What does the future look like if we move toward using performance-based solutions and away from the Deemed-to-Satisfy approach?
Current building design and construction methods are based on the age-old tradition of onsite manufacture by qualified tradespeople. These tradespeople are trained in the art of construction and the skills of their trade. They then apply design codes and standards during the construction process to ensure the building or structure is compliant with state legislation and all relevant building codes and standards.
During the process of construction, a building certifier or surveyor will perform inspections and check certain aspects of the construction to make sure things are compliant. The “bones” of the building are bare, which allows for the inspections to occur and the inspector to view how things have been made and their relationship to other items within the fabric of the building.
Looking at the some of the current trends, we can see that a house or building of the very near future will be manufactured off site, and made of integrated components that are structural. They will be made to order in non-standard sizing, materials and methods, they may not have foundations, and they will be made with electrical systems that are 12V DC based and hence do not need to be complied against current standards. They will be self-sufficient, be highly energy efficient and often not connected into the existing infrastructure.
These prefabricated buildings can be built to meet all legislative requirements. However, as they will be fully finished before arriving on site, not all items can be site inspected as per current methods. Also, not all materials will be visible or distinguishable and the actual construction, or how it is made, will not be visible in the final product. How do we assess these construction methods using the Deemed-to-Satisfy (DtS) system that is focused on the old methods of construction?
Performance-based solutions must be developed to address this rapidly changing construction landscape. The JV3 energy performance methodology, where a computerised model is used to predict a comparison between performance of a DtS building and a proposed building, is a current verification method. Similar methods must be developed and used for prefabrication and offsite construction. It will not be possible to use the current DtS methods to ensure compliance with modular construction, 3D printed buildings, or buildings constructed using many of the other new methods mentioned earlier.
Quality of construction, consistency and accuracy is much greater using prefabricated methods and factory manufacture and assembly. These improvements in our built environment are only possible if we break from traditional site-based methods and employ an alternative compliance pathway to the DtS solutions. We can already see the difference prefabricated trusses and framing have made to the industry and the speed of housing construction. The future is a rapid expansion of this one simple methodology into all aspects of building.
It is imperative that we continue to embrace performance-based solutions and methodologies to allow the industry the required technical scope to investigate, develop and innovate into the near future, as the old methods are becoming too expensive and time consuming to meet our increasing demands and needs within modern society.