Buying a Queensland Home With Solar Already Installed: What to Check Before You Sign

A house with solar already on the roof looks like a head start. The panels are paid for, the inverter is humming, and the agent's listing mentions lower bills. Sometimes that is exactly what you are buying. Sometimes you are buying someone else's expiring warranty, an inverter due for replacement, a leased system you do not own, or a roof that has not been inspected since the panels went up.

Queensland is a particular hotspot for this question, with solar on a very large share of homes and a mix of older systems installed under generous early feed-in arrangements and newer systems sized for self-consumption. The checks below are written for a Brisbane or Queensland purchase, where the network operator is Energex in South East Queensland and Ergon Energy in regional Queensland, and where the difference between a good inherited system and an expensive one usually comes down to paperwork, not panel count.

This guide is general information, not legal, conveyancing or tax advice for any particular purchase. Confirm title, contract and connection details with your conveyancer, electrician and the network operator for the specific property.

1. First, establish who actually owns the system

Owned outright, leased, or under a power purchase agreement? Most inherited systems are owned outright and pass with the house, but not all. Some systems were installed under a lease or a power purchase agreement (PPA), where a third party owns the equipment and the household pays for the electricity it produces, or pays a lease charge, for a fixed term. A leased or PPA system can come with a contract term that survives the sale, a buyout figure, removal conditions, or a roof licence that binds the new owner. Ask for the ownership documents before you exchange contracts, and ask your conveyancer to confirm in writing whether any solar contract is included in the sale, excluded, or to be discharged at settlement.

Is there a loan secured against the system? A system bought on finance may have a loan that the seller is expected to clear at settlement, or — less commonly — a finance arrangement tied to the property. Do not assume it is cleared. The contract and the settlement statement should answer that question, and if they do not, ask.

Who is the electricity account holder, and what tariff is the system on? The seller's retail tariff and feed-in arrangement do not automatically transfer to you in the same form. In South East Queensland, retailers set their own feed-in tariffs, often only a few cents per kilowatt-hour; in regional Queensland, Ergon's regulated feed-in rate was 6.006 cents per kilowatt-hour from 1 July 2026, set by the Queensland Competition Authority. An older system may have been on a legacy premium feed-in tariff that has since closed to new entrants, and a buyer should never assume a premium rate transfers. Ask the seller for recent bills, and ask your chosen retailer what tariff and export arrangement will apply to you at that address, on that meter, with that system.

2. Age matters more than panel count

Panels, inverter and battery age at different rates. Australian Government guidance on warranties and insurance notes that many solar panels carry a product warranty of 10 to 15 years, with good-quality modern panels expected to last at least 20 years, while string inverters commonly carry a 5 to 10 year warranty and will usually need replacement before the panels. A 12-year-old panel array may still have years of useful life; a 12-year-old string inverter may be at or past its expected life, and its replacement is a real cost to budget for, not a surprise to discover in your first summer.

Ask for the installation date, not just the panel brand. The installation certificate, the inverter label, the original quote and any monitoring history together give you the system's real age. A listing that says "solar installed" without a date, a size in kilowatts, or a brand and model tells you almost nothing. A 6.6 kW system is a common Brisbane size, but the figure that matters for your bills is what the system actually generates, when it generates it, and how much of that generation your household can use during the day.

Get the generation history, not a sales estimate. Ask for 12 months of monitoring data or inverter logs, and recent electricity bills showing imports, exports and any solar credits. A system that generated well three years ago but has a string down, a failed optimiser or a shaded section today will not show that in a brochure. Output that falls well short of a reasonable expectation for the system's size, orientation and location is a reason for an inspection, not a reason to accept the seller's bill estimate.

Check	What good looks like	Red flag
Ownership	Written confirmation the system is owned outright and included in the sale	Lease, PPA or finance mentioned but no contract supplied
Age and size	Installation date, panel and inverter brand and model, system size in kW	No date, no brands, only "solar installed" in the listing
Inverter	Age inside its warranty, or a budgeted replacement cost if older	Inverter older than its warranty with no replacement allowance
Generation	12 months of monitoring or bills matching the system's size and orientation	No data, or output far below expectation with no explanation
Roof	Recent roof and mounting inspection, no leaks or cracked tiles under the array	Water stains, lifted tiles, or no inspection since installation
Connection	Energex or Ergon connection approval for that system at that address	Approval missing, system enlarged after approval, or export arrangement unclear
Battery (if fitted)	Age, usable capacity, warranty remainder and throughput terms	Battery age unknown, capacity never tested, warranty documents missing

3. Warranties: four different promises, not one

Panel product warranty, panel performance warranty, inverter warranty and workmanship warranty are separate. The product warranty covers faulty panels; the performance warranty typically promises a declining percentage of original output over about 25 years — Australian Government guidance gives the common example of 90% up to 10 years and 80% up to 25 years; the inverter warranty covers the inverter for its own, usually shorter, term; and the workmanship warranty, usually around five years, covers the installation itself, including roof penetrations. A seller who says "25-year warranty" may be describing only the performance warranty, while the product and inverter warranties have already expired.

Does the warranty transfer to you? Some manufacturer warranties transfer with the property automatically; others require registration, a transfer form, or proof of the original installation. Without the paperwork, a warranty claim can fail on evidence even when the product is genuinely faulty. Ask for the warranty documents for every component, and confirm transfer requirements with the manufacturer or the installer's successor before settlement, not after a fault appears.

What if the installer has gone? This is the solar-orphan problem, covered in a separate EServices4U guide: the installer may have closed while the manufacturer warranties survive. In that case, a claim usually runs through the manufacturer, not the installer, and the paperwork matters even more. If the manufacturer has also left the Australian market, the warranty may be practically unenforceable even if it still exists on paper — a risk a buyer should price, not ignore.

4. The roof, the switchboard and the connection approval

The roof is the system's foundation, and it is hidden by the system. Panels sit on rails fixed through the roof. A roof that was old when the panels were installed, or that has suffered hail or storm damage since, can hide cracked tiles, lifted fixings or water entry under the array. In Brisbane's hail and summer storm climate, an inspection after severe weather is good practice for any solar owner, and it is essential for a buyer: budget for a roof and mounting inspection by a suitably qualified person, and check whether the building insurance has been updated to include the solar system at its replacement value.

The switchboard and meter tell you whether the system can grow. An older switchboard may need upgrading before a battery is added, an inverter is replaced, or an electric vehicle charger is installed. Ask whether the system has a smart meter, what export limit applies, and whether the connection is a fixed or dynamic (flexible) export arrangement. In Queensland, SolarQuotes' September 2026 summary of Energex and Ergon rules describes a single-phase fixed connection at 10 kW total inverter capacity with 5 kW export, a single-phase dynamic connection at up to 10 kW export, and a SWER fixed connection at 10 kW total with 2 kW export — but those are network rules, not a promise for any particular address. The connection approval for the specific property is the document that matters, and a system enlarged after approval, or installed without approval, is a compliance and insurance question, not a detail.

Batteries add their own checks. If the house has a battery, ask its age, usable capacity in kilowatt-hours (not just its nameplate figure), warranty remainder, any throughput or cycle limit, whether it provides backup during an outage and, if so, which circuits it backs up, and whether it was installed under the federal Cheaper Home Batteries Program, which began on 1 July 2025. A battery that has lost significant capacity, or whose backup circuits do not cover the loads a buyer assumes, is a different asset from the one in the listing.

5. What the system is worth to you — and what it is not

Value it on your load, not the seller's bills. A household that is home during the day, runs a pool pump, air conditioning or a home office, and can shift load into sunlight hours will get more value from the same system than a household that is out all day and imports most of its evening power at a retail price. Recent market guides put the typical Energex-area median feed-in value around 2 cents per kilowatt-hour at 30 October 2026, while retail import prices are far higher — which is why self-consumption, not export income, usually drives the value of an inherited system. Any valuation that treats export income as equal to import savings, or that promises a payback figure, should be treated as a claim to verify against your own load and tariff, not as a fact.

Dated update, October 2026. From 1 October 2026, the Clean Energy Regulator expanded Small-scale Renewable Energy Scheme eligibility for mid-scale solar from 100 kW to 1 MW, with applications expected in mid to late November 2026. That change matters for larger commercial roofs; it does not change the value of an existing residential system on a house you are buying, and it does not create a new rebate for a system that is already installed. Do not let a seller or agent present a scheme change for new commercial systems as a benefit of an existing home system.

6. How Both Sides Win

The buyer wins when the purchase price reflects the system's real remaining life: documented ownership, warranties that transfer, an inverter with life left or a priced replacement, a roof that has been inspected, and a connection approval that matches what is actually on the roof.

The seller wins when the same documents are ready before listing, because a buyer who can verify the system does not need to discount for the unknown — and a buyer who cannot verify it will discount for everything at once, or walk away.

The conveyancer and the agent win when solar is treated as part of the property due diligence, not as a marketing line: ownership, contracts, warranties and connection approval in the contract pack, answered in writing, before exchange.

7. What EServices4U would check independently

• Pre-purchase technical due diligence — system age, brands and models, inverter life, generation history, roof and mounting condition, switchboard and meter, connection approval and export arrangement, battery condition where fitted — from $299 as a solar and battery feasibility assessment, or from $149 for a residential quote review where that scope fits.

• Quote and tender comparison — where the buyer plans to replace an inverter, add a battery or enlarge the system, checking that competing proposals cover the same scope, warranties and connection work.

• Home Owner's Engineer services — from $599 — where that scope fits a particular engagement, including an independent engineering review of the inherited system and any proposed upgrade.

• Commercial Infrastructure Assessment / RPEQ & RPEV SLD Sign-Off — from $495 — where the engagement scope requires it, for larger or commercial premises.

Scope and the qualifications required for each engineering engagement are confirmed before work starts. EServices4U does not sell installations and does not receive installer commissions, so the review is independent of any installer or seller.

Frequently asked questions

Does the solar system automatically come with the house?

Usually, if it is owned outright and the contract includes it — but a leased system, a PPA system, or a system under finance may not. Confirm ownership and inclusion in writing through your conveyancer before exchange.

Can I keep the seller's feed-in tariff?

Not automatically. Your tariff depends on your retailer, your meter and the connection arrangement at that address after settlement. Ask your chosen retailer what will apply to you, and do not rely on the seller's bill as a promise of your future credits.

What if the inverter is old but still working?

Budget for its replacement. String inverters commonly carry a 5 to 10 year warranty and usually need replacement before the panels. A working inverter past its warranty is not a fault, but it is a foreseeable cost that should be reflected in the price or in your post-settlement budget.

Should I get the system inspected before I buy?

Yes, where the purchase timetable allows. An inspection by a suitably qualified electrician or independent engineer, covering generation, inverter health, roof and mounting condition and connection paperwork, is a small cost against a house purchase and a large saving against an inherited fault.

What if the seller cannot produce any solar paperwork?

Treat the system as unverified. Price it as a system with unknown warranty, unknown age and unknown connection status, or make the paperwork a condition of the purchase. A system without documents is not worthless, but it is not worth the same as a documented one.

Get an independent check before you sign

• Start with a free 15-minute consultation to talk through your tender, system, building, or project and find out which fixed-fee review fits, if any. Call/WhatsApp 0480 001 498 or email growthpartner@eservices4u.com.au. No obligation, and it does not include a written report.

• Solar and battery feasibility assessment — from $299. See packages and pricing.

• Residential quote review — from $149. See packages and pricing.

• Home Owner's Engineer services — from $599. See owners engineer Australia.

• Commercial Infrastructure Assessment / RPEQ & RPEV SLD Sign-Off — from $495. See packages and pricing.

• EServices4U home — eservices4u.com.au. Quote — quote.