In April I had to pleasure to participate in 3 panel discussions with National Design Matters; Designing for 7 Stars.

Together with Jeremy Spencer (Positive Footprints), Darren Parker (Greenest House) and Shae Parker McCashen (Green Sheep Collective) we discussed the proposed updates to the energy efficiency standards in the National Construction Code.

The 6-star energy requirements as they stand today were introduced in 2010. So yes, the upcoming changes are long overdue. Back then, when it changed from 5 to 6 stars, there also was resistance and fear within the industry.

Many people believe it will drive the construction cost up further. And that it will be a difficult transition for the industry.

Will it be difficult?

Well, it depends. For anyone already in the energy efficient and sustainable home design space, not much will change.

But some people in the industry will struggle to get the houses up to 7 stars. Going from 5 to 6 stars was easy in comparison.

In most instances you needed to add a bit more insulation and you needed better performing windows. Meaning this was easily done on paper. Obviously, it did cost more money. But the houses could typically stay as they were, mostly unchanged.

Going from 6 to 7 stars however will have a deeper impact. Suddenly the design and orientation of the house has a much bigger influence. For instance, it will be difficult to get a house with poor solar access up to 7 stars. There is only so much insulation you can fit into a standard wall. And most designs do require double glazing anyway to get them to the 6 stars. And even with the best double glazing, some home designs will struggle to get to 7 stars.

So, what does this mean?

It means it will be difficult and sometimes impossible to take any old project home and plunk it on your site. Passive solar design principles must be adhered to. The living areas must be designed and located according to the actual site and orientation. Allowing maximum solar access into the house. While also taking shading and overheating in summer into account.

The responsibility lies on the designers and architects. We must make sure that what we design can be built. We can’t just design what we want or what the clients want. In some instances, we might have to step up and educate the clients. And sometimes what they want might not be achievable.

I imagine there might be some difficult conversations to be had.

But imagine how horrible it would be if you had work for weeks or even months to design your dream home. Only to find out later that you can’t get a building permit because your house does not comply with the minimum energy efficiency standard. That would lead to some very unhappy clients, and it would be embarrassing for the designer as well. Wouldn’t it?

If we look at the issue from another angle; you are not allowed to have a window on your boundary wall. It’s just the way it is. And similarly. You can’t have all your living areas facing south with no north facing windows. Even if all your views are to the south. And it’s the designer’s or architects’ responsibility to come up with creative ways to give the clients the design and house they want, while making sure the design complies with the energy efficiency requirements.

Could this be the end of the project homes?

And what should the volume builders do?

Well, I think they have to come up with more customised designs. Rather than only concentrating on the number of bedrooms or living areas. I think they will need a range suitable for the west facing block, one for an east facing block and so on.

Another option is that you design a house up to 7.5 and 8 stars. In which instance it will most likely still perform as a 7-star home, even if rotated on site. However, higher performing glazing might be required.

In general, I think the times of single glazing are well and truly over. In my opinion single glazing should be banned altogether. Windows are the weakest point in our homes. Even the best triple glazing window does not perform as well as an insulated wall.

In my opinion we need a minimum performance (a maximum u-value) for windows. To make sure there are no thermal bridges and air-leakages in our building envelope.

We also must rethink how and where we use glazing. You can’t have full height glazing everywhere, on all sides of the house in every single room. Glazing must be used strategically and smarter. Unless you have the money to invest in high performing triple glazed windows.

For instance, if your views are on the south or the west. Think about picture frame windows. To highlight and frame the view. And introduce a sill where furniture will be placed against a wall. Allow more wall space for artwork or furniture. Be smart (money smart) and selective with your window and door openings. E.g. bi-fold doors cost more than stacker sliders. And stacker sliders cost more than standard sliding doors. French doors on the other hand are more cost effective than standard sliding doors. Choose your opening types wisely and reconsider if you really need huge sliding doors everywhere. Or could it be a large fixed panel with a hinged door instead? This can have a huge impact on your window cost.

I know, many are afraid of the cost implications of double glazing, and even more, so high performing double glazing. Luckily the glazing cost has come down significantly over the last few years. And I’m sure the prices will come down even further. It’s all about supply and demand and economy of scale. This is what happened in Germany a long time ago. And more recently in some parts of the USA. When double glazing became mandatory. Within a few months the prices for double glazing came right down. And now single glazing is even more expensive than double glazing in Germany. And triple glazing only costs a fraction more than double glazing. So there is hope on the horizon.

And it will be similar with other high-performance materials and insulation. The more suppliers and products are on the market, the more competitive the industry will get.

I think some designers or builders might be in for a shock. And they will have to rethink how they structure their design and processes.

Energy efficiency and the energy rating cannot be an afterthought. It’s not just a tick you need for your building permit. The performance of a house must be considered right from the start. In fact, the energy rating program should be used as a design tool to optimise and fine tune the design. Meaning the energy rater needs to get involved in the process much earlier.

In the past, we used first rate 5 to finetune to passive solar design of all our homes. But nowadays we prefer working with PHPP (The passive house planning package) Which we believe is a far superior tool to optimise the performance of a house. And fine tune the windows, insulation and the required shading.

So, what is the biggest takeaway? What are the things you need to look out for if you want the transition from 6 to 7 star as smooth as possible?

Passive solar design is a must

Use the energy rating program as a design tool > work closely with a energy rater throughout the project

And whilst I think the proposed changed to the building code are not quite enough yet to improve the way our homes are built here in Australia. But it is a step into the right direction.

I’m still hoping the next step will be to look at the actual performance of the house. Making sure the houses are built as per the theoretical energy rating. And that quality assurance of the thermal performance will be taken more seriously.