District Council in Landrake near Saltash. Landrake is on the A38 between Liskeard and Plymouth (about 12km away from each).

The competition winner, architect Bill Dunster, proposed a 'carbon neutral construction strategy' producing a development with zero fossil fuel energy demand and built to the emerging Zero Energy Development (ZED) standards, which aim to reduce a broad range of environmental impacts relating to water use, transport, waste, food supply and material consumption.

Designed to be both affordable and environmentally benign, while providing a high quality of life for residents, the Landrake development is ideal to illustrate the potential for sustainable new build in the South West.

The site comprises two blocks of high density, low rise housing (containing five homes) surrounding a communal green space and allotments. The site is bordered on two sides by wildlife planting, and on another by existing housing. An access road runs along the remaining boundary. (For a full description of the development see bdaZEDfactory, 2004).

Design features

The design reduces energy demand to 16,800kWh/year through super insulation and massive construction*, maximising solar gain, and the incorporation of passive cooling. The residual energy demand is met by a mix of on-site renewable energy sources; a communal woodchip boiler, two wind turbines, solar water heating panels, and photovoltaics. Surplus electrical energy (estimated at 9,200kWh/yr) is used to charge electric pool cars, and will provide an estimated 31,000 miles of fossil fuel-free motoring.

Other features of the site include rainwater collection, storage and recycling. This is combined with water-efficient fittings to reduce water consumption. The retention of perimeter hedgerow, the inclusion of space for wildlife on the site and the use of sedum as a 'living' roofing material combine to maximise biodiversity. Private gardens and communal space, unusual on a high density site, good interior daylighting and high levels of soundproofing all contribute to a high quality of life for residents.

Residential consumption

Monitoring data from the Dunster-designed BedZED development, the prototype for the ZED Standards, provides a sound basis on which to estimate the consumption of the Landrake homes. Using this data we can explore the ecological footprints for future Landrake residents with reference to the South West average for residents moving into new build. To illustrate the range of lifestyles possible at Landrake, three character profiles are introduced here. They are referred to as eco-zero, eco-hero and eco-willing.

Their basic characteristics are as follows:

Eco-zero is resistant to change or subject to heavy constraints on their time, so takes the path of least resistance (real or perceived) when it comes to lifestyle choices. For example, Eco-zero will typically use a car – rather than public transport – but would probably use an electric vehicle if it were at least as accessible as a conventional alternative.

Eco-hero is at the opposite end of the spectrum. Eco-hero will always make an effort to take the most sustainable course of action and considers environmental criteria when making lifestyle choices. Eco-hero would, for example, seek to reduce the need to travel when seeking a new job and would aim to use public transport even if it meant a slightly longer journey time. Eco-hero sees benefit in not owning a car and is likely to belong to a car club – where these exist – to be able to hire one when necessary.

Eco-willing fits somewhere between zero and hero. Eco-willing is responsible but not well informed about sustainability issues, so does not consider these when making major lifestyle decisions. However, in a particular situation, if informed as to the most environmentally-friendly option, Eco-willing will generally comply even if this means some additional effort. For example, Eco-willing would not consider access by public transport when seeking a new job but once in the job, would use public transport if it were available. However, Eco-willing is more likely than Eco-zero to be drawn to the idea of car-sharing or a car club, though would probably retain their own car for occasional use.

Table 9
Landrake case study lifestyles
 
  Eco Zero Eco Hero Eco Willing
Diet Average UK diet Vegetarian Low meat
% local/unprocessed/ fresh food 25% 50% - takes advantage of on-site allotments and box scheme 25%
Commuting 125 vehicle km per week commuting to Plymouth/Liskeard by car Works from home or lives within commuting distance by bike or electric pool car (powered by renewable energy) 125 passenger km by bus each week commuting to Plymouth/Liskeard
Holiday 1 long haul air flight per year (10,000km) European holiday by train (1,500km) 1 short haul air flight per year (2,000km)
Other travel 50 additional car km per week. 25 additional bus and 25 additional train passenger km per week 25 car km per week using electric pool car & 25 car km using own car
Domestic energy use 856kWh (from wind energy) based on 2,800kWh per dwelling at average occupancy of 3.4 people per house. Hot water: 356 kWh (50% provided by solar water heating, 50% by wood fuel). As per eco-zero As per eco-zero
Domestic waste 8kg/wk (c. UK average) no recycling 4kg/wk – 63% recycling/composting 8kg/wk (c. UK average) – 31% recycling/ composting
Spending on services £219/month £175/month £219/month
Carbon Dioxide emissions (tonnes per year) 12.1 3.2 7.5
Annual ecological footprint (gha) 6.44 2.11 3.97
 
 

* Massively constructed buildings store heat during the day for slow release at night (or over even longer periods) to minimise the need for supplementary heating. Absorbing heat in this way can also reduce overheating on hot days