Why Mutual Banks Are Quietly Leading The Way In Green Home Loans

Robin Stam

5th May, 2025 | 5 min read

Blog / Green loans

If you have an energy-efficient home or are planning to enhance your home's energy efficiency with solar panels, better insulation, or full electrification, you could save significantly on your mortgage, with rates from 5.43%!

Many Australians are unaware that the best green home loan offers often come from mutual banks rather than the big banks. These smaller, customer-owned institutions are quietly transforming leading the way on green loans.

What is a mutual bank?

A mutual bank is a customer-owned financial institution. Unlike the big four, which are owned by shareholders and driven by profit returns, mutual banks are owned by their members. If you have an account, you're effectively part-owner of the bank.

This structure shapes everything from the products they offer to the way they operate. Because mutual banks don’t have to deliver profits to external investors, they reinvest earnings into:

Lower interest rates
Fairer fees
Great customer service

They also tend to be deeply embedded in their communities, making them more attuned to the social and environmental challenges their customers face.

The best mutual bank green home loans of 2025

Here are four of the most competitive green home loan offers from mutual banks in 2025:

Gateway Bank – Green Plus Home Loan

5.60% Variable rate
Minimum NatHERS or Residential Scorecard rating of 7 stars.
Do you have solar? Your rating is likely over 7 stars already!

Summerland Bank – Eco Home Loan

5.59% Variable rate
Have five home energy upgrades installed on the property, such as solar panels, batteries, heat pumps, insulation, or any other home energy upgrade?
Existing and new homes.

Bank Australia – Clean Energy Home Loan New Build - 5.43% variable

5.43% Variable rate.
For newly built homes
Homes with a NatHERS rating of 7.5+ and solar.

Bank Australia – Clean Energy Home Loan Renovate

Note: This loan is temporarily paused - Learn more

5.13% Variable rate
Offers a substantial 5-year rate discount for homeowners who have upgraded an existing property.
Three upgrades in the last 18 months or a 1-star increase of the Residential Scorecard
Backed by the CEFC.

Why mutual banks offer the best green mortgages

Mutual banks aren’t built to chase shareholder returns or quarterly profit targets. Their business model is grounded in a simple idea: serve members, not markets.

This purpose-driven structure shapes how they operate, what they prioritise, and where they reinvest profits. The result? Products and services that often deliver better outcomes, not just financially, but in terms of community value. Here’s how that plays out in practice:

Better rates
Mutual banks can offer lower interest rates on home and personal loans without pressure to maximise margins.
Longer-term thinking
Mutual banks don’t need to satisfy investor expectations every quarter. They can invest in programs and partnerships like those with the Clean Energy Finance Corporation that may take time to mature but deliver meaningful value for members.
Stronger alignment with customer values
Many mutual banks have ethical investment policies, avoid fossil fuel financing, and support local initiatives. This isn’t a marketing afterthought, it’s a reflection of their structure and their members' priorities.

How to access green home loans through mutual banks

Mutual banks in Australia offer some of the most competitive green home loan products available. These loans provide discounted interest rates to individuals who build, own, or upgrade homes to improve energy efficiency.

To qualify for these loans, your home typically needs to meet specific criteria, such as achieving a 7-star energy rating or including upgrades like solar panels, heat pump systems, or insulation. While this may seem complex, it is often pretty straightforward. Many Australians (over 4 million households) have already installed solar, putting them well on track to meet the eligibility requirements.

At 28Watt, we simplify the process. As a specialist green loan broker, we evaluate your property and determine which upgrades can help you qualify for a loan. If you've already made upgrades, that's fantastic, you may already qualify.

If you're considering additional upgrades, our online home energy assessment will tell you the costs of the upgrades and the energy bill savings you'll achieve. If you’re ready, we can connect you with one of our trusted installation partners, or you can choose your own. Once your home meets the requirements, we’ll streamline the green home loan discount application.

We handle the entire process so you don’t have to worry about the paperwork.

Common myths about mutual banks

Mutual banks don’t have modern services
Most mutual banks offer digital banking, mobile apps, and broker integration. Their customer service is often rated more highly than the majors. While they may not have branches on every corner, they offer personal and responsive support when it counts.

They are harder to access
If you’re refinancing or applying through a broker, you don’t need to be a long-time customer. Many mutual banks welcome new borrowers upgrading their homes and looking for values-aligned finance.