A Holistic Approach
architecture Barnes Collie Fischer are strong believers in sustainable development when it comes to building design and construction. Adopting a sustainable development approach means embracing environmentally responsible and resource-efficient practices throughout a building's life-cycle - from siting to design, construction, operation, maintenance, renovation and demolition. The result is not only a financial saving for the owner through reducing lighting and heating costs, but also represents a first crucial step towards lowering greenhouse gas emissions. Set out on this page are some of our thoughts, practices and advice on this matter. We would be delighted to discuss any of them in more detail.
Insolation is a measure of solar radiation energy received on a given surface area and recorded during a given time. By making good use of building orientation in order to maximise daylight it is possible to increase insolation and bring daylight right into the heart of your house. This in turn minimises the use of artificial light during the daytime. Orientate your house with principal rooms facing due south (or within thirty degrees of south) to receive maximum solar gain during winter.
Nature can be used to improve insolation. Planting deciduous trees in front of south facing windows, for example, will allow sunlight through in winter when the branches are bare, yet give shade and filter the sunlight in summer when the trees are in full leaf.
Before thinking about heating the house, think about its INSULATION. Adding extra insulation can cost very little and pays back the investment quickly by saving heating costs (and goes on saving every year after it has paid for itself). Put 300 – 450 mm (12 – 18 inches) of insulation in the loft space for maximum effect and add insulation in walls and floors wherever you can.
Choose insulation on the basis of lowest EMBODIED ENERGY, i.e. the energy used to extract raw materials and the process of manufacture. Lowest embodied energy would be straw bales which are simply harvested and baled (locally). Next, sheep's wool, which is a by‐product of the woollen industry and requires only treatment against insect/vermin attack and a fire retardant – plus the "material miles" of transport form the Scottish borders. Compare this with plastic based products whose extraction and manufacture consume large quantities of energy, whose manufacture releases toxic by‐products into the environment and which, in a fire, release acrid and poisonous fumes.
Notice how a granite wall that has been in the sun all day radiates heat in the evening. It is said to have thermal inertia. Buildings should have some mass such as concrete floors or masonry walls (inside the insulation layer) to store energy. These are warmed by the sun or by the building's heating system and then re‐radiate that energy to warm the space after the sun has set or the heating has been switched off. This helps to even out the peaks and troughs of a heating cycle.
Space Heating and Ventilation: Choice of fuel
Petroleum based product are becoming scarcer and will cost more in future. Whether it is oil and LPG (liquid petroleum gas) for heating or petrol and diesel for transport, fossil fuels are finite resources that cannot be renewed. It is important, therefore, when replacing existing systems to choose an energy efficient boiler (see www.boilers.org.uk).
Burning coal produces large quantities of carbon dioxide
Electricity is generated by nuclear and fossil fuels with only a small proportion currently derived from hydro‐electric and wind generators.
An alternative is Low and Zero Carbon Technologies, which produce little or no carbon dioxide in the process of heating our homes. Examples are:
- Biomass heating systems that comprise a stove or boiler burning wood waste or other fuel grown as a crop, supplying space heating and hot water.
- Air and ground source heat pumps extract the ambient heat energy from the air or the ground around buildings and transfer it to the heating medium inside the house, ideally underfloor heating pipes. Some systems can be reversed in summer to provide cooling.
- Heat recovery ventilation involves the exchanging of heat from warm extracted air into fresh incoming air using a heat exchanger. These can recover up to seventy percent of the extracted heat and therefore significantly reduce heating bills and carbon dioxide emissions.
- Solar thermal collectors harness heat direct from the sun to heat our domestic hot water. The system comprises roof mounted solar collectors through which a medium (water or oil) is circulated and directed to a heat exchanger in the hot water cylinder.
- Photovoltaics are materials capable of converting daylight into direct current electricity. They provide renewable energy from an abundant source: the sun.
- Wind turbines convert the power in the wind into electrical energy using rotating blades that drive a generator.
Water Conservation – Rainwater Harvesting
Only one percent of water on our blue planet is suitable for drinking and yet we flush one third of this scarce resource down the toilet. As we start to come to terms with the impact of climate change, water conservation is increasingly moving up the environmental agenda. Inevitably, the cost of using water will rise and we need to change the way we think about and use water.
Jersey has limited water resources, relying entirely on the rain that falls on our forty-eight square miles and limited storage whereas Guernsey has three times the storage capacity of Jersey. In summer, twenty-five percent of demand is for garden watering. Rainwater can be collected as it runs off roofs and stored for reuse for garden watering and flushing toilets.