Building for the Australian Climate.
A building’s access to sunlight is one of the leading factors contributing to its thermal comfort, with the amount of direct sunlight that the building receives greatly influencing the passive heating and cooling factors. However, as the sun’s path varies seasonally, accounting for the required direct sunlight a building needs becomes difficult. The eaves of building construction can maintain great benefits if used correctly.
Figure 1shows FIFA World Cup trophy and official football (1)
Improving required sustainability targets is essential with the ever evolving field of ESD. As new innovations emerge and more cost effective and ecological beneficial methods become more common place, adding these to exiting rating systems is essential. As seen with the proposed improvements to BASIX set for 2017.
Ever growing in popularity, green roofs and green infrastructure are becoming more and more common in architectural practice, used for both their aesthetic value, reclaiming a traditionally underutilised space, as well as for their innate thermal performance qualities improving the thermal comfort of a building whilst also promoting biodiversity.
Being conscious about the amount of raw materials used in building products is a key concept when trying to design efficiently, aiming to reduce the overall embodied energy of materials. Autoclaved Aerated Concrete or as it is more commonly known AAC, is an example of a building material that aims to reduce the overall raw material requirements whilst maintaining as many of the original product's structural and functional properties. This is achieved by creating air pockets within the concrete (aeration). These pockets of air have many benefits besides just reducing the amount of materials required to manufacture it.
The BASIX assessment and NatHERS process is an ever evolving practice which requires extensive knowledge of available materials, passive heating and cooling strategies and how to design in an ecologically sustainable manner. Although to complete and sign off on the BASIX process one must be a certified assessor. The assessor’s background does not play a large role in determining their competency in assessing a building’s efficiency. Therefore, the question is raised as to who is the most qualified or most knowledgeable to be completing the BASIX assessment?
One of the most influential factors to consider when studying ecologically sustainable development, is the advantageous affect that passive cooling and heating can have on the efficiency of a home. This involves the careful selection of materials appropriate to the climate in which the building is situated, the thorough consideration of the orientation of the building to allow adequate ventilation and appropriate solar heat gain and various other factors. By considering all of these aspects the efficiency of the building can increase dramatically, whilst also drastically decreasing the cost of heating and cooling the building.
In the field of ESD, two terms which constantly appear are the U and R values of products, but what do these mean? Whether referring to insulation or glazing each product on the market has a specific either U or R value. These values refer to the thermal performance of specific products and materials and how they assist in maintaining thermal control in a building or structure. These values are an integral part of the BASIX, NatHERS and Section J process in the NCC, which require specific values to be either entered into the glazing calculator for Section J reports or specific glazing types with predetermined U and SHGC values for BASIX and NatHERS along with specific R values for insulation and building materiality.
The NCC sets a minimum acceptable thermal performance for residential dwellings by specifying a minimum 6 star rating for all new projects in Australia with the exception of NSW who are under the BASIX programme.
