These days house plans submitted to council must meet a minimum four-star energy rating to pass go. While this sounds daunting, our resident expert is here to help. For best results, start with a block of land that allows for living spaces facing north, then follow Jan Brandjes’ top 10 tips for a sustainable new home.
A seasoned construction and building specialist, Jan Brandjes, possesses years of experience in sustainable and eco-living. He is a regular contributor to publications including the home improvement pages of Melbourne paper The Herald Sun.
One: get planning
Sketch the house plan, placing living spaces such as the kitchen, dining and lounge rooms to the north, and utility areas and bedrooms to the south. This ensures living spaces benefit from the winter sun and the bedrooms stay cool in summer.
Two: think seasonal
Always consider how summer and winter will impact on the house. How will your design deal with the hot summer sun? And how will it handle cold winter winds? Make sure you have external shading on the north side to protect interior living areas from the harsh summer sun. This will still allow the winter sun into your house when it starts to become dreary indoors as well as outside. It will also reduce the amount of artificial light needed indoors in winter.
Three: focus on windows and rooves
Once you have created a floor plan, recruit an architect or building designer to create the look. A good design shows all four elevations – north, west, south and east – including the size of the windows. Keep south and west windows small; small south facing windows will reduce energy loss in the winter, while small west facing windows reduce heat gain in summer. East windows allow the morning sun to enter the house and should be average-sized windows, roughly 2 to 2.5 square metres in surface area. Larger windows on the north side are good, but they will need appropriate shading for the summer months, including generously sized eaves to provide shade in summer. When choosing a roof, remember dark colours absorb heat, while light colours reflect it. Lightweight steel roofs need less timber, while heavy tiled roofs need more timber for support.
Four: Build on solid foundations
The fall of the building block and the type of soil will play a big part in deciding the type of foundation for your house. A flat block will allow for a concrete slab, which will give you good thermal storage and less heat loss from the building. If a block has a considerable slope, a strip footing and stumps are the best solution for the house. However this type of foundation will need floor insulation and special attention to sealing of gaps and cracks.
Five: Seal the envelope.
The structure of a house comprises external walls, the ceiling and the floor and is also ; called the ‘building envelope’. If you are serious about conserving energy, you must make sure this envelope is sealed. There are plenty of holes, gaps and cracks in a house, so, before plastering, seal them and prevent unnecessary energy loss from the house. Other energy-efficient measures, such as double glazing and insulation, also have reduced impact if the house has unsealed holes and openings. An added bonus for a well-sealed building is less dust and insects entering the house.
Six: Glaze over
Double-glazed windows are a good investment for energy efficiency and they also allow for better noise control, while a variety of films and coatings are available to increase their energy efficiency. Double-glazed windows/doors are an expensive item, so do your homework and bear in mind that the long-term savings should be considered favourably against the initial cost.
Seven: No renovation without insulation
Insulation includes batts, reflective foils, blow-in or sheet insulation. Foils reflect outside heat in summer and, to a certain degree, heat from the house in winter. Batts and blow-in insulation form a barrier against cold, as well as heat, through the air they trap. The more still air the product can hold, the better it will perform. Whatever insulation you choose, make sure it is installed correctly, as any gaps or holes in the insulation barrier could result in air leakage and energy loss.
Eight: Heating, cooling, solar and fresh air
If you have followed the preceding steps to plan, then you will need very little heat in winter or cooling in summer. With the money saved from heating and cooling, you can think of installing a solar hot water system, which is extremely energy efficient and has a less than five-year payback. If your budget allows for it, consider a mechanical ventilation system for the entire house. In a well sealed house, this system will provide fresh, filtered air year round with a minimal loss of energy. It is also effective in reducing humidity, which in turn controls dust mites and mould growth.
Nine: choose healthy products
If indoor air quality is an issue, look at some “healthier” building products, which contain fewer or no chemicals. All products release chemicals in the atmosphere and have an impact on the environment. Avoid products with high formaldehyde content found in many fabrics, carpets and wood composite products and introduce hard surfaces in your house design – tiles and hardwood floors are easier to clean and dust mites don’t like them.
Ten: Water conservation
In the wake of water restrictions, we’re all increasingly aware of the need to conserve water. You can start with low-flush toilets and water saving taps and follow up with a good-sized rainwater tank. Look at the use of a grey water recycling system for the garden. By including water-saving systems at the design stage, you can reduce plumbing costs and make installation easier. Finally, plan a drought-proof garden with hardy plants, minimised grassy areas and lots of mulch to assist in retaining water.