Selling a House With Solar: What You Need to Know

Selling a house with solar in New Zealand is usually a straightforward win: if you own the system outright, the panels, inverter, and any battery transfer with the property at no extra cost to either party, the warranties shift to the new owner with a short form, and Consumer NZ research consistently suggests solar adds buyer appeal in a competitive market. The complications appear when the system is financed (a green loan still attached to your mortgage) or, less commonly now, leased (a third-party owns the kit on your roof). Sort the ownership question first, gather your documentation second, and brief your real estate agent third. Do those three things and your solar becomes a selling point, not a sale-stopper.

This guide is for Kiwi homeowners about to put a house on the market with a rooftop solar system, whether it's a 3 kW starter array from 2018 or a 10 kW system with a battery installed last summer. We'll cover what transfers, what doesn't, how to handle the paperwork, and the awkward edge cases (lapsed warranties, SolarZero customers, dodgy install records) that can trip up a settlement.

We won't cover the question of whether solar adds dollar value to your sale price in detail here, that lives in our companion piece on whether solar increases property value. This article is the practical, "what do I actually have to do" handbook.

What Selling a House With Solar Actually Means for NZ Homeowners

In New Zealand, residential solar is treated as a fixture in almost every case. That means the panels, inverter, wiring, isolators, and any roof-mounted hardware are part of the house under the standard ADLS (Auckland District Law Society) Sale and Purchase Agreement. They stay with the property unless you specifically exclude them in the contract, which would be unusual and, frankly, daft.

A home battery (Tesla Powerwall, BYD, sonnen, etc.) is a bit more nuanced. If it's hard-wired and wall-mounted in the garage or laundry, it's a fixture too. A portable plug-in battery would be a chattel and would need to be listed on the chattels schedule if you wanted to leave it.

The four practical questions every selling homeowner needs to answer:

• Do I own the system, finance it, or lease it? This changes everything.
• Where is my paperwork? Install certificate, warranty docs, monitoring login.
• What do I tell my buyer's solicitor and my real estate agent?
• How do I transfer the export agreement with the electricity retailer (Genesis, Mercury, Contact, Meridian, Octopus, Ecotricity, Frank)?

Get clear on these and the rest is admin.

Owned vs Financed vs Leased: The Three Scenarios

The single biggest factor in how messy or smooth your sale will be is how you originally paid for the system. Let's walk through each.

Scenario 1: You Own the System Outright

This is the cleanest situation and covers the majority of Kiwi solar homes. You paid cash, paid off the original loan, or rolled it into a mortgage refinance years ago. The system is yours, free and clear.

At settlement, the solar simply transfers with the house as a fixture. There is no separate bill of sale, no transfer fee, no third-party approval needed. Your job is to hand over a clean documentation pack (we cover what's in it below) and make sure the buyer can register the system in their name with their chosen electricity retailer.

That's genuinely it. The paperwork takes maybe an hour of your time across the entire process.

Scenario 2: You Financed the System (Green Loan or Top-Up)

This is increasingly common as more Kiwis use bank green loans (Westpac, ANZ, BNZ, Kiwibank) or general mortgage top-ups to fund solar. The system itself is yours, but there's still debt attached to your name.

Here's the critical thing: the loan stays with you, not the house. The green loan or mortgage top-up was secured against your property or your income, not against the solar hardware specifically. When you sell, the loan gets settled out of the sale proceeds, just like the rest of your mortgage. The buyer gets the system free of any encumbrance.

You don't need the bank's permission to sell, and you don't need to involve them in the solar conversation beyond your normal mortgage discharge. Some sellers worry the bank will treat the solar loan separately, they won't, if it was structured as a mortgage top-up or a green loan secured against the property.

If you're not sure how your finance was structured, ring your bank's home loan team and ask: "Is my solar loan secured against the property, and will it discharge at settlement?" Most will say yes immediately. If you took a personal unsecured loan separately, that one stays with you personally and has nothing to do with the sale. For future buyers wanting to understand finance options, the Solar System Cost & ROI Calculator is a useful pointer.

Scenario 3: You Have a Lease or PPA Arrangement

This is the trickier one, and it's the scenario that most affects former SolarZero customers and a small number of other PPA-style (Power Purchase Agreement) households.

Under a lease or PPA, a third party owns the panels on your roof. You pay them a monthly fee, or buy the power they generate at a set rate, often for 15-25 years. When you sell, the buyer must either:

• Take over the contract, agreeing to keep paying the monthly fee for the remainder of the term
• Buy out the contract, paying a lump sum to release the property from the agreement
• Or in some rare cases, have the panels removed (usually at significant cost)

Real estate agents will tell you bluntly: an unfamiliar lease attached to a house can scare buyers off or grind negotiations to a halt. If you're in this situation, start the conversation with the third-party owner before you list. Get the buyout figure in writing. Get the transfer paperwork pre-approved.

If you were a SolarZero customer and you're feeling unsure about where things sit after their administration, that situation is genuinely complex and we'd point you toward our dedicated SolarZero support content rather than improvising answers here.

The Documentation Pack: What to Hand the Buyer

A well-prepared documentation pack does three things: it speeds up the buyer's solicitor's due diligence, it transfers warranties cleanly, and it signals to the market that you've looked after the system. Estate agents love this stuff because it removes friction.

Your pack should include:

• Electrical Certificate of Compliance (CoC) from the original install, this is the legal document proving the system was installed by a registered electrician to AS/NZS 5033 standards
• Original invoice and itemised quote showing panel brand and model, inverter brand and model, battery details if applicable
• Warranty documents for panels (typically 25 years), inverter (typically 10-12 years), battery (typically 10 years), and the installer's workmanship warranty
• Monitoring app login transfer instructions (Enphase Enlighten, SolarEdge mySolarEdge, Sungrow iSolarCloud, Fronius Solar.web, etc.)
• Most recent annual production data from your monitoring (a screenshot of the last 12 months of kWh generated)
• Any maintenance/cleaning records if you've had the system serviced
• Distributor approval letter from your local lines company (Vector, Wellington Electricity, Orion, Powerco, Aurora, WEL, Top Energy, Unison) confirming the system was approved for grid connection
• Current export agreement details with your electricity retailer

If you've lost the originals, your installer should be able to reissue most of them. If the installer has gone out of business, your lines company keeps records of grid-connection approvals, and the inverter manufacturer can usually re-verify warranty status from the serial number.

Transferring Warranties: How It Actually Works

Most NZ solar warranties are transferable to subsequent owners without any cost, but the process varies by component.

Panel warranties (Trina, JinkoSolar, LONGi, REC, Q CELLS, etc.) almost always transfer automatically with the property. The warranty attaches to the serial number, not the original purchaser. The buyer simply keeps the documentation in case of a future claim.

Inverter warranties (Fronius, Sungrow, SolarEdge, Enphase, Goodwe) usually transfer automatically too, but some brands require a quick online registration in the new owner's name. Five minutes on the manufacturer's website handles it.

Battery warranties (Tesla, BYD, sonnen) are the most likely to require formal transfer paperwork. Tesla Powerwall warranties, for example, attach to the property address but should be re-registered to the new homeowner via the Tesla app within 30 days of settlement. Skip this and a future warranty claim can get messy.

Installer workmanship warranties (the labour and roof-penetration warranty, typically 10 years from a reputable installer) are the trickiest. Some installers honour them for any owner of the property; others tie them to the original customer. Ring your installer and ask, get the answer in writing.

The buyer's solicitor will often request this paperwork during the conditional period. Having it ready saves days of back-and-forth.

Switching the Export Agreement

When you sell, your electricity account closes and the buyer opens their own. The solar export buy-back rate doesn't automatically transfer, the buyer chooses their own retailer and their own plan, which may or may not match yours.

This is genuinely useful information for buyers, because the buy-back rate they get is plan-dependent and varies widely between retailers. Some plans pay a flat rate, others offer dynamic time-of-use rates that pay more during peak demand. We keep the current state of buy-back rates in our solar ownership guide, point your buyer there if they ask.

What you should do as the seller:

• Notify your retailer of the settlement date and request a final bill
• Confirm with the buyer that they've chosen their own retailer and arranged solar export from settlement day
• Provide the buyer with your ICP number (Installation Control Point, found on any power bill), this is the unique identifier for the property's grid connection

If there's a gap between your account closing and theirs opening, the export simply doesn't get credited for those days, no big drama, but worth coordinating to avoid wasted generation.

What This Means for You

If You're the ROI Pragmatist

Your instinct is "did I actually get my money back?" Solar adds buyer appeal in a market where electricity prices are doing what electricity prices do (steadily upward, per MBIE energy price data). Even a 5-year-old system with 20 years of panel warranty left is a tangible asset that lowers the buyer's future operating costs.

Don't try to extract the full original cost of the system from your sale price, that's not how housing markets price fixtures. But do brief your agent to feature the system as a selling point, supply the production data, and let the market reward you.

If You're the Tech-Savvy Optimiser

Your buyer almost certainly won't be as into the kit as you are, that's fine. Write a one-page summary: panel make and model, inverter, battery if any, average annual kWh generated, monitoring app login process, and any quirks (e.g. "the morning shade window means the east-facing string underperforms in winter, the west-facing string carries the system from 1pm onward").

This kind of handover note is genuinely rare and genuinely useful. Buyers remember it.

If You're the Eco-Conscious Family

You probably want to know the system will continue doing its job under the new owner. The best thing you can do is leave a clean documentation pack and a recommendation for the buyer to keep up with basic maintenance, our cleaning and maintaining solar panels guide is a fair pointer to leave with the house.

Common Pitfalls (What Real Estate Agents and Installers Don't Always Tell You)

Pitfall 1: Assuming your buyer's bank will value the solar. Bank valuers in NZ are mostly conservative about adding dollar value for solar in formal valuations. The market may reward you in the sale price, but a registered valuer's report often won't add a specific line item. Don't bank on a valuation bump for refinance purposes.

Pitfall 2: Letting your monitoring app log in expire. If you stop paying attention and the inverter goes offline for a year, you won't notice if production has dropped. A buyer's pre-purchase inspector who checks the inverter and sees fault codes will use it as a price negotiation lever. Our guide on troubleshooting solar output drops is worth a read before listing.

Pitfall 3: Not disclosing a leased system. If your panels are leased or under PPA, you must disclose this. The buyer's solicitor will find out anyway, and undisclosed encumbrances can sink the contract. Be upfront from day one.

Pitfall 4: Letting your installer "do the transfer for a fee". Some less scrupulous installers offer to "transfer the system to the new owner" for a few hundred dollars. This is, for owned systems, not a real service. There's nothing to transfer beyond the documentation pack and the warranty registrations, which you can do yourself for free.

Pitfall 5: Roof penetration warranties. If your roof has been re-roofed since the solar install, your original installer's roof-penetration warranty may be void. Check this before listing, because a future leak claim could land on the buyer (and embarrass you).

Pitfall 6: Going hard on "system will pay for itself" marketing. Real estate agents sometimes oversell solar to a buyer in a way that creates post-settlement disputes. Provide actual production data, not aspirational claims. Honest data builds trust and protects you from later complaints.

Frequently Asked Questions

Do I need to inform my electricity retailer when I sell?

Yes. You'll close your account at settlement and the buyer opens theirs. The solar export agreement is plan-specific to whoever holds the account, so the buyer will need to either join your retailer on a comparable plan or shop around.

Does solar add to the sale price of my house in NZ?

Consumer NZ and various agent surveys suggest solar increases buyer appeal and can support a higher sale price, especially in competitive markets, but registered valuers are typically conservative about assigning a specific dollar uplift. The honest answer: it helps you stand out, it lowers buyer hesitation, but don't expect a line-item bump on a bank valuation.

What if my installer has gone out of business?

Panel and inverter warranties are with the manufacturer and remain valid regardless of installer status. You can reconfirm warranty status by giving the serial numbers to the manufacturer. Workmanship warranties from a defunct installer are unfortunately gone, this is a real risk of buying from very small or short-lived companies.

Can I take the panels with me to my new house?

Technically yes, practically almost never worth it. Removal and reinstallation costs typically run $3,000-$6,000, plus re-permitting with the new lines company, plus potential roof damage to the old house (which you'd then have to repair as the seller). In every realistic scenario, leave the system, factor it into your sale price.

What happens to my battery warranty when I sell?

Most home batteries (Tesla Powerwall, BYD, sonnen) have warranties that follow the unit and require re-registration to the new homeowner within a short window, often 30 days. Tesla specifically requires the new owner to claim the Powerwall in the Tesla app. Make this clear in your documentation pack so the buyer doesn't miss the window.

Do I need a builder's report or special solar inspection before selling?

You don't need a special solar inspection. A standard pre-listing builder's report will note the presence of solar; some inspectors will check for visible damage or obvious fault codes on the inverter. If your system is more than 8-10 years old, a quick service call to confirm everything is working can be a useful pre-listing investment.

I'm a former SolarZero customer. Where do I stand?

This depends on the specific arrangement you signed and the current state of the administration process. The general principle: a third-party-owned system on your roof is a contractual encumbrance that needs to be addressed before sale. We'd point you to dedicated SolarZero support content rather than risk guessing about a fluid situation. Speak to a property lawyer early.

Should I mention solar in the listing or save it for the open home?

Mention it. Buyers searching for solar homes are out there, and the listing description is where they filter. Include the system size in kW, presence of a battery if you have one, and the approximate annual production. Specifics build credibility.

What if my buyer asks for the original purchase price of the system?

Share it. There's no reason to hide it. The original invoice is part of the standard documentation pack and helps the buyer understand what they're inheriting. It also lets them see what a comparable new system would cost today, which usually works in your favour because solar prices have come down significantly.

Where to Go From Here

If you're early in the selling process, the best next steps are: dig out your documentation, log in to your monitoring app to confirm production looks healthy, and have a quick conversation with your bank about how your solar finance (if any) discharges at settlement. Our Ownership & Aftercare pillar covers the broader picture of looking after a system across its life.

If you've spotted that your production data looks off, work through the solar output troubleshooting guide before listing, a healthy system is a stronger selling point. And if you want to confirm your monitoring is set up cleanly for the handover, the monitoring app guide walks through the major platforms.

If you're on the other side of this transaction, the buyer rather than the seller, our Solar System Cost & ROI Calculator can help you sanity-check the value of an existing system relative to a new one.