Illustration: Lyndal Chase

1. Plastic products. Imagine future generations looking back at us and saying, You actually burnt fossil fuels and then turned them into toxic stuff that was designed to be thrown away?
2. Big Western windows with no shading or protection — the eco-house equivalent of black underwear under a white outfit. Not a good look when you are trying to keep a house cool in the late afternoon in summer, (especially kid’s bedrooms!). Keep in mind by the year 2020 air-conditioning will be a luxury that was probably dropped off the household budget years ago. If you already have large western windows, look at vertical shading (screens) or vegetation to shade them or replace with smaller windows, (and heavily insulate the wall while you are at it).
3. Air-conditioning. It will probably become cost prohibitive long before it becomes unfashionable, but at some point in our future evolution, we’ll appreciate the health benefits of natural heating and cooling without the cost.
4. Facing the˜view, or the street, rather than northern orientation. How many houses have you been to with large windows to the east or west because that’s where the view is? Bet no-one sits in those rooms to admire the view for long in summer. As Christopher Alexander said in A Pattern Language, what’s wrong with little windows in unusual places that give you a glimpse of something fantastic outside? It actually builds a sense of expectation and transition as you move through a house.
5. Double car garages. Self explanatory really. As we move into an era of diminished car use in favour of public transport it seems almost impossible to think we’re still giving preference to the good ole double garage that is often a home for junk, not cars.
6. Up-sized houses. In the same way that large vehicles are copping a bit of flack now, small homes will be beautiful one day especially when they equate to less running costs, less cleaning and more free time!
7. Lawns and other non-productive gardens. I can see a time when it will be very uncool to spend the weekend on ride-on mowers, Jamie Durie-type-makeovers will have died an un-natural death, and gardens that don’t actually do anything (i.e produce food) will be seen as a bit of a liability, as large scale agriculture and supermarket foods start to suffer. And large paved and concreted areas bouncing heat up into the house? What were we thinking?
8. Hidden solar panels and tanks. Rather than being tucked away as an eyesore, these must-haves will be worn loud and proud one day. Bling for your house.
9. Black roofs: the little black dress of house design. Now really, do I actually need to explain why dark roofs are a bad idea? Yes, we can insulate and vent and air-condition our homes to within an inch of their life, to compensate, but a simple choice of a more reflective colour, is going to save us the additional work and cost.
10. And the fashion faux pas to end all red carpet disasters: bad eaves design. I’ve had three people in the last week tell me how they can’t open their windows when it’s raining (in summer, when you want to), or that they have unliveable rooms during summer etc, etc.

One day we will all demand homes that are designed for our local climate, and what the sun and winds are doing around us. So there you have it: my Top Ten. I actually have a Top One Hundred if truth be known, but you have to start somewhere.

This article gives three very basic starting points for good passive design.

1. Orientation
2. Floor plan
3. Eaves and windows

A good builder or designer will be able to alter a standard design or juggle the orientation and layout to suit awkward blocks so these basic principles are met.

1. Orientation

The golden rule of passive design is “face the sun, not the street”. This means lining up your floor plan so that the long axis runs East-West with your living areas facing true north, wherever possible (true north varies for every location in Australia, and on the Sunshine Coast is about 10.50 west of magnetic north. Note: compasses indicate magnetic north). This is an important distinction, as it is the ‘true’ axis of the sun’s yearly movement through our sky.

What a long east-west axis does, is make the ‘short’ walls of the house face east and west, where the sun hangs low in the sky, in the early morning and late afternoon in summer. By heavily insulating and shading these short walls with external screens or plants, and by having few windows, the inside of the building is protected from heat gain during the warmer months. (If you have children’s bedrooms facing west with large windows and minimal shading, you are already experiencing the effect of bad design during summer – kids, early bedtimes and hot rooms don’t mix well).

Secondly, you cluster living areas to true north, so that the sun can be used to warm the most used spaces during winter and shaded out in summer. If your block does not allow a long east-west axis, it’s important to reorganise the floor plan so that your main living areas have glazed windows or doors facing true north, with correctly sized eaves, to achieve the same effect. (See following sections).

More info: Case Study 7.1 Modifying a Project Home is a great example of how a few minor changes to a basic plan can make huge improvements to how the home works.

2. Floor plan

Designing a plan that is ideally one-room wide throughout, or with operable or louvred internal walls, allows breezes to cross from one side of the building to the other and cool and ventilate rooms naturally. Like water, air likes to take the most direct path, so for good cross ventilation, you should place openings directly opposite each other. A window in one wall, without a corresponding opening opposite, won’t do a lot to draw air through the room.

Cluster living areas that need heating in winter, to the north, and use ‘utility’ rooms such as the laundry, garage and bathrooms in the southeast and southwest corners to buffer the hot morning and afternoon sun in
summer. Obviously this is a very prescriptive approach – there are a million ways to design spaces that perform these same basic functions.

3. Eaves and Windows

On the Sunshine Coast, eaves that sit out roughly half the distance of the height of the glazed area below them on the northern side of the building, will allow warming sun into the living areas during winter months when its travelling low in the sky, and keep it out during summer when its passing higher overhead. Coupled with good roof insulation and deciduous trees or vines on a pergola across the north face of the house, the right sized eaves will maximise the natural heating and cooling of internal spaces without the need for mechanical systems.

Glazed areas (windows and doors) should ideally be equal in area to about a fifth of the floor area of the room they are located in, on the northern face. This way during winter, enough sun will be allowed into a room to effectively heat it.

Ample eaves over windows will also allow windows to be open during storms in hot months, when ventilation is important.

Short east and western walls should have as few windows as possible (other than small ones to facilitate cross ventilation) and be shaded all year round, either with vertical shutters, screens, or vegetation.

Southern windows should be kept to a minimum, to avoid too much heat loss during Winter (from the shaded, cold side of building) – again, just enough to provide good cross ventilation.

When choosing windows for the side/s of the house that receive the cooling summer breezes, (usually northeast to southeast) think about side-hung or pivoting window frames that will act as a funnel or sail, to catch breezes and direct them into the house, rather than sliders (that cut off half the area to breeze) or louvres (effective, but only open straight-on from the wall – and they don’t have the ‘funnelling’ effect).

There are literally hundreds of small things you can do to manipulate sun and air movement around a home and make a massive improvement on its energy requirements.

For more detailed information, visit the yourhome website or get weekly eco-design tips by email from Jo’s website by clicking here.