Energy Efficiency


table and paradigm

Doesn’t everyone want a low maintenance house that is energy efficient? Comfortable to live in and not feeling confined in an esky. What everyone should want is Thermal Comfort.

This is why architects come up with unusual stepped plans for more light and airflow. Higher walls for light and airflow. More glass for more natural light, more larger openings for more light and airflow, higher ceilings , these all bring the outside (view) in and extend the inside spaces outside. The house shown in this article has shown to be the best most energy efficient house designed by Architects Black  & Wilson to date and it was expected to rate about 9 stars in energy efficiency.

breeze solarium

Extensive sun studies using latest computer real life 3D modelling and perfectly orientating the building and overhangs to totally control the sun and its penetrating heat.

Other physical elements were added to provide efficiency.

To minimize energy usage, the design incorporated the following

-a boomerang shape facing north

-angular verandas shaped to articulate sun control

-angular sloped eaves shaped to articulate sun control

-double glazing to high heat load east and west windows

-low “e” glass throughout

-extensive roof wall and ceiling insulation

-in floor heating

-in wall heating to dwarf north walls

-electrically operated roof vent systems

-electrically operated louvres

-ceiling fans

-thermal mass sinks

-battery ready solar power

-reverse block veneer.

Reverse Block Veneer

reverse block veneer

Reverse Block veneer is being used internally rather than externally for its thermal mass, and aesthetics. Block absorbs heat and contributes to the cooling of the house. This is evidenced in caves; the air temperature drops considerably on entering a cave. In addition, honed and polished blocks are used for their looks. Ironically, they give the warmth often expected in colder climate houses. The thermal mass of the blockwork will also absorb the heat from the fireplace and re- radiate it back into the room at night.

Energy Boxes Ticked

fire place

It was believed all the energy boxes were ticked. So, it was a surprise to learn the model for this house received 5.5 stars as National Building Regulations are designed assuming all houses are air conditioned ‘Esky’ homes with small windows.

So, what happened for this result?

The amount of glazing reduced the star rating. Remember Low “E” glass and double glazing was used, the energy rating system to rate this house deemed the glass as either ‘to keep heat out’ or ‘to keep the heat in.’

Shading was used


This design used shade control to keep the sun off the glass in summer. The problem is it’s hard to find glass designed to let heat in and trap it, which is what is needed in winter.

Bedrooms and Living rated well

energy rating

As it turns out the Bedrooms rated 9 stars and the living rooms 7 stars. The Breeze solarium (the wedged shaped room in the centre of the house, acting as a funnel for prevailing breezes in summer and a sunroom in winter), arguably the best climactic design feature only rated 2.5 stars! Under the Standard DTS (Deemed to Satisfy) Climate Model the internal breeze solarium would actually rate higher if it was ‘Permanently open on both sides.’

This would be great when temperatures reach 40 degrees, but it also snows here

Empirical Data  Collected

emprical data collected

The client chose not to waste anymore funds on software with only standard criteria for energy rating. The client chose instead to log their temperatures over 4 consecutive days. The graph shows a reduction in temperature of 10 degrees from internal temperature to exterior temperature of 36 degrees.

cost comparison

All these design improvements have a real dollar cost, so is it worth it compared to Spec Homes?

When comparing ask the questions:

Why not just air condition the building, there are two costs of installation and running costs, and in our climate Fresh Air is free and healthier. Feeling connected to nature is relaxing after being cooped up in work in air conditioning all day.

Remember how different it feels when experiencing holidays at the beach. Bring that feeling home with every time you walk through the front door.


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