Owners, developers and contractors will be aware that contracts for the design and construction of building elements such as mechanical systems (eg. air conditioning and ventilation) typically nominate design requirements and performance standards (capacity, temperature and humidity tolerances) in accordance with the National Construction Code (NCC), and contractors provide warranties and performance guarantees in respect of design and the installation of the system.
Design requirements and performance standards are more likely to be compromised when variations resulting in design changes occur on the run. In the current environment of supply chain disruption, product and material shortages, design changes may occur more frequently as nominated components and products may be in short supply and alternatives adopted.
Unless properly implemented, the impact of such design changes are not apparent until completion or during commissioning of the installed system. By this time, where design deficiencies arise, finger pointing commonly occurs between designers and contractors as to who is at fault. Statutory protections in NSW provide guidance on how to better manage these risks upfront.
Where design changes are made on the run in NSW to class 2 – multi-storey residential apartment buildings, the Design & Building Practitioner Act 2020 (NSW) (Act) requires design changes to be prepared and certified as compliant by registered design practitioners (Architects or Engineers) prior to any variation work commencing.
The certifying design practitioner must be registered in the appropriate class. In the case of air conditioning and ventilation systems, a mechanical engineering class registration.
Section 20 of the Act deals with variations after commencement (i.e. design changes on the run) and requires that, before any variation work commences, contractors (including those down the chain) ensure any change to a regulated design is prepared by a registered design practitioner of the appropriate class and supported by a design compliance declaration stating that it complies or is otherwise consistent with the NCC.
If appointed, the same declaration must be obtained from a registered principal design practitioner. These documents must be lodged on the NSW Planning Portal no later than 1 day after commencing the variation work.
Although the Act has confined operation in NSW, key features of that regime may be adopted in design and construct contracts and subcontracts in other states and territories.
For example, contracts may provide that prior to the approval of any variation and before work commences, design changes (including new or alternative building products) be prepared by a qualified independent consultant (i.e. registered in the relevant class) and be accompanied by a statement of design compliance to be approved and verified by equivalent consultants engaged by parties up the contractual chain.
Contractors should also seek warranties and certification of design and product compliance in respect of these changes from their consultants under their consultancy agreements.
This way parties are better positioned to manage design changes on the run and limit finger pointing during commissioning when time for troubleshooting runs short. Troy Legal offers expert contracting advice to developers, owners, contractors and consultants throughout the contractual chain. Contact julian@troylegal.com.au for more information.
