Where I Spent and Saved Building an Energy Efficient Home

Building an energy efficient home doesn’t mean spending more money on absolutely everything.

One of the biggest things I learnt building our home was where spending more would actually make a difference, and where it wouldn’t.

Our home achieved an 8.3 star NatHERS rating, but we certainly didn’t choose the most expensive option at every turn. I’ve shared more about how we achieved the rating in Building an 8 Star Energy Efficient Home.

Now that we actually live here, these are the areas where I think spending more was worth it, and where I’m glad we saved.

WHERE I SPENT MORE

Double glazed windows

This was absolutely somewhere I was prepared to spend more.

We used double glazing throughout, but it wasn’t simply about buying better windows. Their size, placement, orientation and shading were all considered as part of the design.

There’s little point paying for high performing windows and then putting huge expanses of glass in all the wrong places.

Would I spend the money again? Absolutely.

Insulation

Insulation isn’t particularly exciting when you’re choosing all the beautiful parts of a new home, but once the walls are closed up, you don’t get another easy opportunity to improve it.

We used R2.3 under the slab, R2.7 in the external walls and R6 in the ceiling, plus acoustic insulation internally in selected areas.

It’s money you don’t see, but you definitely experience once you live in the house.

Airtightness

Another thing nobody sees!

We used a quality Pro Clima building wrap and paid attention to sealing and taping the house.

Good insulation is only part of the equation. Reducing uncontrolled air leakage helps the whole building envelope perform better.

For me, this was worth spending money on while we had the opportunity.

Orientation

This one didn’t necessarily cost us more, but it may be one of the most valuable decisions we made.

Our main living areas face north and open onto a northern courtyard, allowing us to take advantage of winter sun while controlling the harsher summer sun.

If you’re still designing your floor plan, get this right before worrying about finishes.

Good orientation is free once the house is built.

Solar

Our house is all electric and we installed a 13kW solar system.

It was a considerable upfront investment, but I wanted to think beyond the cost of building and consider what the house would cost us to run for years afterwards.

WHERE I SAVED

Fewer downlights

I didn’t want a ceiling covered in downlights, so we used lighting much more deliberately.

Wall lights, pendants and task lighting give us light where we actually need it, while also making the house feel much nicer at night.

Less technology

I didn’t want to rely on expensive technology to make a poorly designed house perform better.

The fundamentals came first:

Orientation. Insulation. Glazing. Shading. Airtightness. Cross ventilation.

Technology can complement a good house, but I don’t think it should have to compensate for a bad one.

A simpler material palette

You don’t need an expensive finish on every surface.

I repeated materials and colours throughout our house, then chose particular areas where I wanted to spend more.

This helped keep the house cohesive while allowing us to put more of the budget into the things that would actually affect its performance.

WHERE SHOULD YOU SPEND YOUR MONEY?

If you’re building an energy efficient home on a budget, I wouldn’t start with:

“What energy efficient products should I buy?”

I’d start with:

“How can I make the house itself work harder?”

Get the floor plan and orientation right first. Then concentrate your budget on insulation, glazing, airtightness and shading.

Some of the best decisions we made aren’t the things people notice when they walk through our front door.

They’re the things we notice every day when we live here.

And that’s where I think the money is worth spending.

Planning an energy efficient home?

I’ve put everything I learnt designing and building our 8.3 star NatHERS rated home into my Energy Efficient Home Guide.

It’s designed to help you make smarter decisions before you build, when those decisions can make the biggest difference.