CONSIDER YOUR CLIMATE
When designing your home, taking into consideration your climate zone can result in significant savings. Working with the climate and a passive design will reduce the need for excessive heating and cooling. There are eight climate zones as defined by the Building Code of Australia (BCA), which was created by using Bureau of Meteorology climatic data.
Climate zone 1 – High humidity summer, warm winter
Climate zone 2 – Warm humid summer, mild winter
Climate zone 3 – Hot dry summer, warm winter
Climate zone 4 – Hot dry summer, cool winter
Climate zone 5 – Warm temperate
Climate zone 6 – Mild temperate
Climate zone 7 – Cool temperate
Climate zone 8 – Alpine
WHAT’S WHAT WITH WINDOWS?
What is a U-value and SHGC when it comes to researching windows?
U-value is the overall heat transfer measurement through the window and is calculated under standardised conditions. A lower U-value is better at reducing heat transfer. The U-value can be determined by the glass, frame or both the glass and the frame together which is referred to as the System U-Value.
SHGC (solar heat gains coefficient) refers to how efficient a window blocks heat from the sun. The lower the window’s SHGC the less solar heat it transmits which is ideal for hot climates. A high SHGC will be more suitable for capturing the solar heat gains in colder climates.
For further information, check out the Window Energy Rating Scheme (WERS) website.
PLAN THE LAYOUT OF YOUR HOME TO BE MORE SUSTAINABLE
The rooms in your home are used for various purposes throughout the day, and the position of these rooms will relate to the comfort levels of the occupants, and the overall energy efficiency of the home.
Here are a few suggestions to get it right during the drafting phase:
Group rooms together in zones
- Kitchen and Living to the north
- Bedrooms towards the east or north
- Utilities (bath, wc, laundry) to the west or south
- Garages on the east, west or south
- Avoid north-facing courtyards and alfrescos
- Place windows for optimal cross flow ventilation
- Large open plan living areas often result in heating unused areas. You can keep the open plan aesthetic by using glass or bi-fold doors.
- Place doors at the base of stairs and avoid open stairways
- Keep ceilings low (2.7m) rather than high cathedral ceilings
- Create airlocks at external doors
CHOOSING YOUR SITE FOR ENERGY EFFICIENCY
Five tips for getting the best block:
- When purchasing land, the block should be orientated to allow you to build the living zones with major windows to the north
- Inappropriate orientation can be costly due to additional expenses in increased insulation and double glazing required to achieve the energy efficient standard
- Take advantage of as much winter sun as possible. Watch out for overshadowing building, large trees, fences or other obstructions to the north
- Obstructions to the north can cast shadows two to three times their height in mid-winter. A distance of at least 5.5m from a single storey or at least ten metres from a double story obstruction is recommended
- Avoid building garages and other buildings on the north side of the block
VICTORIAN AUDITOR GENERAL’S OFFICE REPORT – COMPLIANCE WITH BUILDING PERMITS
After attending two industry events in two weeks, and both speakers mentioning the findings in the Victoria Auditor-General’s Report on Compliance with Building Permits, and the relevance of the report to Thermal Performance Assessors (energy raters), I have read the report with great interest.
In summary, there is doubt that the building permit system is working effectively and that building surveyors are effectively satisfying their role to uphold and enforce minimum building and safety standards.
How does this affect the energy rating reports that we produce? Well, after the reports are complete we are of the understanding that the building surveyors who are on site, are checking that our stated requirements are being met during construction.
It’s our responsibility to ensure that all set of plans we endorse with our stamp have all the required information, including the R-values of insulation, window types and any other conditions we place on the dwelling to achieve the 6-Star rating.
For further information see the report in detail: VAGO – Compliance with Building Permits
COMPULSORY 6 STAR ENERGY RATING INTRODUCED
Introduced on 1 May 2011, all new homes, extensions and major renovations will need to comply with a 6 Star Energy Rating. Building works which don’t require a building permit will not be affected by the new regulations.
The 6 Star energy rating applies to the thermal performance of the building envelope including the roof, walls, floor and windows.
Recommended conditions to achieve 6-Star include:
- Orientation with the living areas to the north
- Insulation to walls and ceiling
- High performance windows
- Avoid alfresco will large windows and eaves
- Draught sealed doors
6 Star homes are projected to use 24 per cent less energy through heating and cooling compared to 5 Star homes.
For more information, visit the Building Commission