Alternatives to decreasing window size

Hi all,

We’ve been asked to considerably decrease the size of many of our windows to meet a 7 Star Energy rating. We are very reluctant to do this, as we don’t want to turn our house into a dark box.

Is there an alternative to reducing window size? Such as double glazing, install awnings etc?

We have asked Structerre to come back with other suggestions to get our house to 7 star but I’m not optimistic, as I haven’t had one good experience with Structerre so far.

Thanks,

Kelsey

Add internal wall insulation maybe?

good luck in using software other than Nathers
LOL, in which you can't even model airflow
the problem becomes the results will have to be certified and it's not worth the effort and costs if you are building in WA
Here Try opening windows for cooling and Modelling Airflow displacement and the static nathers energy calculations fly out the door and becomes useless.
Cheers
Chris

Hi kelsey
See if upgrading glass to something like comfort plus (low E glass) helps, then go to double glazed.
You may also be able to offset by going with thicker ceiling insulation.
In our build we have a fully glazed living, dining kitchen. We had to use comfort plus and thicker ceiling insulation in addition to full cavity insulation.
Who are you building with? I've used Structere in the past but they wouldn't be my first choice. I know they have many of the big builders using them but if you can choose, I'd opt for another company.

Edit: our house is only rated at 6 stars I believe not 7.

Here is a few small things that can make a difference.

How far along in the planning process are you Kelsey?

The most important thing to do when planning a home is to orientate or correctly. That is, locate living areas (& a large proportion of glazing) to the north, minimise western (& to some degree, eastern) glazing.

Importantly, this will result in a home that is much more comfortable. Lighter, warmer in winter, cooler in summer. It will lower your energy bills, & yes, IT WILL INCREASE YOUR STAR RATING.

So firstly, I'd ask, is your home orientated correctly. North facing living areas will be light throughout the day. Alternatively, south facing living areas will be dark the majority of the time. East facing living areas will only be light in the morning, but will have to contend with morning summer heat. While western living areas will only be light in the afternoon, & will have to contend with the hot afternoon summer heat - even worse is west facing bedrooms, yuck!

So it's certainly not a good idea to have large windows facing all directions!

It's a much better idea to have a good amount of northern windows (though not too much), quite a bit less southern & eastern glazing, & very little or no western glazing.

Building a home to these principles is called "passive solar design".

https://www.yourhome.gov.au/passive-design/orientation

Ignoring orientation will not only lower your star rating, it will reduce the comfort of your home, & increase bills. So if your home isn't orientated correctly, I'd certainly be making major changes.

This may be as easy as relocating windows, or flipping the plan, & moving some windows.

The next most important way to increase your star rating - increasing comfort & lowering bills - is to upgrade insulation. Australia's minimum standards are poor by developed countries standards, & minimum standards are not enough. So if you haven't already done this, I'd be upgrading insulation levels.

The brilliant Your Home website - the government's guide to sustainable, energy efficient home design - which I linked above says for most climates - MINIMUM insulation levels should be R4.1 for the roof/ceiling, R2.8 for the walls. I standard 90mm timber stud wall will fit an R2.5 batt. I'd certainly be putting this in the walls at the time of the build, as it's extremely difficult to do afterwards.

If you're building with double brick, some insulation can be placed between the leaves of brick. Though you certainly won't be able to reach R2.5. Personally, I hate double brick, it's a thermally inefficient building method. I'd choose a timber frame, with lightweight cladding, brick veneer, or even reverse brick veneer if you want to get adventurous. Though I guess you might be too far along to make these changes?

Alternatives to reducing Windows to increase energy efficiency?

Root and ceiling insulation. Upgrade it as high as possible. Will require ceiling joist upgrades and other members.

Building with stud work internally? Insulate. Brick? Drywall over brick but very small increase.

Double glaze Windows. Add a thermal break. Orientation specific glazing I.e. SHGC and U values.

Specify flooring to assessor. I think tiles are best but can't recall.

Specify drapes and pelmets.

Remove all down lights and replace with surface mount light.

Move Windows to other walls where possible.

Raise sills.

Light colour external colours.

Build with a single skin external stud wall and cladding.

Add ceiling fans

I'm sure it already is but have draft stoppers to exhaust fans.

Eave and roof vents.

Slab insulation including slab edge.

If two storey avoid balconies over habitable room.

Insulated garage door.

That's all I can think of right now

Alternatives to reducing Windows to increase energy efficiency?

Root and ceiling insulation. Upgrade it as high as possible. Will require ceiling joist upgrades and other members.

Building with stud work internally? Insulate. Brick? Drywall over brick but very small increase.

Double glaze Windows. Add a thermal break. Orientation specific glazing I.e. SHGC and U values.

Specify flooring to assessor. I think tiles are best but can't recall.

Specify drapes and pelmets.

Remove all down lights and replace with surface mount light.

Move Windows to other walls where possible.

Raise sills.

Light colour external colours.

Build with a single skin external stud wall and cladding.

Add ceiling fans

I'm sure it already is but have draft stoppers to exhaust fans.

Eave and roof vents.

Slab insulation including slab edge.

If two storey avoid balconies over habitable room.

Insulated garage door.

That's all I can think of right now