Commercial Section J Energy Report

Commercial Section J – Deemed To Satisfy (DTS) energy report provides a list of prescriptive insulation values and thermal performance requirements in order for a commercial building to comply with the construction code. Section J of the National Construction Code (NCC Vol. 1), or as it was formerly known, the Building Code of Australia (BCA), applies to all commercial buildings.
The Section J – DTS report is the minimum required standard to ensure energy efficiency compliance of your building to the code. It is simple, low cost, and can usually be delivered in 1 to 2 business days.

Get a free quote today!

What is covered in a Section J – DtS report

Australia’s building codes seek to minimize the energy demand of commercial built spaces to minimize their carbon footprint.

The core of a Section J – DTS report, is a short table that outlines the minimum applicable thermal performance parameters – mainly to the building fabric and building services. This information is the minimum required for compliance, but architects and builders can benefit from additional information being supplied to make their jobs faster and easier. DTS pathway is also the cheapest pathway while undertaking alterations/additions to your existing building.

Although this is a typical extract of selected building classification, it shows how NCC DTS Performance Requirement works. For example, extremely hot or extremely cold climates are more insulation demanding. Considering building classification, Class 3, 9a & 9c demand more insulation on the walls with minor glazing (less than 20% of the total wall-glazing area) and less solar admittance through windows.
Below is a sample extract of the DTS requirements for an Office – Class 5 building in Climate zones 5 and 6. Read more on building classifications here.

WHY AUSTRALIA IS RAISING THE BAR ON ENERGY EFFICIENCY

Energy efficiency measures reduce the carbon footprint of built spaces, reduce heating, cooling, lighting and ventilation energy costs for owners, and improve the building occupant comfort level.

(1) When a glazed surface area of a façade is more than 20% of the total wall-glazing area, that façade has major glazing.
(2) Overall U-value (heat transfer coefficient) of windows and wall on a single façade (i.e. north).
(3) Floors with an in-slab heating system must achieve a Total R-value of 3.25.
(4) SHGC (Solar Heat Gain Coefficient) is the ratio of solar heat gained through the building’s window to the total irradiation on the window.

DO YOU NEED A SECTION J REPORT?

If you are planning to build a new building or a major extension, you need to have a report (such as Section J – Deemed to Satisfy Report) demonstrating compliance with the National Construction Code (NCC) Energy Efficiency provisions.
A Section J compliance report is part of the documentation required when applying for a building permit. The NCC is applicable nationwide, and all councils in all states require this report.

WHO CAN DELIVER A SECTION J REPORT?

Any person with any qualification that can satisfy the building surveyor’s considerations on the energy efficiency section, can produce a Section J report. However, highly qualified mechanical engineers with an in-depth understanding of building services and building materials, who has past experience with the NCC regulations, are the people who can best identify energy cost-saving opportunities and reduce construction costs while satisfying energy compliance requirements.

PROCESS AND DURATION TO GET YOUR SECTION J DTS REPORT

If we get all the required information from the client, we will be able to finish the DTS report in a single business day. The following shows the typical process.

HOW EASY IS IT TO UNDERSTAND A SECTION J – DTS REPORT?

At Energy Compliance, we want to be better than our competitors and that is why we put the time to illustrate the added insulation to all sections of the building. This way, the building construction and planning team can make sure that there is no miscommunication between parties by use of energy efficiency jargons.

We specify only the required minimum amount of insulation by the National Construction Code. Our first target is to assist the building owner to minimize construction costs, but the building owner can install as much as they want. Sometimes, this means adding more insulation to some walls to offset the overall wall-glazing thermal performance with less expensive windows. This is the level of service you can expect from the team at Energy Compliance.

Wall, roof and floor cross-sections are illustrated to make sure that what is specified in the report is installed by the builder. Here’s an example of such illustrations from our past experience:

What are the limitations of DTS Energy Compliance?

Section J is a low cost and fast compliance avenue to National Construction Code. At Energy Compliance we always recommend the DTS solution first as it is low cost. However, as it is prescriptive, it is also not flexible, which may pose a challenge to energy compliance. In some cases, achieving compliance to DTS might significantly increase construction costs (i.e. added insulation to the existing slab), or it may be highly undesirable to adopt due to aesthetic limitations. But don’t worry, there are other avenues to help reach a favourable solution, such as utilising the JV3 Performance Solution method.

Though Section J DTS reports providing a fast, simple and straight forward NCC energy efficiency compliance method, they have some potentially significant drawbacks:

1. Deemed to Satisfy requirements are very strict and must be followed with no exception. For instance, if for aesthetics reasons, the client wants to have an exposed concrete wall both inside and outside the building, the Deemed to Satisfy requirements would still require insulating every inch of that wall.
2. Fully glazed walls typically don’t pass the NCC DTS glazing requirements, or they’ll only pass with triple glazed windows which are cost-prohibitive.
3. The DTS methodology only looks at specific building fabric components as individual items and doesn’t consider the holistic performance of the entire building.
4. On the grounds of ESD, some councils may ask you to go beyond DTS (e.g. 10% better than the DTS provisions). Therefore, DTS pathway of energy compliance may not be achievable using typical glazing or insulation. In these types of situations, alternative methods of energy compliance are preferred over DTS.
5. There are no elemental provisions for Class 2 and Class 4 part of the building, therefore, the only pathway of energy compliance for Class 2 and Class 4 buildings is NatHERS star rating.
6. Using BESS tool, you can use DTS elemental pathway for energy efficiency of residential dwellings; Only NatHERS star ratings allocate certain scores for residential dwellings.

What are alternatives to DTS?

Luckily, the NCC offers an alternative Energy Compliance method that considers holistic building performance! This, importantly allows us to consider the interaction between all the different parts of the building fabric, and to improve some parts by assigning alternative, lower-cost DTS thermal performance requirements to the rest of the building.

This alternative type of Energy Compliance method is called a “Performance Solution” and is discussed in the NCC. Verification methods are performance solutions detailed by the NCC. Among these verification methods, JV3 modelling, JV2 Green Star and NABERS are the most promising methods of energy compliance for commercial buildings. JV3 is a Verification Method, which allows demonstrating compliance with the mandatory Performance Requirement JP1 in NCC Volume 1. It can be used instead of the DTS Provisions of Parts J1 to J7.

The JV3 method essentially provides flexibility in how to achieve Energy Compliance and reduce construction costs, whereas the prescriptive DTS Provisions may not work for certain building designs and maybe a higher cost approach.

Also, DTS pathway is not all inclusive. In some cases you don’t have any problem complying to the NCC energy efficiency provisions, however, your council may ask you to present evidence that your spaces are adequately daylit through verification method. if this is the case, then you need to undertake daylight modelling to back up your claim. Results of daylight modelling and DTS for energy efficiency may be contradicting to one another. JV3 modelling uses the same building model the daylight assessment does, therefore, you can save time and cost undertaking JV3 modelling instead of DTS pathway.