How To Design & Build a Sustainable Home
It’s super easy. Anyone can build sustainably.
Here’s a checklist to help you
Building sustainably isn’t rocket science. Do what you can for the budget you have, what you can do yourself and what you have lying around.
Many people believe energy & water efficient fittings or plantation materials are what makes a sustainable home. That’s just one part of the mix.
Do what you can, include as many of these features as you can, so you can make a bigger impact.
How to design & build a sustainable home, easy steps
- Size, the larger the house (with less people), the less sustainable it is
- Solar passive (thermal mass and insulation) including design & materials used for best efficiency
We’ve found using thick insulation on the external walls and thermal mass for internal walls and floors give THE best results, like 9 stars out of 10 for energy efficiency (for climates that have big changes eg. cold in winter and hot in summer).
For tropical climates, having wrap around verandahs, wider eaves, vented roofs are beneficial.
- Orientation of the house to face north (sometimes north/east or north/west depending on climate). Having windows on the north/east side of a house and south for harsh summers to get sea breezes in some areas have a massive impact on the comfort of the house. Or building on the east side of a hill as opposed to the west will be better for harsh summer heat and cold westerly winds
- Surrounding vegetation, water bodies and habitat can have a positive effect on the solar passiveness of a house. Deciduous plants for blocking out harsh summer reflected heat (or having soft vegetation around a house instead of concrete or hard surfaces have a big effect. Installing wind breaks for cold winter winds will help protect the house)
- Energy efficiency: lighting, power, heating, hot water, cooling, windows, thermal, external colour of roof and walls, bridges, air gaps, penetrations in the building envelope need to be sealed
- Heating and cooling best practise: use the sun to heat you and thermal mass to lock in the heat as much as possible. Use fans, eaves and windows that allow optimum air flow to naturally cool the house. Then mechanical heating and cooling where needed (harvest your own via solar heating and solar hot water)
- Use utilities that are harvested on site if possible and go back to the grid for others to use (water, power, sewer)
- Sustainable (natural, local, reclaimed, recycled, source of materials) eg. magnesium board or bamboo products are ‘eco’ or ‘green’ at the moment. But where do they really get sourced from and what holds them together?? (Many man-made materials are sourced from overseas and held together with glues – you have no control over these)
- Environmental management (choice of materials, waste generated when building, chemicals, man-made materials used, recycling on site, power usage) in the building of the house
- Building envelope is sealed and managed for moisture, air, wind, humidity, pressure (structural and where services/penetrations are in walls, floor and roof)
- Carbon footprint and emissions in building and maintaining house. What materials are used when building. Concrete, glass, bricks all have high carbon footprints as the energy required (or emodied energy) to make them is very high. What’s the footprint needed to build the home and then heat and cool it?Carbon lifecycle of the house, you can get it rated but this involves looking at the source of materials, how much energy was used in its creation and the longevity of the product and what happens at the end of it’s life (is it waste or organic and what’s the long term effect on the planet)
- Chemicals and man-made items:
Termite systems (physical and visual barriers best practise), builder’s foam and chemicals not best practise when it comes to reducing VOCs and chemicals that workers have to deal with, insulation, heating, cooling, paints. Fibre glass batts are not great, some wool batts have redardants and chemicals on them. Try polyester /recycled plastic to reduce chemical use. Using termite treated timbers (cutting them) can be a health risk to the workers. New products come onto the market so research to find out how they are made
- The health of the occupants and workers is important. Workplace health and safety is top of our mind. Research has shown that builders have a high propensity to get health issues due to the amount of chemicals and toxins they inhale while building. In one European study, painters had a significantly greater risk of dying of cancers than any other profession due to the VOCs they inhale. Sam has chemical sensitivities due to being overexposed to chemicals. Be mindful.
- Natural/organic products are usually local, have had little processing and when it’s finished it will just go back to nature (timber, earth, sand) and break down with little long term effects on the environment
- Visual look and feel. Blending in with the surrounding environment may be important if you’re building in suburbia and your neighbours are different to you
- Not having to do big excavation (cut and fill) or create erosion issues
- Reusing an existing house and renovating to extend the life of a house is more sustainable than building brand new
- Having more occupants in a house is better than have 1 person or couple in a large house
- A sustainable house is one that is affordable (so you aren’t in big debts to build or maintain it)
- The Builder’s triangle includes Cost, Quality and Time it takes. You have to make a compromise on these because you can’t get all 3 at any one time. The environment, comfort and health are in Quality. In other words… there is always a compromise you have to make
- Electromagnetic radiation has had conflicting research results. When building biologists test the radiation in a house, there are increases in it wherever meter boxes back onto a room. Being aware of such issues and designing your home to reduce radiation. Radon gas is also a real issue
- Indoor air quality, humidity, temperature are all factors that contribute to a building that is ‘comfortable’Indoor air quality, humidity, temperature are all factors that contribute to a building that feels ‘comfortable’. When a home is stuffy, with too much indoor pressure, too dry or too humid we don’t feel good. This is how ‘sick building’ syndrome can start… the indoor air quality is too humid and the materials start to decay and break down. Mould is present often in zones where there is too much moisture and humidity