The National Construction Code (NCC) sets out performance based design and construction standards for buildings within Australia, including minimum requirements for structure and fire safety, accessibility, services, health and amenity and energy efficiency.  The code is broken into three volumes covering commercial, residential and industrial buildings in addition to technical requirements for the design, construction and installation of plumbing and drainage systems.

Volume 1, Section J specifically sets out the performance standards relating to the energy efficiency of a building including the thermal performance of the building and efficiency of the services and systems installed. All building projects within Australia must demonstrate compliance with the code as part of the Development Approval (DA) process.

Thermal Performance (Section J 4 and 5)

The thermal performance of a building is dependent on a number of factors such as building orientation, extent of glazing, provision and positioning of shading, and building fabric selections.  Dewick & Associates are able to assist through the Design & Construct (D&C) phase of a project by providing a thermal performance NCC Section J assessment of the building for DA approval.  

Our in-house professional engineers review the architect’s plans and use a variety of energy efficiency modelling methods (JV3 or Deemed to Satisfy – whichever is most appropriate to the project) to obtain the optimum balance of aesthetics, performance and cost on behalf of our client. We ensure that the building design satisfies the applicable standards whilst also providing flexibility to facilitate the delivery of cost efficient solutions. A typical example would be glazing selection and performance where there are a number of considerations:

• An architect has a vision for a fully glazed northern facade, with a clear glazed aesthetic.
• The fully glazed facade presents excessive heat gains to the space which has adverse impacts on mechanical plant selections and energy efficiency during operation (i.e. oversized plant and excessive energy consumption) as well as compromising internal thermal comfort conditions. 
• The most cost effective solutions would be to reduce the extent of glazing or/and provide tinted glazing, although these approaches may not align with the architect’s vision.

Dewick & Associates are able to assess alternative design options, review glazing performance and balance this with the performance of the building envelope as a whole, i.e. wall and ceiling insulation, roof lights. We present some options to the design team for discussion:

• Retain all glazing but provide horizontal shading elements to cut out direct solar gain and reduce heat loads, plant size, energy consumption and improve thermal comfort conditions, without compromising natural daylight levels and views to outside.
• Utilise tinted/coloured glazing or apply a film to the glazing to reduce the glazing system Solar Heat Gain Coefficient (SHGC) and reduce the direct solar gain to the space, thereby reducing heat loads, plant size, energy consumption and improving thermal comfort conditions. Views to outside may be compromised. 
• Increase the overall thermal performance of the glazing selection(s) including the use of Double Glazing Units (DGUs) in-lieu of single glazing, reducing the glazing U-value and SHGC.
• Reduce the extent of glazing where we can advise on the extent of reduction required to provide an optimal outcome, considering all other variables;
• Assess utilising higher levels of insulation throughout external wall constructions to relax glazing U-value requirements.

Our extensive experience in this area is key to being able to find the best solution for the project by applying an iterative modelling approach. Dewick & Associates will ensure the client is provided with a cost effective complaint solution whilst remaining architecturally acceptable.

Building Services  (Section J 6,7, 8 and 9)

In addition to the thermal performance of the building, Dewick & Associates ensure that the proposed engineering services installation is fully compliant with the NCC 2022 Section J requirements. We are able to provide simple checklist based compliance reports for engineering services contractors to utilise.

Reporting Compliance

Once a compliance approach has been agreed, Dewick & Associates provides a summary of the NCC 2022 Section J compliance requirements for the project, covering the following parts of the 2022 National Construction Code (NCC) Volume 1 Section J requirements: 

• Part J4 Building Fabric
  • J4D4 – Roof and Ceiling Construction
  • J4D5 – Roof Lights
  • J4D6 – Walls and Glazing
  • J4D7 – Floors
• Part J5 Building Sealing
• Part J6 Air-conditioning and Ventilation Systems
• Part J7 Artificial Lighting and Power
• Part J8 Heated Water Supply and Swimming Pool Plant
• Part J9 Facilities for Energy Monitoring

All of our reporting is undersigned by our in-house Chartered Engineers with the following qualifications:

• MCIBSE CEng
• Victoria Registered Professional Engineer
• Practicing Registered Professional Engineer of Queensland
• NSW Professional Engineer Registration under the Design and Building Practitioners Regulations 2021.

Dewick & Associates approach to ensuring project compliance is bespoke and tailored to the specific project, reflecting client aspirations, project budget and the stage of the design. We can provide simple sign-off for a full design but are also adept at getting involved with the detail;  working through the project as a whole and achieving compliance through workshops and discussion. We understand that all projects are different and our flexible approach to compliance ensures the optimum outcome for all.

Author: Louise Gardner, General Manager of Dewick & Associates