Australia’s solar story has so far been written largely through detached housing. More than one in three Australian homes now have solar, yet apartments remain almost entirely outside that shift. Nationally, around one in six homes is an apartment, and that share is growing. Just 10 years ago, it was closer to 10 per cent. The upward trend is clear.
Despite this growth, solar uptake in apartments has remained opaque. Reliable data on how many apartment buildings boast solar is scarce, perhaps because that figure remains well below policy ambitions. It’s often even inflated to include apartment buildings with solar only for common areas. Yet this underrepresented market is where developers are starting to unlock new value, for reasons explained by the Domain Sustainability Report.
In 2025, the property body found that energy-efficient houses are attracting substantial premiums over comparable non-energy-efficient homes, with Melbourne recording the strongest uplift at 23.8 per cent. Solar is the single biggest feature within that mix, contributing an average uplift of $140,000 nationally.
For a market where apartment owners have historically had limited access to rooftop solar, this raises a clear question: If solar has added so much value in the detached housing market, what happens when apartment buildings are finally designed to capture the same benefit?
Lower power bills remain the most immediate benefit, but they are only part of the equation. Increased buyer appeal and a closer alignment with the direction of Australia’s renewables mix sit alongside the direct savings case for both user and policy groups.
One of the technologies seeking to close the gap is Marshall, created by ZECO Energy as part of its vision to make renewable energy accessible to all.
Now operational in apartment buildings across Victoria and Queensland, Marshall began as an engineering solution to frequent compliance issues on conventional residential solar sites. It has since evolved into a broader B2B platform used across hundreds of complex sites, before being adapted further for multi-dwelling applications.
In apartments, its role is to make shared solar workable in environments where compliance, metering, and control all become significantly more complex.
“People living in apartments have been left out.
A recent installation of Marshall across 36 apartments
in Magnetic Island, Queensland.
Some buildings have had solar installed, but there’s still a remarkable amount that haven’t,” says ZECO Energy director Ian Lilley.
“Our technology allows us to reach out to a lot more apartment owners with a compelling pitch and a promise that something can actually be done.”
According to Lilley, two clear barriers consistently stall projects: network compliance and collective decision-making within existing buildings.
“The compliance side has become a disaster, and this is often what prevents projects before they even start,” he says.
“There’s so much red tape to cut through just because these aren’t mainstream solutions just yet. Dealing with network constraints, switchboard upgrades, and metering arrangements, there are so many layers and so much engineering work that needs to go on that, in the past, hasn’t been as feasible.
“The other is the owners’ corporation and strata approvals. Given we’re installing on a common roof, it’s not enough just to have a few residents band together. It’s our job to help educate and prove the solution, but in the end, it is up to the owners as a group to get everyone onside.”
This is where developers and builders now hold much of the power in solar solutions, not just existing strata communities.
In new projects, apartment solar can be integrated early, while the electrical architecture of the building is still being designed. This avoids one of the biggest cost burdens in retrofit projects: reworking the main switchboard and related infrastructure after the fact.
It also allows solar sharing, export control, battery readiness and EV readiness to be planned as part of a coherent system instead of being added later as separate layers.
ZECO senior engineer Janak Nambiar explains: “One of the highest costs of a project for us is integrating our Solar Sharing tech, Marshall, into the main switchboard.
“The real reason that this solution works so well for developers and builders is that we like to integrate our system into the main switchboard. At the building stage, the costs are far less. If we were retrofitting, we’d have the additional issue of redoing the main switchboard to suit Marshall, and that’s where the extra cost comes from.
“The finances still more than stack up, just not to the amazing levels of new builds.”
In practice, Marshall is designed to act as the control layer for multi-tenant energy sharing, enabling transparent solar allocation across tenants, export
control and compatibility with embedded networks, batteries and future electrification pathways.
Nambiar, who has submitted his final thesis for a doctorate in multi-dwelling unit solar, played a key role in establishing ZECO Energy’s flagship apartment project in Melbourne with Map Developments: six fully electrified units designed around shared solar, battery storage, and embedded energy coordination.
In this project, Marshall manages how energy is allocated between the apartments, the battery and the grid based on time of day, demand and stored capacity, keeping the system complexity invisible to residents.
“The residents don’t notice anything different except for no gas and electricity bills. The builder is thrilled with the boost in apartment values. It’s just a solution that works for everyone,” Lilley says proudly.
Beyond apartments, retirement villages may further prove one of the most compelling next applications for shared solar and battery architecture. These communities face similar challenges: one shared point of connection, multiple dwellings behind the meter, and complex compliance requirements that limit traditional solar deployment.
ZECO Energy believes the same control architecture developed for apartment solar can be extended naturally into this setting, particularly where flexible energy allocation across a site is needed.
As consumer expectations shift and Australia accelerates towards deeper renewables, technologies like Marshall are positioned to unlock a new layer of value across a residential market still in its boom.
