Q: How can industry overcome these challenges?
PH: Firstly, we need to evaluate and make changes to relevant legislation to address shortfalls in the support of prefabrication, and sustainable housing research and development. We also need more professionals and tradespeople within industry to embrace evidence-based building practices for sustainable housing and overcome the fear of doing things differently. In doing this, businesses will have the confidence to inquire, engage and innovate.
Australia needs stronger collaboration between academia and industry. When we have our university academics and our practical tradespeople with their innovative ideas in the same room, and we have legislation and rule makers who encourages outcomes, we will have an unstoppable industry for innovation and sustainability.
Q: How does prefabrication allow you to produce sustainable buildings?
PH: Prefabrication has allowed Valley Workshop to develop a sustainable and healthy building system since building in a workshop enables us to have better quality control, less material wastage and reduce energy consumption onsite. We produce buildings with good design, hyper-insulation and condensation control. Some of the complexities of the architect’s designs would not be possible onsite in an affordable amount of time otherwise.
Q: When you say you build for condensation control, what do you mean by that?
PH: Condensation control has become a big issue in recent years in Australian buildings. Changes to the National Construction Code has mandated improved thermal efficiency. This has encouraged a number of initiatives, such as reducing the number of air movements by ‘tight’ building, and the use of insulating components such as double and triple glazing.
There have been unexpected and unwelcome side effects. Water vapour is generated from within a building by occupants breathing, cooking or showering etc. External air can have a high proportion of vapour, particularly during hot wet periods. If air that contains vapour loses temperature as it is absorbed and passes through a wall, it can reach a temperature where it can no longer hold the vapour, which condenses into solid water. This is called a dew point.
Where internal comfort is achieved by mechanical heating or cooling, and little or no natural ventilation, there is no possibility for vapour to diffuse other than by absorption into walls. In cooler climates water will condense on the coldest surface, which is usually window glass. Known as ‘crying windows’, this is unsightly, and can cause superficial damage. However, it is also a safety controller because if the vapour does not condense on windows it will do so elsewhere. With high quality double and triple glazing the glass may not be sufficiently cold enough to induce condensation. Vapour may then condense into water within the wall fabric.
This is a negative outcome; at best it will form mould, at worst it will cause rot in the structure. Evidence suggests 80 per cent of new houses in Australia suffer from some form of side effect from condensation, and 30 per cent suffer actual damage. It is Valley Workshop’s intention to construct with methods to control condensation, even though it is unlikely to be mandated in the code for some time. While increasing costs, the changes will appeal to a defined market desiring improved environmental outcomes in their new buildings.
Q: Are there any exciting projects you have worked on?
PH: Every project is exciting. Our clientele are mums and dads in the residential market. We are really lucky to have worked with some wonderful clients. We have a lot on at the moment and a lot of enquiries, particularly from mainland states.
Personally, one of the most exciting and exhausting projects I completed was the Frenchmans Cap build in Franklin Wild Rivers National Park. Working with other industry professionals, we were able to capitalise on all the years of our research and development, and home-grown Tasmanian innovation, and deliver our building systems via helicopter. The general public benefit by having access to shelter in one of the most pristine, ecological sensitive but inhospitable parts of Australia. Valley Workshop won both state and national environment and energy efficiency award for this build in 2018.
We went on to improve our systems from this build experience, and in 2019 won the Tasmanian Forest and Forestry Product Network Innovation Award as well as the 2019 HIA Tasmanian GreenSmart Sustainable Home Award.