We've been installing solar systems on landed properties since before it was fashionable, and we've watched the industry grow from a handful of serious installers to a crowded field where not everyone asks the right questions upfront. Most vendors will happily show you energy savings projections and government incentives. What they won't volunteer is whether your roof can actually carry the load, who's responsible when BCA rejects your submission, or what happens when your inverter dies two years after the warranty lapses. These are the questions we ask ourselves on every job — and the ones you should be asking any vendor before you commit.

Can Your Roof Actually Carry the Solar Load?

This is the first question we verify on every solar project, and it's shocking how many vendors skip it entirely. Solar panels aren't light. A typical residential system adds 15-20 kg/m² of dead load to your roof structure, sometimes more once you factor in mounting rails, ballast blocks (for flat roofs), and wind uplift reinforcement.

If your home was built before 2000, the roof may have been designed for minimal load — sometimes just enough for occasional maintenance access. We've had clients come to us after a vendor quoted them a full roof array without ever asking for structural drawings or conducting a load assessment. One case involved a 1980s terrace where the timber roof trusses couldn't safely take the proposed system without reinforcement. The vendor had already collected a deposit.

What to ask:

• Will you conduct a structural load assessment before finalising the design? They should either have a PE (Professional Engineer) review your existing drawings or arrange a site inspection to verify capacity.
• If my roof needs reinforcement, who handles that and at what cost? Some vendors will walk away. Others will subcontract it out at a markup. We handle this in-house because it's structural work — our core trade.
• What's the total load including mounting and safety factors? Ask for the number in kg/m² or kN/m², not just "it's fine."

Who Actually Handles the BCA and SP Group Submissions?

Installing solar on a landed property in Singapore requires approvals — from BCA for structural additions and from SP Group for grid connection. This isn't optional, and the process isn't automatic. We've seen vendors who treat this as an afterthought, handing clients a stack of forms and saying "your architect can submit this."

Here's the problem: if you don't have an architect or QP on retainer, you're now scrambling to find one mid-project. And if the vendor's design doesn't meet code — wrong setback from roof edge, insufficient fire separation, improper earthing details — the submission gets rejected and you're back to square one, often with panels already purchased and sitting in a warehouse.

We have in-house QPs, so when we quote a solar job, the price includes all submissions, revisions, and liaison with authorities. It's part of the build, not an optional add-on.

What to ask:

• Does your quote include all BCA and SP Group submissions, or is that extra? Get this in writing.
• Who is the QP signing off on the structural drawings? You need a name and PE registration number, not "we have connections."
• What happens if the submission is rejected? Who pays for the redesign? How long will it delay the project?
• Will you handle the SP application for grid connection and any export tariff registration? Some vendors install the system but leave you to figure out the grid paperwork yourself.

What's the Real Inverter Lifespan, and What Happens After?

Solar panels last 25+ years. Inverters don't. Most residential inverters have a functional lifespan of 10-12 years, sometimes less in Singapore's heat and humidity. Yet we regularly see vendors selling systems with 5-year inverter warranties and no conversation about what happens in year 8 when it fails.

This isn't a minor component. The inverter is what converts your panels' DC output into usable AC power. When it dies, your entire system goes offline until it's replaced — and replacement costs can run $2,000-$5,000 depending on system size, not including labour and downtime.

Some vendors will offer extended warranties for an upfront fee. Others will sell you a "premium" inverter with a 10-year warranty and imply it'll last forever. Neither is a substitute for an honest conversation about lifecycle costs.

What to ask:

• What's the expected functional lifespan of the inverter, not just the warranty period? These are different numbers.
• What does an inverter replacement cost, and is that model likely to still be available in 10 years? Some vendors use obscure brands that disappear, forcing you into expensive retrofits with new equipment.
• Do you offer maintenance contracts that cover inverter monitoring and replacement? If yes, what's the cost over 15 years? If no, who do I call when it fails?
• Is the inverter rated for Singapore's climate? Some cheaper units aren't built for high humidity and degrade faster.

What Are the Real Maintenance Requirements?

Vendors love to call solar "zero maintenance." It's not. Panels get dirty — especially in Singapore with rain, dust, bird droppings, and pollen. A heavily soiled panel can lose 15-25% efficiency, which eats directly into your ROI. Inverters need firmware updates. Mounting hardware needs periodic checks for corrosion and tightness, particularly after storms.

We've taken over systems from other installers where the homeowner was never told any of this. Three years in, the panels are caked in grime, the monitoring app hasn't worked in months, and output has quietly dropped by 20%. No one noticed because no one was checking.

What to ask:

• How often do the panels need cleaning, and do you provide that service? If not, who do I hire? Cleaning a roof-mounted array isn't a DIY job.
• Is there remote monitoring, and will you actively alert me if output drops? Passive monitoring (you check an app) is not the same as active alerts.
• What's the annual maintenance cost if I want you to handle inspections, cleaning, and inverter checks? Factor this into your payback calculation.
• Do you provide an as-built electrical schematic and O&M manual? If you ever need a different contractor to service the system, they'll need this documentation.

What's Your Warranty Actually Cover — and Who Enforces It?

Most solar vendors offer a bundle: 25-year panel performance warranty, 5-10 year inverter warranty, and some kind of workmanship guarantee on the installation. Sounds comprehensive until you read the fine print.

Panel performance warranties typically guarantee 80% output at year 25. But if your panels degrade to 78%, are you really going to pursue a claim? What's the process — do you pay for independent testing? Does the vendor cover labour to remove, test, and reinstall panels? Who pays for scaffolding access?

Workmanship warranties are even murkier. If your roof starts leaking two years after installation due to improper mounting penetrations, many vendors will fix the mount but not the water damage inside your home. And if the vendor has gone out of business — which happens in this industry — your warranty is worthless.

What to ask:

• What exactly does the workmanship warranty cover, and for how long? Get specific: roof leaks, mount corrosion, wiring failures, panel frame issues.
• If there's a roof leak caused by the installation, do you cover repairs to the interior ceiling and waterproofing? This should be in writing.
• How do I make a warranty claim, and what's the response time? Some vendors require you to troubleshoot with their overseas support line before dispatching a technician.
• What happens if your company is acquired or closes? Are warranties transferred? Is there insurance backing?
• Who handles panel warranty claims — you or the manufacturer? If it's the manufacturer, are they even represented in Singapore?

Why Are You Recommending This System Size?

Here's an uncomfortable truth: some vendors size systems based on what fits on your roof, not what matches your actual consumption. A bigger system means a bigger sale, even if half the energy you generate goes to export at a lower tariff rate than you're saving on consumption offset.

We always start with the client's electricity bills and usage patterns. If you're exporting 40% of your generation because everyone's out during peak sun hours, the payback period stretches — or vanishes entirely, depending on export rates. A smaller, optimally sized system often makes more financial sense.

What to ask:

• Did you review my actual electricity consumption before recommending this system size? If they didn't ask for your bills, they're guessing.
• What percentage of my generation do you expect I'll consume versus export? Ask for a breakdown based on your usage profile.
• What's the payback period if export rates drop or disappear? SP's export rates aren't guaranteed forever. Stress-test the financial model.
• Would a smaller system with battery storage give me better ROI? Batteries are expensive today, but if your goal is resilience or maximising self-consumption, it's worth discussing.

What Happens If I Sell the House?

Solar systems can add value to a property, but only if they're properly documented, transferable, and not a legal or maintenance liability. We've had buyers walk away from landed properties because the solar installation had no BCA approval, or because the seller couldn't provide warranty documentation or O&M manuals.

If you're financing the system with a loan, there may be complications transferring that obligation. If the system is leased (rare in Singapore but it exists), the new owner has to agree to take over the lease or you pay out the remainder.

What to ask:

• Will I receive all permits, approvals, warranties, and as-built drawings in a transferable format? You need a clean handover package for future buyers.
• If I sell the house, can the new owner assume the warranty? Some warranties are non-transferable.
• Is there any financing or leasing structure that would complicate a sale? Clarify upfront if you're considering payment plans.

Frequently Asked Questions

Do I need to upgrade my roof before installing solar panels?

It depends on your roof's age, design, and load capacity. We always conduct a structural assessment first. If your roof was built before 2000 or uses lightweight timber trusses, there's a decent chance you'll need reinforcement — which we handle in-house as part of the job. A reputable vendor won't guess at this; they'll verify with drawings or a site inspection before quoting.

What happens if my inverter breaks after the warranty expires?

You'll need to replace it out of pocket, which typically costs $2,000-$5,000 depending on system size. This is why we always discuss inverter lifespan upfront — it's a real cost that should be factored into your payback calculation. Some vendors offer extended warranties or maintenance contracts that include inverter replacement; compare the lifecycle cost, not just the upfront price.

Can I install solar without BCA approval?

No. Any structural addition to your roof, including solar mounting systems, requires BCA submission and approval. We've seen homeowners get caught by this — usually when they try to sell and the buyer's lawyer asks for permits. Unpermitted work has to be torn down or retroactively approved, which is expensive and often impossible if the system doesn't meet code.

Will solar panels damage my roof or cause leaks?

Not if installed correctly. The risk comes from improper mounting — penetrations that aren't properly flashed, over-torqued bolts that crack tiles, or ballast systems that overload the structure. This is why we ask who's doing the structural work and whether roof waterproofing is included in the scope. If a vendor won't guarantee leak repairs caused by their installation, that's a red flag.

How do I know if a solar vendor is reliable?

Check their BCA contractor license, ask for references from landed projects (not just commercial), and verify that they have in-house or contracted QPs for submissions. Ask to see a sample contract and warranty document before you commit. If they can't answer the questions in this article clearly and in writing, keep looking. We've been doing this for 15 years — the serious vendors aren't afraid of detailed questions.

We've installed solar on dozens of landed properties, and the projects that go smoothly are the ones where we ask the hard questions upfront — about loads, permits, lifecycle costs, and what happens when things go wrong. If you're considering solar and want a builder's perspective, not a sales pitch, reach out to us on WhatsApp. We'll tell you what your roof can handle and what the real costs look like over 20 years.