Energy Performance Solution

Since 1996, the Building Code of Australia has been performance-based, allowing for Energy Performance Solutions. This enabled the compliance process with the requirements of the code to be carried out cost-effectively and with more flexibility. When certain Performance Requirements regarding the energy efficiency provisions of the code are challenging to achieve or not applicable in certain parts of the project, we offer our expertise in Energy Performance Solution services to our clients.

Energy Performance Solution

What is a Performance Solution?

The National Construction Code (NCC) of Australia defines a Performance Solution as a method of achieving compliance with the Performance Requirements of the code, other than by following Deemed to Satisfy (DtS) provisions. An Energy Performance Solution aims to meet the Performance Requirements of the Energy Efficiency section of the code not by adhering to the DtS provisions, but through innovation, compensation and analysis.

Here’s an example to put things simply. Suppose you own a restaurant and have developed a food recipe. If your chefs follow this recipe, customers will find the dish tasty, and ultimately, the restaurant makes a lot of money. In this example, the recipe represents the “Deemed to Satisfy (DtS) provisions”. One day, one of your top chefs decides not to follow part of the recipe and instead, proposes a new roasting method. This new recipe is similar to a “Performance Solution.” The restaurant owner oversees the customers’ satisfaction with the new recipe. If the new recipe draws an equal or greater number of customers, the owner will approve replacing the old recipe with the new one. Ultimately, customer satisfaction is the “Performance Requirement” and the restaurant owner must maintain it, whether by following the old recipe (i.e., DtS provisions) or the new one (i.e., Performance Solution).

When is a Performance Solution required?

Sometimes, meeting the energy efficiency Performance Requirements of the code is not feasible. In such cases, Performance Solutions, also known as Alternative Solutions or Performance-based Solutions, help you achieve cost-effective compliance. For:

When is an Energy Performance Solution required?

Building Fabric

  • Glazing: Often the compliant glazing from DtS results in a high-performance glazing system like triple-glazed thermal break windows. In such cases, an Energy Performance Solution is preferable to meet the Performance Requirements.
  • Insulation: Sometimes it is not feasible to install insulation in parts of the building; therefore, you need to undertake an Energy Performance Solution to keep existing slabs or heritage walls from the new insulation installation works.
  • Roof Colour: In case the building code doesn’t allow the installation of dark roofs, Performance Solutions can justify its use.
  • Structural: Where some external walls are load-bearing and installing insulation defies the integrity of the structure, an Energy Performance Solution helps by having more than the required insulation elsewhere as compensation.
  • Aesthetics: Rammed earth or similar materials pose a sense of belonging to nature and can attach an identity to some building designs. In these cases, builders prefer not to install insulation on either side of the wall; therefore, an Energy Performance Solution is required to claim that the building achieves energy compliance through other means.

Building Services

  • Energy Efficiency: In case a high-efficiency air-conditioning or ventilation system is expensive to install, you can compensate for the lower-efficiency systems by installing more insulation, high-performance windows, or renewables.
  • Lighting Intensity: DtS Provisions for artificial lighting set the allowable illumination intensity in a room. If you need to have more illuminance, for example, in a luxurious restaurant, then you would need to undertake an Energy Performance Solution.
  • Pipe Insulation: Fabric refrigerant pipe insulations often have thicknesses lesser than the required insulation under the building code. In such cases, you can undertake a Performance Solution to compensate for the low-performing pipe insulation by having high-efficiency unitary air-conditioning systems.
  • Renewable Energy: The Building Code of Australia doesn’t have requirements for most renewable systems. If you are planning to install such systems, Energy Performance Solutions help you achieve a cost-effective solution and low-cost construction as the renewables can compensate for the lack of low-performance building fabric and services.
  • Innovation: Many technological or structural innovations have a positive effect on the energy efficiency of a project. These innovations are not requirements in the code and, in many cases, are not addressed in it. If you are planning, for energy-saving reasons, to install such systems, you may be able to have some compensation for building fabric and other services with lower performance than required. Some of these innovations are Trombe walls, phase-change materials (PCMs), occupancy-based ventilation, demand-controlled ventilation, heat recovery systems, solar-assisted heating systems, and more.

What are the benefits of Performance Solutions?

There are three ways to achieve compliance with the energy efficiency Performance Requirements of the BCA:

  • Deemed to Satisfy Provisions: The design team should strictly follow these provisions to achieve compliance with the code. These DtS provisions set the amount of insulation, performance of glazing, efficiency of equipment, and more. We regard these requirements as a simple pass-or-fail test.
  • Performance Solution: If, for any reason, a building does not achieve compliance using DtS provisions, the NCC requires a Performance Solution as an alternative approach to meet the Performance Requirements. These requirements often involve the
  • A mixture of DtS and Performance Solution
Energy Performance Solution for residential buildings

There are several benefits when undertaking an Energy Performance Solution instead of Deemed to Satisfy provisions, including:

  • Cost-effectiveness: Energy Performance-based solutions often result in achieving energy compliance with lower construction costs.
  • Innovative Design: Performance Solutions provide a basis for implementing new design features and innovative ideas, recognizing reductions in energy use and the possibility of compensation.
  • Flexibility: Unlike the DtS pathway’s provisions, through Energy Performance Solutions, you can pursue any path available to compliance according to the project’s needs.
  • Sustainability: The NCC has very few mandates on renewables and sustainable energy solutions. Therefore, the evaluation of the impact of renewables on energy savings is possible only Energy Performance Solutions.

The following section shows several Energy Performance Solution examples undertaken by the Energy Compliance Consultants team.

Energy Performance Solution for copper piping insulation

Energy Performance Solution for Refrigerant Copper Piping Insulation

Energy Compliance Consultants has been engaged to develop an Energy Performance Solution for the mixed-use development at Epping, NSW.

This Energy Performance Solution demonstrated that the use of high-efficiency VRV units for air-conditioning compensates for the energy loss due to the lack of proper refrigerant piping insulation. Since the piping insulation used for space heating and cooling falls below the prescribed value under DtS provisions of Part J6D9, a performance-based solution is required. This represents as an evidence that the proposed building complies with the Performance Requirements of the Section J.

Our Energy Performance Solution outcome showed that, due to lower refrigerant piping insulation, the proposed building experiences a 1.4% increase in heating and a 2.6% increase in the cooling load of the unitary units. However, the proposed building, with the use of high-efficiency unitary HVAC equipment, not only compensates for this increase but exceeds the requirements of Section J, reducing peak energy demand by 5.1%, and annual energy consumption and greenhouse gas emissions by 6.8%.

Energy Performance Solution for Wall Insulation

Energy Performance Solution for wall insulation

Energy Compliance Consultants has been engaged to undertake a Performance Solution to demonstrate the energy efficiency compliance of the proposed showroom at Invermay, TAS. We intended to show that by installing an adequate Solar PV system, the external walls of the development could remain uninsulated. Our Energy Performance Solution involved using the JV3 Verification Method to demonstrate energy compliance for the development. Ultimately, our Performance Solution report demonstrated that by installing a 33KW Solar PV system, the external walls of the showroom could remain uninsulated. Our Performance Solution using the JV3 Verification Method also resulted in a 1% reduction in GHG emissions compared to the NCC Reference Building model.

Energy Performance Solution for Radiant Heating Panels

We were engaged to undertake a Performance Solution for the proposed restaurant at St Helens, TAS. The developers had two demands:

  • The project manager aimed not to install any cooling equipment; and
  • They needed to supply space heating locally via radiant heating panels.

Through the Energy Performance Solution pathway, we demonstrated that space cooling is not a requirement as the thermal comfort of occupants is within the acceptable limits of NCC Section J. Additionally, by installing a 4.3 kW Solar PV system for lighting and other purposes, the proposed building was able to compensate for the lack of a proper heating system in the indoor area.

Energy Performance Solution for heating
Energy Performance Solution for not using BASIX

Energy Performance Solution instead of BASIX in NSW

National Construction Code (NCC) has no Deemed to Satisfy requirements for Class 1 dwellings in New South Wales. To obtain a building permit, dwellings must obtain the necessary BASIX points. Therefore, only DIY and NatHERS rating are the acceptable pathways for thermal performance compliance in NSW.

For this project at Callala Beach in NSW, our client wished to have almost 70% of the external walls made of rammed earth. Our proposed Energy Performance Solution required precise energy modelling of the building instead of the standard NatHERS approach. Due to aesthetic and structural reasons, our client didn’t want any insulation for the rammed earth walls. Since NatHERS is unable to account for thermal mass, we aimed to evaluate it through reference building approach. Ultimately, we increased the performance of windows, floor, and roof insulation to compensate for the low performance of external walls.

Energy Performance Solution for Glazing

Energy Performance Solution for low-cost windows

We were engaged to undertake an Energy Performance Solution for a dwelling at Keysborough, VIC. The Performance Solution intended that the NatHERS rating required the project to have glazing with an overall U-value of 2.2. We proposed the VURB Verification Method instead of NatHERS to lower the cost of glazing. VURB is a compliance pathway verified by the NCC. It requires modelling the building and evaluating its thermal demand against a reference building. VURB involves simulation capabilities and accounts for various mechanics NatHERS cannot. Also, VURB compares the building to its reference version, not a benchmark. Through precise calculation of the impact of thermal mass, solar gain, heat storage and more insulation, we delivered our promise. Using the VURB pathway, we achieved a U-value of 3.2 (a 45% increase) and eliminate the need for thermal breaks.

Energy Performance Solution for Off-Grid Dwellings

This project at King Island in NSW was an off-grid dwelling (i.e., not connected to a gas or electricity grid). For this purpose, we prepared a Performance-based design brief that, instead of using BASIX, aimed to:

  • Thermal Comfort: The building needed to maintain the thermal comfort of the occupants and ensure passive resilience to ambient weather extremes. To achieve this, we aimed to achieve a 5-star NatHERS rating instead of a 7-star rating.
  • Grid-Independence: There were no connection to the grid network and therefore, the building did not produce any greenhouse gas emissions. Thus, we argued that it is not subject to the Performance Requirements of NCC Vol 2.0, Part 2.6.2. However, the building still needed a source of energy to meet its energy demand for space heating and cooling. Therefore, part of our Energy Performance Solution required the utilization of solar PV and battery system to maintain grid independence.
Energy Performance Solution for off-grid

FAQ

There are two ways for a building to meet the Performance Requirements of the National Construction Code (NCC):

  1. Deemed to Satisfy (DtS): This compliance pathway involves strictly following the provisions of the Building Code of Australia (BCA). This rigid method doesn’t allow for any compensation or dispensation.
  2. Performance Solution: This method allows for compensation or dispensation for some provisions in the code while still meeting the Performance Requirements. Sometimes, a Performance Solution is used as evidence to show that a building meets a Performance Requirement.

A combination of these two methods can also be used to determine if a building complies with the requirements of the code.

An Energy Performance Solution is a type of Performance Solution that addresses the energy efficiency requirements of the code. It focuses on alternative ways to meet the Performance Requirements for building fabric and services. For example, an Energy Performance Solution could propose that an all-electric off-grid house in Victoria be exempt from the required 7-star energy rating by achieving a 5-star rating and installing a solar PV and battery system.

Yes, NCC is a performance-based building code. NCC Volume 1.0, Part A2 outlines the compliance pathways within the NCC. In Clause A2G2, the NCC specifies the credibility of a Performance Solution as a valid compliance pathway.

There are several accredited performance solution pathways in the NCC, referred to as Verification Methods:

There are five instances where an Energy Performance Solution helps achieve compliance with the Performance Requirements:

  • Infeasibility of Code Requirements: When following certain requirements in the code is not possible.
  • DtS Provisions Inapplicability: When applying Deemed to Satisfy (DtS) provisions is not feasible.
  • Dispensation Needs: When some requirements are not applicable to a building, and a dispensation is required.
  • Design Evidence: When a Performance Solution is needed as evidence that a design or solution, although not evident, meets the Performance Requirements.
  • Innovation and New Methods: When the building utilizes innovative and new construction methods not outlined or recognized in the code but helps in achieving compliance.

The process of conducting a Performance Solution involves four steps:

  1. Performance-Based Design Brief: The assessor prepares a design brief that outlines the relevant stakeholders, the rationale for the Performance Solution, the analysis method, and the metrics for compliance evaluation. This design brief must be signed by all relevant stakeholders.
  2. Analysis: Based on the method outlined in the design brief, the assessor conducts the analysis (often through computer modeling) and implements the Performance Solution.
  3. Results: After multiple trials, the assessor gathers evidence and extracts the analysis outcome to demonstrate that the compliance, as discussed in the design brief, is fulfilled.
  4. Reporting: The final stage involves compiling a final report, including all documentation and evidence required to demonstrate that the Performance Solution meets the Performance Requirements of the code.

A Performance-Based Design Brief (PBDB) is a crucial document that outlines the fundamental information about a Performance Solution and must be prepared as a justification before implementing this alternative method. This design brief is prepared by a designer or assessor and includes the following sections:

  • Scope of the Proposed Solution: Defines the reason and the objectives of the Performance Solution.
  • List of Relevant Stakeholders: Identifies all key stakeholders, their roles and means of contact.
  • Building Information: Provides information about the site and the building.
  • Applicable Performance Requirements: Outlines the Performance Requirements that is applicable to the building.
  • Agreed Acceptance Criteria: Outlines the criteria agreed upon by stakeholders to evaluate the succession of the Performance Solution.
  • Method of Analysis: Describes the methodology used to assess the Solution.
  • Required Documentation: Lists all the required documentation for the solution.
  • Format of the Final Report: Details the format and content of the final report.
  • Limitations and Considerations: Identifies any limitations or special considerations relevant to the solution.

To achieve energy compliance with the Performance Requirements using the Deemed to Satisfy (DtS) method, the energy efficiency provisions must be strictly followed. This method does not allow for any compensation, dispensation, or flexibility. However, using an Energy Performance Solution, a building could be exempt from some requirements by implementing other justifiable, cost-effective solutions.

Here are a few examples:

  • Low cost windows: By using a Performance Solution, the installation of low-cost windows can be justified by adding more insulation to the ceilings or floors.
  • Off-grid houses: An off-grid house, which does not burden the electricity grid, can be exempt from the required 7-star energy rating by installing a solar PV system and batteries.
  • Pipe insulation compensation: A high-efficiency VRV (Variable Refrigerant Volume) system can compensate for the required copper pipe insulation thickness outlined in the building code.

To ensure that buildings receive adequate natural light, the National Construction Code (NCC) specifies a Performance Requirement under Part F6P1. According to this clause, a room must achieve a minimum Average Daylight Factor (ADF) of 2% through sufficient openings.

To meet this requirement using the Deemed to Satisfy (DtS) approach, windows providing natural light must have a light-transmitting area that is at least 10% of the floor area they serve. Additionally, there should be no obstructions within 1 meter in front of the window.

If any of these conditions are not met but the project team is confident that they can still achieve the required ADF of 2%, they may undertake daylight modelling as a Performance Solution to fulfill the Performance Requirement.

In some cases, yes. An exemption from the NatHERS rating can be obtained from the authorities on three grounds:

  • Unconventional Design: When a building design is atypical and differs significantly from the benchmarks of NatHERS, the owner can request an exemption from the NatHERS rating. Instead, they can undertake thermal energy modelling as an Energy Performance Solution. For example, buildings such as PODs with a high glazing ratio may fall into this category.
  • Off-Grid houses: If a project is far from the electrical grid and will not be connected to it, it will not produce greenhouse gas emissions or burden the electricity grid. Therefore, it does not need to achieve a NatHERS 7-star rating. Instead, as evidence that the building is well-insulated to maintain occupant comfort, a 5-star rating can be considered sufficient.
  • Verification Methods: If it is not possible or feasible to install Deemed to Satisfy insulation, or if achieving a NatHERS rating results in expensive windows, the project team can use NCC-approved verification methods to conduct an Energy Performance Solution.