The Gruen Eco Design blog about how to convert your dream of an energy efficient home into a reality.

How to Chop Thousands off Your Passive House Build


As some of you might have heard. Our mission at Gruen Eco Design is to make energy efficient homes a staple in the Australian landscape. 

Everyone should have the right to live in a comfortable house that does not cost the earth!

Affordability is a key motivator for us. And hence, the mission for our very own home is to prove that you don’t have to spend an arm and a leg to build your passive house.

I don’t want to sugar-coat it. It is not all easy breezy. And we have been working for months with our builder to get the cost down. 

It’s not even because we could not afford to stretch the budget that far. But we do not want to overcapitalize. Even if we manage to get the build cost down to our target we will be overcapitalizing. And any additional money spent will make it worse.

We have been exploring options on how to save money.

I must say though, we are very fortunate. In the sense that we are going to use this house as a display home and for marketing. Meaning we have found many suppliers that will offer us a reduced rate. Yay.

Because of that, there are a lot of elements on the house that we will buy and/or manage ourselves. This means we don’t have to pay for the builder’s margin. 


We will organise and manage the demolition ourselves. Currently we are getting a few quotes. 

Fixtures, Fittings, Light Fittings & Appliances
We will be buying and supplying all the little things that go into the house ourselves. We’ve found a lot of great and simple LED lights in ikea that we will be using throughout. Our aim is to have indirect light in the entire house. Downlights are one of my pet hates. We are avoiding them. Instead we have wall lights in most rooms. Rounded up with a few pendant lights. In the living room and in the kitchen, we will be using track lights.

And while we are trying to save as much money as we can, we are not skimming on the quality. All light fittings will be LED. Our fridge, dishwasher and all other appliances will be to the highest available star rating. 

Luckily, we also have a great contact here. Another alternative is to search online for discontinued stock. Or leftovers on gumtree or ebay. We will be going for simple floor and wall tiles. Nothing fancy. A combination of white, light greys and timber. No feature tiles needed.

We are also thinking about paying for the windows ourselves. To save on the builders’ margin.
This is a bit tricky though. And not all builders might be on board with this. As it can raise issues with the builders’ insurance. We are getting triple glazed composite windows for the main house. With aluminium externally and timber internally. Not the cheapest options but it looks great. And for the studio will be getting double glazed upvc windows. To save a bit of money. But all windows will be certified passive house. 

HRV & Heat Pump
We will also organise our Heat Recovery Ventilation system and the heat pump.

Solar Panels 
We are not sure yet if we can afford solar panels and the batteries. But we will make sure the house is solar panel and battery ready. As we are planning to get an electric car in the future. 

Shower Screens & Mirrors
The initial estimate from the builder was over $9000 for the shower screens and mirrors alone. Mind you, we do have a total of 3 bathrooms. An ensuite, a kid’s bathroom upstairs and a guest bathroom / toilet downstairs. (I didn’t want an ensuite bathroom. But this was something my partner did not budge on) 

We also have a small bathroom in our tiny house / studio. But we already have selected ready-made fixed shower screens. That only cost between $200 – $300 each. And we found nice round mirrors, that cost about $150. This is already a massive saving.

Again, we are lucky. As we will be getting a nice discount on these. 

When selecting your benchtop make sure you check from which range they are. There is a basic, mid, upper and a luxury range. And, there is a huge difference between these options. We had 2 that we liked. One from the upper range and one from the mid-range. Easy decision. Mid-range it was for us. 

Bathroom Fittings 
We will also organise toilets, sinks, vanities etc ourselves. We’ve found some nice, ready-made vanity units. With integrated sinks that look great and are cost effective.

Built-in Robes
All our built-in robes will be from ikea. We have designed the cavities in a way that they fit exactly the ikea robes. Where needed we will have little plasterboard nip walls. Ikea has a lot of options for external fit outs. Different kinds of drawers, hangers and storage solutions. 

Our kitchen carcasses will be ikea. But we will be getting the doors customised. As we don’t like their finishes that much.

Leaving Things Out Of The Contract
On top of that, we will also manage the landscaping ourselves. 

And we are considering doing the studio up to lock up stage. And then we can finish it off ourselves later. 

We are also contemplating to not build the pergola structure…

To summarise our efforts: 

It’s the little things that can make a big difference. 

There is no magic bullet.

Often, especially when you design a compact and simple home. There isn’t a magic bullet on how to save a lot of money. There isn’t the one major thing. No little trick. It’s not a matter of changing one thing and you save $50,000. It’s all those little things. $500 here, $1000 there, that add up and can accumulate to a lot of money. 


But you have to be careful not to take too much out of the builder’s contract either. Or you will end up with a big chunk of money that you might not have.

When we had put together our list of all the things, we wanted to pay ourselves we ended up way over $100,000. So, we had to put a few things back into the builder’s court.

We are still hoping to start construction later this year. Stay tuned!