We aim to keep our carbon footprint as light as possible. There are two fundamental reasons for this: firstly, we care about the environment and wish to leave planet Earth intact for our children and grandchildren; secondly, we don’t want to be paying high energy bills.
To achieve this, our homes will need to be highly insulated and efficient in energy use. We have adopted a recognised external standard to which our homes will be certified. This is ‘Passivhaus’.
‘Passivhaus’ is the term given to ultra low energy construction standards first pioneered in Germany in the 1990‘s, but now used throughout Europe to achieve best practice in energy conservation. In technical terms, for heating we expect to use under 15 kiloWatt hours annually per square meter of floor space. This is jaw-droppingly low!
Passivhaus design includes:
- high levels of thermal insulation and the absence of thermal bridging (where heat is lost through solid elements, window frames for example, to the outside)
- highly insulated triple glazed windows and doors
- recovery of heat from the ventilation system – referred to as mechanical ventilation and heat recovery (MVHR)
- a high degree of air tightness (windows still open but only when you want them to, ie no draughts)
Different types of construction can be used to achieve these standards. We have decided on a timber-framed structure, as this is closely allied with low energy construction.
As well as keeping our energy use low, we also aim to help protect the environment by generating solar electricity where roof design allows and in our choice of building materials, such as environment-friendly paints and stains, self-coloured render that never needs painting and renewable bamboo flooring.