All residential buildings in New South Wales need to comply with the government’s BASIX building sustainability index that regulates energy efficiency. And when it comes to reviewing house plans in NSW with an assessment of the future thermal comfort, carbon footprint and water usage of a new home, there are two ways to do it in BASIX. The simulation method, or the Do-It-Yourself approach.
Despite the DIY option sounding like it could allow for a quicker and cheaper solution, this is actually not usually the case. Ian Fry, the founder of Frys Energywise, has many years of experience within the building industry and is an in-demand authority on reviewing plans via energy assessments to achieve BASIX compliance.
“DIY only allows for minimal flexibility in the type and level of insulation, building materials and window selection,” explains Ian Fry. “So this approach is really quite limiting and can often require you to add to your building costs in added thermal performance, when it may not be required when using simulation.”
“The cost of having a thermal simulation assessment completed, is usually around the same cost as needing to have one improved window, and can often be less expensive.”
Ian Fry
That’s because a simulation assessment offers the flexibility to meet the required targets without having necessarily having to improve windows. Instead, simulation modelling allows an assessor to increase the thermal performance through more cost-effective options, like increasing the level of insulation to floors, walls and the roof, before having to look at the windows as an option. The added insulation reduces the requirements for an improved window and often avoids improved windows at all. Yet this flexibility is not allowed for with DIY.
“The real facts are that the average cost of an improved window is around $400 – a similar price you would pay for an assessor for a standard family home,” explains Fry. “If a DIY assessment requires two or more improved windows the cost would be $800, so you’d pay twice as much.”
Furthermore, the DIY option is limited by BASIX to houses under 300 sq metres of no more than two-levels – with attics classed as a third level, and thus disqualifying these homes. What’s more, mezzanine areas can’t be more than 25 sq metres (including staircase voids) and the number of windows in a house can’t exceed 44.
Simulation also offers a lot more flexibility in the building materials that can be used, the type of windows, the glass used in the windows, and the level of insulation chosen. This becomes even more important when dealing with a house that does not have an ideal aspect or has a higher glass-to-wall ratio than average.
Having a new home thermally-assessed by a trained and experienced assessor can save you thousands of dollars in additional building costs – not to mention the savings that homeowners will make in cutting energy costs by having a house that is more thermally-efficient.
A trained energy assessor has experience identifying products and offering advice on design options to help meet the BASIX targets and also save you in added building costs. Another point to consider is that a BASIX which is not properly complete can lead to a rejection by councils and other certifying authorities, resulting in lengthy delays in having a home approved for construction.
The majority of new home builders now rely on the services of trained energy assessors to ensure accurate, timely and cost effective BASIX assessments. Most have now found that using the DIY method ends up being both time-consuming and costly in relation to additional construction costs, and opt instead for a simulation assessment.
Frys Energywise has a team of qualified assessors to deal with high-volume and challenging designs. The company can be contacted on (02) 9899 2825 or at comply@frysenergywise.com.au for advice and to carry out energy assessments within Australia or BASIX assessments in NSW.
