Overview
As a member of the Alternative Technology Association www.ata.org.au and an organiser of Sustainable House Day www.sustainablehouseday.com I often hear the question: ‘I want to do something but where do I start?’
Many people are enthused by what they see at events such as Sustainable House Day. They see homes that are warm in winter and cool in summer without reliance on energy greedy heating and cooling systems. They gather rainfall and greywater and use these to supply wonderful food producing, water efficient gardens. The problem is that visitors only see the finished home, hopefully working well and with owners that are enthusiastic about their creation and keen to encourage others to do the same. Time doesn’t usually allow visitors to ask the owners about how they went through the whole saga of planning and creating a sustainable home. The wondering, the indecision, the frustration and the many stages of learning they had to go through.
This article is intended as a starting point for anyone who wants to build a new home or renovate an existing building with a focus on sustainable living. There are many other people who’ve been through this process and are far better qualified to give guidance and I encourage them to add comments or email me with suggestions. Eventually we’ll develop a complete resource that will outline the learning, planning, designing, building and management of a sustainable home. The more you learn before you start, the easier the process will be and there’s less likelihood of repeating the mistakes that others have made before you.
Everything mentioned in this short overview, and a lot more besides, is detailed in Your Home Technical Manual (YHTM) which is a comprehensive guide to all aspects of sustainable housing. Don’t be put off by the ‘technical manual’ in the title. It suits all levels of expertise from someone who needs a starting point to someone who wants to learn the finer points of window tinting. It’s particularly inspirational with walk-throughs of some excellent examples of sustainable homes. It’s available on-line via http://www.yourhome.gov.au or in print form from the Alternative Technology Association via http://www.ata.org.au. However YHTM is 350 pages long and reading it cover to cover would be a daunting task if you were just looking for some initial guidance. If you can access a copy or have downloaded it, check the relevant headings in YHTM as they’re dealt with in this article.
The process of creating a sustainable home involves the following steps. These aren’t strictly sequential but are in a roughly logical order:
Decide what you want to do - build or renovate
Find out what others have done
Outline your needs
Lean the concepts
The design process
Find a builder
Manage the project
Manage the home
Think about what you'd like to do:
Buy a block of land and build your ideal home
Purchase an existing home and modify it for energy efficiency
Modify your own home for energy efficiency
Buy a block and build
This has the advantage that you should have a free choice about orientation. This may be constrained by local regulations but you want to ensure a good northerly aspect to allow good passive solar design and mounting of solar electric and water heating panels. You also want to make the best of any view.
If this is your dream, where do you want to live? Will you need to travel to work? Remember that travelling is a component in overall sustainability. You might build your dream energy efficient home in the country, paying little on heating and cooling - only to spend the savings on travelling to work.
Microclimates vary considerably over a fairly small area. Temperatures and average rainfall can vary according to elevation, proximity to the sea, prevailing winds and other factors. If you want land to cultivate, do some research on the area before setting your heart on it.
Consider the proximity to mains power, water supply and sewerage. Do you want a solar power system that’s connected to the electrical grid? Or do you want to generate your power from sun and wind with no reliance on the grid. Do you want to be independent of the water supply main or remain connected in case you run short? Do you want to be connected to the sewerage system or treat and re-use all your blackwater (toilet) and greywater (other wastewater)? If you’re not connected to mains electricity, mains water or sewerage system you’ll avoid the supply charges that service providers regularly increase. If you are connected, no matter how much solar electricity you generate or rainfall you catch, the suppliers will still charge you for something you may never use.
A design can allow future enhancements to be made as cheaply as possible when you can afford them without re-work or extensive modifications. These include deep ceiling joists to accommodate an extra layer of insulation batts, foundations that will support an internal thermal mass wall and plumbing that will allow a solar heater to be easily fitted. Some builders are already producing designs that allow this and marketing them as ‘green or ‘eco’ although you might find the base price does not include the enhancements.
If you want to build a new house and wish to take a slightly simpler approach than engaging a specialised designer, it’s possible to modify a builder’s standard project home design. You possibly can’t have reverse brick veneer or an extra 50 mm of wall insulation but there is usually some flexibility to improve performance. This includes orientation so living areas face north but there may be a chance to reverse the floor plan in a mirror image and relocate rooms for better solar gain and shading.
Buy and modify an existing house
Apart from size, location to public transport and other normal selection criteria there are some energy efficiency design factors to consider. YHTM has some particularly good suggestions about these. Take care with orientation, making sure that the living areas where you’d need passive solar winter heating are north facing and not shaded by adjacent structures.
Make sure there’s sufficient unshaded north or north-west facing roof space for mounting solar panels. Check with suppliers for the area needed for this. A rough guide for solar electricity is nine square metres per kilowatt for crystalline types. Is there adequate roof area for substantial rainwater catchment and space for storage tanks? Tanks can be distributed around the building but you might want between 10,000 and 20,000 litres of storage so check available space.
Modify your own home
If you like where you live or aren’t in a situation where you can move or build then ‘love the one you’re with’. Orientation and northerly aspect are pre-set but there might be some flexibility possible depending on layout and how much you want to spend. Many of the considerations that apply to ‘Buy and modify..’ are also relevant in this case. If north facing bedrooms could be better utilised as living areas, then changing the functions of rooms might be worth considering.
Sketch a plan of your home showing the direction of north and indicate maximum areas of shading by adjacent trees and buildings. Show clearances around the house with a view to locating rainwater tanks. This will be useful when gathering your own thoughts about upgrading as well as approaching a designer. If you have a simple sketching program on your computer – there’s one in Word – this will allow you to create something that can be easily modified and emailed to designers and suppliers.
On the sketch, mark the usual direction of summer breezes and check the potential for improved cross ventilation. Can you open windows on opposite sides of the house and is there a free path for cooling breezes to flow through? The cooling value of cross ventilation is far greater than you’d gain from an air conditioner whose power is partly supplied by solar panels. It’s also free. Conduct an energy audit – see ‘Learn the concepts’. This will help you to learn about the performance of your own home and also something about effective design and constructions.
Find out what others have done
You probably know about Sustainable House Day each September - if not, check the website www.sustainablehouseday.com. In the weeks leading up to the event it contains the profiles of the homes to be opened and afterward, for the rest of the year you can still check their details. Read magazines such as Sanctuary, published by the Alternative Technology Association and check their website www.ata.org.au. Check other books, magazines and websites about sustainable living and do web searches about topics such as: sustainable house, energy efficient, house star rating, sustainable design, green house, eco design and various permutations. Look at the websites of eco designers, architects and builders to see designs of new homes and any retrofits they’ve done.
Look out for openings of homes that are advertised as energy efficient and attend them with a critical eye. There’s a lot of ‘greenwash’ around at present and many strange performance claims are made. Always check the knowledge of the sales person about terms such as thermal mass, passive solar design and embodied energy. Go inside on a bright winter’s day and if the orientation and windows are optimised for passive solar gain and insulation is adequate, the internal temperature should be comfortable without any artificial heating.
Outline your needs
Having decided on building new or renovating an existing house, what sort of place do you want? There are the usual considerations such as the number of bedrooms but what aspects of energy and water efficiency do you want? It’s possibly more complex to modify an existing house than starting with a blank sheet on a bare block.
Several homes open on Sustainable House Day were modestly sized traditional houses to which an energy efficient family room has been added. This makes sense as a lot of time is spent in the family room and it’s usually where most heating and cooling costs are incurred during the day and evening. If you’re modifying an existing building, the scope of what you can do may be limited. If it’s constructed of double brick it will not have low thermal mass outside walls. You can improve performance by adding insulation, shading and painting white but unless you fancy reconstructing the wall, the bricks will always be there. However adding a new room allows the use of appropriate design techniques such as putting thermal mass inside the house and constructing outside walls from low thermal mass materials. Other areas may not be such a concern to you. Many people like cold bedrooms so winter heating is not an issue. During summer, ceiling fans and cross ventilation often suffice in bedrooms and if it gets oppressively hot in summer you can always sleep in the family room.
Learn the concepts
This isn’t a training course on sustainable building design but a short guide to further learning. Your Home Technical Manual is a comprehensive guide to all aspects of sustainable housing. Don’t be put off by the ‘technical manual’ in the title. It suits all levels of expertise from someone who’s looking for a starting point to those who want the finer detail of window tinting. It’s particularly inspirational with walk-throughs of some excellent examples of sustainable homes. It’s available on-line via http://www.yourhome.gov.au or in print form from the Alternative Technology Association via http://www.ata.org.au. The ATA’s website also contains a lot of information about energy efficiency across a broad range of applications including building design.
Some of the topics you might like to learn about when planning to build or renovate are:
micro climate
thermal mass
wall construction
passive design
wall insulation
roof insulation
shading
cross ventilation
glazing and window treatment
rainwater catchment
embodied energy
Conduct a home energy and water audit on your existing home, no matter whether you own or rent it, or whether it’s a building you want to refurbish. An audit is just a good way to learn about how a building performs in terms of energy and water efficiency and how it could be improved. This audit will help you check where heat is lost in the winter and where unwanted heat enters in the summer. It will give an idea of how much water you use and how you could reduce consumption. In South Australia you can borrow a home audit kit free of charge from many libraries. Check for similar schemes in your state. There are also trained auditors who you can engage to conduct a home energy audit. They produce a written report about the building’s performance, identifying areas where it could be improved and suggesting practical methods for achieving this.
The design process
There are three possible approaches to design:
do it all yourself
engage a designer/architect to create the whole design to your basic requirements
engage a designer/architect to work with you.
The third option covers a range of possibilities and needs a negotiated working relationship that’s manageable and trusting. A designer’s professional reputation depends on how well his/her designs perform. They won’t compromise effective passive solar design because the owner insists on a certain orientation or huge windows just to obtain a good view of the vineyards.
Before engaging a designer:
decide your budget
outline your needs
Ensure you’ve ‘learned the concepts’ as above. Ask around. Check the names of designers and architects listed in Sustainable House Day entries or in Sanctuary and other publications. Look at their websites. Ask for to see examples of their work – plans, photos, descriptions, specifications, performance data. Talk to them about their special interests and recommendations. An introduction to a satisfied owner and a tour of their home would be ideal. Some designers are noted for their affordable designs, others for their individualistic styles and their website and examples should indicate this. Ask for a cost guideline for design and building. This is usually expressed as dollars per unit of area.
Find a builder
What are the special qualities of a builder? What’s different about building an energy efficient versus a traditional home? Some of the factors are as follows: Walls and ceilings of energy efficient homes have better insulation than traditional buildings. This usually means thicker batts so wall frames and ceiling joists need to be of larger section than usual. These are available from timber yards but some extra work is involved in cost estimation and construction.
There may be extra layers of other insulation and air gaps to be incorporated. Because walls are thicker, room dimensions may be affected and standard size wall panels may need to be cut to fit. The use of environmentally friendly adhesives, particle board bonding agents and paints means more hunting around and head scratching for the builder whose main concerns are usually structural strength and wearability. Each time the builder encounters an obstacle, there’s a delay to evaluate the alternatives and discuss with the owner. As the factors to be considered include energy efficiency, waste minimisation and eco-friendly methods and materials – as well as cost - this can become an involved process. It’s far easier for the builder to rely on previous experience and go with the quickest and cheapest solution.
There must be some understanding between owner and builder whereby the owner accepts they are imposing special conditions on the contract and is prepared to pay more for these to be met. The builder accepts that the project could take more time and must be prepared to work through problems to the owner’s satisfaction on the understanding that this will be paid for. The builder should realise that a successful outcome – a manageable house with a happy owner – will enhance their reputation as a builder of sustainable homes.
Personal recommendation is more valuable than any form of business promotion. Spending an extra hour or two solving a problem with the owner costs far less than a newspaper advert and the return in terms of extra business is far greater. So find a builder via personal recommendation if possible. Check similar sources to those mentioned for finding a designer. Check the Master Builders’ Association for a register of trained ‘eco builders’ and the Master Plumbers’ Association for ‘eco plumbers’.
Manage the project
Managing the project means converting the design into reality. This includes obtaining approvals, engaging the different trades, coordinating their activities and paying them as work progresses, nagging them if it doesn’t, solving problems, checking compliance with codes and standards and a host of other things through to practical completion. You can engage a builder who will manage the project or do it yourself.
Doing it yourself can save money or can get you into trouble and cost more money. Several SHD owners report having managed the project themselves - presumably successfully as the houses were safely opened on the day. None of these people had managed building projects before but all had gone into it in an organised, pre-planned manner. They were prepared for some give and take with tradespeople and weren’t in a mad rush to meet deadlines. Also they were ready to do some unskilled hands-on work themselves.
One owner reported that she’d developed a set of questions to check the eco-knowledge and experience of tradespeople before selecting them. After engaging them she did odd jobs such as tidying up, spreading gravel, breaking up old concrete and other tasks requiring no great skills. This created goodwill and tradespeople reciprocated by doing minor extra work free of charge.
Manage the home
Even the best designed house will perform poorly if not managed correctly. Conversely a poorly designed home can be made more liveable by better management. Managing the home to maintain a comfortable inside temperature involves making changes between seasons and making minor adjustments over the day.
Seasonal changes include erecting temporary shade over windows, fitting vent covers to prevent heat loss and pruning back vines to allow winter sun to warm walls and windows.
Daily adjustments include closing blinds before the summer sun hits the window, opening internal doors to allow cross ventilation and regulating window opening to allow air to flow out without letting hot air in. If the house was designed by a professional designer they should provide instructions for managing the house. If you did the design, managing it properly should be second nature. Be prepared to experiment to find what works and what’s a waste of time.
Conduct an energy audit (see ‘Learn the concepts’) to find out how the home is performing and whether any opportunities for improvement exist. If you can’t conduct a full audit, do what you can. At least use a thermometer to check temperatures around the room and close to the ceiling. They should be reasonably even around the room with a small increase towards the ceiling. A hot spot opposite a closed window indicates there’s radiant heat entering so fit a heavier blind or put up some external shading. If you conduct an audit and find there’s nothing to modify - you’re doing pretty well.
Add your opinion If you've been through this process - from indecision through to completion then add your experiences. The more information and encouragement that's available, the more people will take the first step to creating their own sustainable home.
Alan Strickland
(October 2009) (
