Some of our JV3 Projects
What is a BCA Section J JV3 ?
Under the broader spectrum of the NCC, volume 1 of the BCA contains Section J which documents the list of provisions that a building design must comply with in order to satisfy the energy efficiency requirements of the building code of Australia. Section J was introduced as a result of energy emitters not being sufficiently encouraged to conserve energy and use sustainable means of usage. The Deemed-to-Satisfy (‘DTS’) provisions of the section J lists the minimum requirements of a building to follow in order to demonstrate compliance with the section J of the BCA. However, if a certain development does not meet these standards, or if a developer wishes to change some aspects about the building’s design which would make the building non compliant with the DTS requirements, an alternative assessment pathway is available which allows the building to have DTS non-compliant elements and still be compliant with the section J as a whole. The methodology and assessment guidelines for conducting an alternative solution to section J of the BCA is documented under the JV3 part of the section J and therefore it is referred to as a JV3 alternative solution assessment.
The JV3 verification method can also be used as a performance solution to demonstrate compliance with the Performance Requirement JP1 which states; A buildings, including its services, must have, to the degree necessary, features that facilitate the efficient use of energy appropriate to:
- the function and use of the building and services
- the internal environment
- the geographic location of the building
- the effects of nearby permanent features such as topography, structures and buildings; and
- solar radiation being- (i) utilised for heating; and (ii) controlled to minimise energy for cooling
- the sealing of the building envelope against air leakage
- the utilisation of air movement to assist heating and cooling
- the energy source of the services
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JV3 Alternative Solution Compared to DTS
In a DTS BCA Section J assessment, all the building elements are being checked against the relevant part of the Deemed to Satisfy requirements of the Section J and these requirements are documented and reported in a BCA Section J DTS Compliance Report. These are minimum requirements necessary for compliance and are in the form of declarative statements and cannot be changed or deviated from.
A JV3 alternative solution method is approaching the matter of compliance from a different angle. The JV3 method is the guidelines and methodology documented in the JV3 part of the section J. These guidelines show how a building energy computer model must be generated in order to demonstrate that an alternative solution to the DTS provisions is still compliant with the requirements of the Section J while one or more elements in the design might not comply with the relevant parts of the Section J requirements. This is a critical necessity due to the fact that, many times, the design restrictions, product availability and cost might not allow for the direct wording of the DTS to be complied with.
The ultimate favourable outcome of the JV3 method is to demonstrate that an alternative building solution meets relevant performance requirements of the BCA section J even if one or more of its elements do not comply with the prescribed requirements of the deemed to satisfy provisions. The JV3 Method can allow for innovation and better use of a building’s fabric and services in order to make the building more energy efficient.
To achieve this level of compliance for the alternative solution, a computer-simulated thermal modelling process is undertaken by following the strict guidelines of the JV3 section of the NCC volume 1. While during a DTS assessment, each element of the building must be compliant with the minimum performance requirements by its own, a JV3 computer model recognises and takes into account the interaction between various elements and allows for meaningful and educated trade offs. It may initially seem like it is easier to retain compliance with the DTS approach however, in almost every occasion, a DTS compliant solution will ultimately end up costing more during construction and procurement and the building itself will not perform as efficiently to save and preserve energy.
JV3 Cost Savings
Due to the inflexible and directive nature of the DTS provisions, there is no room for any flexibility and optimisation when these requirements are in direct conflict with the intended use and functionality of the building or when they are practically or commercially impossible to comply with. To address these inherent shortcomings of the DTS approach, Section J provides documentation and methodology for an alternative solution under JV3 section. The use of computer modelling allows for a high degree of optimisation and customization and highly optimised building and component performances.
A JV3 assessment is capable of achieving a building solution without essentially complying to all of the DTS requirements. While it may seem like the initial cost of conducting a JV3 assessment is financially burdensome, in fact, formulating a JV3 assessment allows a noticeably larger saving during the construction phase of the building. It also delivers a more uniform and practical building solution particularly for glazing requirements of the BCA Section J which, based on our experience, is the primary area of concern for developers for compliance with the DTS requirements.
JV3 Assessment process
The basic approach for conducting a JV3 alternative solution assessment is to use computer simulation to demonstrate that the annual energy consumption of the proposed alternative solution is equivalent or better than the annual energy consumption of a reference building which complies with all the DTS provisions of Section J of the BCA.
The performance of the alternative solution must be better than the performance of the reference building when simulated with the DTS compliant services, as well as with the alternative solution proposed services. This essentially means that we are required to have several software modelling and simulation runs in a JV3 assessment, explained below.
Software run 1: In this step, the annual energy consumption of a reference building, which is a DTS compliant building based on the JV3 criteria, is calculated.
Software run 2: In this step, the annual energy consumption of the alternative design solution building is calculated by computer modelling which can be either by the building’s own criteria or the ones detailed under Specifications of the JV3 section.
Software run 3: This is the same as run 2 but the services must be modelled as the ones in the run 1 which are DTS compliant services.
The annual energy consumption results of run 1 should be equal or less than both run 2 and 3 in order to demonstrate compliance of a building under JV3 provisions. This essentially means that the thermal performance of the building’s envelope could not be “traded-off” for more energy efficient building services. However, JV3 permits the trade-off to go the other way, that is, we can have better performing building envelopes and lower performing services compared to the DTS and our alternative solution still complies with the BCA Section J requirements. The rationale behind this approach is that building services may change over the lifetime of a building, or a lack of maintenance may cause the performance of the services to diminish over time. But once the passive energy efficiency requirements for the building envelope elements are in place, they generally maintain their original performance level for the lifetime of a building.
What Should a JV3 Report Include?
A JV3 assessment requires a 3D model of the building to be created using specialised building energy modelling software. The model is then simulated in different scenarios with the DTS compliant building elements and with the proposed alternative solution. A BCA Section J JV3 compliance report must document and elaborate on these results and demonstrate the overall building solution which would be compliant with the Section J provisions including the renewable energy sources if necessary.
The report must also contain the results of thermal comfort calculations of the alternative solution energy model as required in the Section J. This is another criteria which has been introduced to the JV3 methodology from 2019 version of the NCC which requires the internal comfort conditions of the building to be maintained within a certain acceptable limit regardless of the compliance of the building for its energy consumption.