New Zealand banks have been urged to catch up with international trends and offer special low interest loans to people building eco-homes.
One Auckland couple have been pushing the change which they say will improve the country's cold drafty housing stock.
Rochelle and Joel Payne are completing the Living Building Home Challenge - the highest green building certification in the world.
Once complete, their Beachland suburb property will be the first New Zealand home to achieve this standard.
The house is being built out of rammed-earth and designed to be completely self-sufficient with all power generated on site, compostable toilets and waste water treatment.
But when hunting around for a mortgage, the couple were shocked to find no New Zealand banks offer loans with lower interest rates for green builds.
Lower interest loans for green builds are available in other countries including Australia.
If banks offered eco-loans, it would encourage more people to build sustainably, Rochelle Payne said.
"We're pushing the boundaries and struggling and we would like to see banks supporting it because a lot of these projects do have additional costs so anything you can get back with extra help and support with a lower interest rate or even a bigger cash-back or better terms it would all really help and push New Zealand towards its goals," she said.
The couple did finally manage to get a local bank to back them and have since completed the basement and some of the rammed-earth walls.
The appetite for green building isn't here yet because people don't understand what a quality home looks like, Ms Payne said.
"A lot of people still don't understand the basics of what a green building is; they still don't understand what a warm, comfortable, dry home should be or what that would actually look like in reality which is possibly where a lot of our homes are falling down and why green building isn't really taking off because there is a massive lack of understanding of what that is and what that means," Ms Payne said.
Architect Bob Burnett faced similar hurdles with banks when building the first 10-Homestar rated house in New Zealand three years ago.
There is a lack of demand for eco-loans because people are building homes to code thinking that is the best standard, Mr Burnett said.
"There will be a lot of people out there that aren't aware, they think that a new home is going to be the latest and greatest just like a new car but a new home in New Zealand is 30/40 years out of date, you know, we don't drive around in Ford Escorts or Morri-Minors anymore - we wouldn't accept that so why do we accept that for our homes?"
Mr Burnett is in the process of creating what he calls a "Housing Dashboard" - a 3D tool which will allow people to see how adding solar or insulation can improve their home. It will even show people how many trips to the doctor or days off work they will need because of health problems from living in cold, damp or mouldy homes.
The government need to do more to improve housing, he said.
"We are an embarrassment, we are a laughing stock to the world when people look at how we live and the homes that we live in and there's definitely a role for the government to pull their socks up.
"There needs to be incentives and there hasn't been any, it has just been hands off, let market-forces decide what happens with housing and we've seen how well that's worked," Mr Burnett said.
Of the five major banks only ANZ and the BNZ said they are looking into eco loans.
Kiwibank and Westpac offer incentives for renewable energy systems and insulation costs.