Wednesday, December 5, 2012

Residential Extensions Now Made Easier to Comply

It’s been a while since my previous newsletter. What a hectic year!!
We assess extensions on a regular basis. I frequently get asked questions about different matters around this topic. So I thought to write this brief newsletter to clarify a few things.
The dwelling with the proposed extension does not have to achieve overall 6-star efficiency. The Building Commission issued a new Practice Note 2011-55 in May this year. A new process has been introduced which has made it easier for residential extensions to comply.
The process is below for alteration / extension works where it exceeds 50% of existing volume.

  1. The existing dwelling will be energy assessed. Most likely it will be a low star rating.
  2. The new alteration / extension works by default must be 6-star energy efficient.
  3. Then an overall required energy efficiency will be determined. This will be based on volume and star rating of both existing dwelling and proposed works. The verdict may be 4-star or 5-star as a minimum. Hence making compliance easier.  Refer to below table as an example.

New Picture

You can see from the above example, the project complies with 4.9-star efficiency, exceeding the minimum energy efficiency requirement of 4.4-star. In some cases, the Building Surveyor may ask for additional things such as: water tank or solar hot water or other improvements.
For further information, feel free to contact our office, Efficient Energy Choices, on 03 9390 2934 or via email at
Kind Regards,
Karim Ghobrial

Monday, May 14, 2012

Efficient Energy Choices on TV

Just in case you missed it, I was on Channel 9 yesterday afternoon on a show called On Display TV. The show was about practical ways to reduce your carbon footprint.

My client, Marie Wallin from Planet Architecture also came on to show case the architectural aspects of her energy efficient house, which was assessed at 7-stars by Efficient Energy Choices.

Watch it here!


Karim Ghobrial

Tuesday, April 17, 2012


Most of you may be aware of the hot topic on the media yesterday about a proposal submitted to the Baillieu government   'to abandon 6-star thermal efficiency requirements for houses as part of its broader agenda for cutting government red tape'.

As of late yesterday, Ted Baillieu confirmed that he was not going to abolish the mandatory 6-star requirements.

To achieve 6-star is affordable, and the benefits far out-weigh the costs.  Reducing energy bills for heating and cooling, reducing water bills, and also increasing comfort within the home, are definitely the way to go!

For more information, click here:

Friday, March 30, 2012

Undercroft Insulation

Previously, I discussed the heat transfer losses in a dwelling.  To refresh your memory, at least 20% of heat transfer losses will be through a timber floor in a dwelling.  For a concrete slab on ground, those heat losses will be minimised. For more information, you may wish to refer to our earlier Blogs.

I want to take a quick look at the importance of insulating ceiling undercroft, in relation to first floor apartments as depicted in the photo below.


Without undercroft insulation, from my experience of rating hundreds of apartments, the average efficiency rating of apartments would be between 3 – 5 star efficiency. This may be satisfactory to the previous BCA 2010 regulations, but not compliant to the current BCA 2011.

Previous BCA 2010 applies to projects that were designed prior to 1 May 2011.  However, for projects designed post 1 May 2011, the minimum energy efficiency requirement for the current BCA 2011, is 5-star efficiency per each apartment.  The simplest way to ensure compliance to the current BCA 2011 is to insulate the undercroft by minimum R1.0. This can be in the form of insulation batts, Foilboard, foil or 20mm polystyrene products. These products must not compromise the fire integrity of the building.

The Table below summarises the info quick reference.

BCA Regulations
Undercroft Recommendations

Previous BCA 2010
Min 3-star per each apartment
Combined apartment average is 5-star
Can be achieved without undercroft insulation

Current BCA 2011
Min 5-star per each apartment
Combined apartment average is 6-star
Min R1.0 insulation for undercroft insulation