The exact climate conditions surrounding the building are first to be determined (such as temperature, humidity, average irradiation, prevailing wind, wind flows and shade from other buildings or trees). The key aim is to maximise the benefit from the surrounding climate and minimise any difficulty it may bring.
Selecting the correct shape
The more the shape of the building is compacted (ratio volume / surface low), the less heat it will lose. The roof’s shape can protect the building from the wind, for example a low roof on the side of the prevailing wind or a four pitched roof to break the wind.
Utilisation of vegetation
Vegetation can be positioned effectively around the building to protect it against the elements. For example, a deciduous tree to the south will provide shade during the summer and will allow the passage of light during winter. An evergreen tree hedge can be used to block the flow of heavy wind.
Solar passive construction
Specific factors such as insulation, air tightness, thermal inertia, and ways to catch winter sun whilst avoiding summer sun.
Arrange rooms to maximize internal gain and need
- Highly insulated building with no thermal bridge: external insulation is the best way to achieve this, but also the most expensive.
- Air tightness of the building to avoid unexpected infiltration when the weather is very cold or very windy: the building should have a ventilation system to ensure a healthy air quality. It will most likely be a system with heat recovery, and can also be a passive ventilation system similar to the one developed by the Zed Factory.
- Heavy construction material should be used to avoid temperature fluctuation and to store heat (thermal inertia). Heavy masses should be set to be exposed to direct sunlight.
- North-South orientation is better than East-West to maximize solar passive gain.
- Building design to allow solar penetration: for example, running-through-room lets rays of sunshine penetrate deeply into the building, especially in winter-time. Appropriate sun shades will help keep temperatures down during summer. See cross-section (below) to observe how winter and summer sunlight penetrates the building.
- A range of different products can help capture heat and light from the sun, such as a double-skin wall, a Trombe Wall, a light reflector and sunpipes.
- Minimise windows on North and West side of building (North due to the cold and poor gains/losses ratio, West to avoid overheating in summer as the sun is low, generating light and heat towards the end of the day).
Garage, laundry room, storage room, stairs, entrance - colder rooms which are used less.
Kitchen, office or guest room - to catch the sun in the morning but not in the evening, to avoid overheating.
East/South-East or West/South-West:
Library, bedroom, music room, garden, studio - to maintain a comfortable temperature.
Living room, dining room, sunspace, winter garden - to maximise solar gain in winter.
For all buffer spaces on the north side to be efficient, insulation should be put between them and the main living space. An active buffer space (such as a sun lounge) can be set on the South side, to enhance solar gains.
Finally, an entrance airlock protects the living space from draughts occurring on entry and exit of the building.
Add technological features
- Solar photovoltaic panels or wind turbine (if appropriate location) to generate electricity.
- Solar thermal panel to generate hot water.
- Biomass boiler/CHP if a heating system is necessary.