Section J compliance: DTS vs J1V3 FAQs

Navigating energy efficiency compliance for commercial and non-residential buildings?

Here’s what you need to know about the two main pathways: Section J (Deemed-to-Satisfy) and J1V3 (Performance Solution).

What is Section J?

Section J of the NCC (National Construction Code), sets the minimum energy efficiency requirements for non-residential buildings, including:

  • Offices
  • Warehouses
  • Retail
  • Factories
  • Child Care Centres
  • Medical Centres
  • Schools
  • Class 3 residential buildings*

* Class 3 includes Student Accommodation, Special Disability Accommodation (SDA), Serviced Apartments, Workers' Accommodation and Hotels, Motels and Hostels.

What is the Section J DTS method of compliance?

Section J contain elemental Deemed-to-Satisfy (DTS) provisions which are a prescriptive. You simply follow set requirements and calculations for each element within the proposed building:

  • Insulation levels to building fabric elements (walls, ceilings, roofs and floors)
  • Size and performance of roof lights/skylights
  • Roof colour
  • Glazing performance
  • Building sealing
  • Lighting
  • HVAC
  • Electrical

Pros:

  • Clear, straightforward compliance path
  • Suitable for simpler designs
  • May be faster and lower-cost for standard projects

Cons:

  • Less design flexibility, e.g. 5% maximum roof light area, light coloured roofs
  • Can be restrictive for achieving higher performance
  • May result in over-specification in complex buildings

What is J1V3?

J1V3 (previously known as JV3) is a performance-based compliance method, specifically it is a verification method using a reference building.

Instead of following prescriptive tables, your design is modelled in energy simulation software to demonstrate that the building’s performance meets or exceeds a benchmark reference building. The reference building is a building almost identical to yours which is DTS compliant. To be compliant the energy model must show that the proposed building does not use more energy, or create more greenhouse emissions than the reference building, according to modelling rules set out in the NCC.

Pros:

  • Much greater design flexibility
  • Can incorporate on-site renewables to offset non-compliant elements
  • Can reduce construction costs, in some case by a large margin

Cons:

  • Requires specialised and expensive modelling software
  • More detailed documentation and assessment
  • Takes more time than the DTS method, therefore costs more

When should I consider J1V3 for my project

Previously, the DTS method was considered the go-to method and JV3, as it was called then, was only considered if the DTS method was failing, as the cost of JV3 modelling was very high relative to DTS, and the DTS method was able to provide compliance using reasonably feasible construction specs in most cases.

Since NCC 2019, the stringency of the DTS method has increased, resulting in required specifications that are less likely to be feasible and more likely to add to the construction costs.

In addition, breakthrough techniques and efficiency gains have led to a reduction in the cost differential between J1V3 and DTS. As a result, in our practice, for the majority of projects, J1V3 has become the go-to tool. The relatively small additional cost in modelling is often far outweighed by the more feasible construction specifications which a J1V3 assessment provides.

What can J1V3 modelling mean for my project?

In a word: flexibility.

J1V3 modelling will often result in the ability to avoid:

  • Expensive glazing treatments such as thermally broken double glazing
  • Expensive under slab insulation
  • Being limited to light coloured roofs
  • Being forced to reduce glazing or roof light area

Who can prepare a J1V3 assessment?

Qualified energy assessors, consultants, or engineers.

How can EcoResults help?

At EcoResults, we will help you decide which pathway best suits your project. We have a great team of energy modellers, ESD engineers and consultants who will tailor our advice to meet your objectives and project requirements.

Whichever the method, our responsive and helpful consultants will work with you collaboratively, to make sure your documentation is clear and approval-ready, without adding unnecessarily to the construction cost.

What our customers say

"Would highly recommend EcoResults for someone looking to get an ESD report done. Highly efficient and provides realistic outcomes that are economical for the clients." - MKM Building Group

"Great team to work with. Responsive and know their stuff!" - COBILD

"Highly Professional Service!" - PDS Deloitte

Need advice or a quote for your next project?

Contact us so we can make your Section J compliance as simple and easy as possible.