What is Section J
A Section J report outlines the energy efficiency requirements for Class 3, 5, 7, 8 and 9 commercial buildings which is defined by Section J of Volume 1 of the National Construction Code (NCC) of Australia. The Building Code of Australia outlines that Section J reports should be prepared using Deemed-to-Satisfy (DTS) provisions and verification using a reference building (JV3) verification methodology.
Due to Australia's unique and varied climates different locations have different heating and cooling requirements. As a result the energy efficiency DtS provisions vary due to location. The NCC have classified these locations into 8 zones.
Section J Reports are designed to:
reduce greenhouse gas emissions
lessen energy consumption for heating, cooking, lighting, ventilation and other building services
Improve the systems which directly consume energy
Exert greater control over the flow of heat in and out of building fabric
Section J Reports are required:
By all non-residential (commercial) buildings which fall between classes 2-9
In all states across Australia
The majority of councils and certifiers will require a Section J assessment during the Development Application
Energy efficiency is the main standard of Section J Reports and can be applied to insulation, building fabric, external glazing, air conditioning, ventilation, lighting, power, hot water and spa plant pools. Section J Reports outline the solutions that are required for the development to meet the requirements outlined in Section J of the NCC.
Section J compliance is assessed on nine categories with the building measured to assess the thermal performance for new dwellings or the rate in which it assumed existing thermal performance for alterations and additions to existing properties.
Each building is assessed using a glazing calculator to assess thermal performance of all glazed elements with glazing and frame type considered as well as window orientation. A lighting calculator is also used to assess the required and maximum energy usage of a given room with the aim being to reduce energy consumption as well as complying with state and national energy efficiency goals.
Any area which does not meet the requirement will need recommendations in order to meet the requirements of the DtS provisions.
The Energy Efficiency requirements are broken down as below:
Part J1 - The building's fabric performance
Part J2 - External glazing and shading
Part J3 - Sealing of the building
Part J5 - Heating, ventilation and air-conditioning
Part J6 - Performance of artificial lighting
Part J7 - Heated water supply system for heating and pumping of pools and spas
Part J8 - facilities used to monitor energy usage
U and R Values
U and R values refer to the thermal performance of specific products and materials and how they assist in maintaining thermal control within a building or structure. These values are an integral part of Section J Reports with specific values required to be entered.
The U Value of a product refer to heat loss through building elements and is calculated at the rate of heat loss per meter square of material. The lower the U value the better performing the product.
R value represents the thermal resistance of building elements, and unlike U Values, the higher the R value the better with a higher value demonstrating better insulation.
Solar Heat Gain Coefficient (SHGC)
SHGC refers to the amount of radiant solar heat which is absorbed or blocked by glazing. The number for SHGC refers to the fraction, or percentage of heat released inwards through glazing. Properties which require heating during winter months would therefore require higher performing SHGC glazing whereas properties requiring cooling should target lower performing glazing.