Eco houses a good or bad idea? - 42

What is an Eco house?

The name is banded around and is ultimately misunderstood by the general public. It has also become a generic term encompassing all things ecological and sustainable in terms of building and living in an environmentally friendly home. There is actually no simple definition of an eco house and it could be said that any house which incorporates technology, such as renewable energy solutions, may be considered an eco house to a degree. Another ‘Green’ concept would be to build a house using some overtly ‘green’ material such as sheep’s wool insulation or straw bales for insulation of the external walls. The commitment to build in these greener materials indicates a strong statement in terms of the ‘greenness’ of the build but without a holistic approach to the dwelling the green opportunity of building a new dwelling may be lost.

Architect Paul McAlister

The global problem of build-up in CO2 gases in the atmosphere and the knock on effect of global warming, and damage to the ecosystem, is a manmade phenomenon which needs to be addressed for a sustainable future.

In the UK 30% of CO2 is produced as a result of the energy requirement of the housing stock, which means the homes, that we all live in, produce a significant amount of all CO2. Governments have recognised this and have a target, enforceable by building regulations, for all new homes to be carbon neutral by 2016. This would be achieved by a series of incremental increases in the energy efficiency of dwellings and the increased use of renewable technologies.

The energy efficiency of dwellings is therefore the one area in which the individual may play a major part in reducing their ‘carbon footprint’ making a contribution to reduce CO2 emissions.

An added benefit of an energy efficient home is the actual running costs of the house itself. An initial capital investment providing a super-insulated envelope for the building and suitable means of energy efficient ventilation may have a payback period of 5-10 years, depending on specification. After this period the house is saving money for the occupiers, as it is possible to design passive houses that need no additional heat source except in severe weather conditions.

If we identify energy efficiency as one of the key elements in environmentally friendly building design then it would seem appropriate to focus on this area, as a key element in the design and specification, were the correct choice of building materials and construction techniques will make a significant contribution to the home. The use of renewable energy sources also has a role to play and the investment of relatively common technology, such as solar panels for hot water heating, should be considered for any new home striving to be energy efficient.

The other element of Eco build that makes an environmental impact is reducing water supply needs by recycling of rainwater from roofs. This water is stored and reused for washing and flushing toilets whilst the waste produced from the home may be filtered by reed beds.

Finally the choice of material to construct the eco home brings more choices to be made in terms of Green materials. The concept of embodied energy, the energy required to produce the material, becomes a deciding factor and also the amount of CO2 used in the production of the material. The use of timber as a building material, from sustainable and managed forests, is an obvious ‘green’ material as the trees themselves absorb CO2 when growing. The use of recycled or natural material also has environmentally green credentials. The judgement may come to personal preference or the financial implications of some of the less mass produced products may make their use prohibitive.

In the end market forces and government legislation will determine changes in building design. There is a strong argument to future-proof new dwellings for the lifetime of the home occupier and for generations to come. This investment will ensure a sustainable future for our housing stock and makes the Eco house concept one that becomes the prudent benchmark of new homes.

Paul McAlister