Changes to Energy efficiency Requirements for Alterations and Additions

As promised in our last update we are filling out some of the detail for Alterations and Addition requirements now that the official protocol has been released by the Building Commission. The protocol and documentation to be used with the protocol is available here: Building Commission Bulletin – Alterations and Additions


There will be a number of options for  compliance when the 5 star exemption lapses in May 2015.

The first will be to comply with the energy efficiency requirements of the current NCC as do new houses.

The second will be to obtain energy efficiency certification using the protocols as endorsed by the Building Commission of WA.

Why the need for the protocol?

When a HERS home energy rating system program is used the whole house must be assessed. When glazing calculators developed by the ABCB are used the whole floor must be assessed. If only part of the floor or house is being renovated this will result in an unfair burden being placed on the existing part of the house which may result in renovations and extensions being unable to comply with the energy efficiency regulations.

To counter this, the protocol has been introduced. This protocol operates under a number of key principles. Firstly that all parts of the house, after renovation, will achieve the same or better level of energy efficiency. Secondly by upgrading existing parts of the house, that would otherwise be untouched during the renovation project, this will result in better energy efficiency overall and should be encouraged. Thirdly the NCC is still the authority and unless an item is specifically mentioned in the protocol the NCC is to be used.

What does this mean?

In general terms:

  • The new portions of a building needs to meet the latest energy efficiency requirements.
  • Existing parts not being changed but are part of the affected area, need to either remain as is or to the BCA that was applicable when building license was applied for(whichever is higher).
  •  If parts of the existing are improved(EG add ceiling insulation to parts where there is currently none)  then a concession can be used for the new section of the building.
  • Alterations and additions that affect more than 80% of the residence have to comply with the full energy efficiency regulations as if they are a new house.
  • Alterations and additions that affect less than 10% of the residence may be unaffected by the energy efficiency regulations, under certain circumstances.
  • There is both a HERS(Star Rating) and an Elemental Provisions(Glazing calculator etc) option as there is with new houses.  Which will be best will become clear as we do more testing, however we expect that what works for new houses will  also hold true with the additions and renovations.  


How to comply

Some important changes are needed in the documentation of projects that will lodged for a building license after May 1st 2015 and will be affected by the new regulations.

Most importantly the whole house, even the portions that will be unaffected by the additions and alterations, needs to be documented. Documentation will need to include construction types, insulation currently installed, window and door sizes of both remaining windows and new and year that the building license was applied for. If there are a number of additions or extensions in the past the date of building license application and the parts that were affected by that application will need to be identified for each section.

With the above information we will then be able to assess which method will be more suitable for your project.

The protocol also details how to deal with smaller renovations etc. such as new roof cover, roof colour changes and external cladding changes.

It is expected that the protocol allows the flexibility to ensure a good outcome for renovations and extensions that does not overly burden the industry but at the same time will result in greater energy efficiency for new building.

However to make sure the protocol  is used effectively and the best result is achieved for your project it is very important to make sure that the person doing your assessments on additions and alterations has a good understanding of the BCA energy efficiency regulations as a whole as well as the new protocols and tools released.

Over the coming months leading into the application of the new regulations we will be releasing more data on how to comply and which method works best for which projects.

If you have any specific questions, items you need clarifying or would like to contribute a set of plans for the case studies please let us know.

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