Before any Bali villa solar project makes sense on paper, someone needs to stand on your roof, look at your PLN meter, and count the trees casting shade across your panels. That's the survey, and it's the step that separates a well-sized system from a disappointment six months after commissioning.
Most problems we see after install trace back to a survey that was too shallow. A quote built on satellite photos and a brief WhatsApp exchange might be fast, but it misses the roof leak risk hiding under a cracked terracotta tile, the banyan tree shading half your panels every afternoon, or the single-phase PLN connection that limits your inverter options. This checklist covers what a credible surveyor should check, so you know what to expect and can hold your installer to it.
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TL;DR
- A real on-site survey covers at least seven areas: roof structure and condition, panel orientation and tilt, shading analysis, load profile, PLN connection details, site access, and local heritage or permit rules.
- Terracotta tile roofs need a load-bearing check before adding panels. Old timber joists in 1980s to 1990s Bali villas may need reinforcement before supporting 15 to 25 kg per sqm of panels and mounts.
- Shading is the most commonly skipped survey step. A proper audit visits your villa at multiple times of day, ideally during wet season when tropical canopy is densest.
- Your PLN connection matters: 1-phase vs 3-phase, VA rating, and breaker condition all affect which inverter fits and what the system can do. The surveyor should inspect your meter panel, not just note the address.
- A quote without an on-site survey is a yellow flag. Photos and drone footage don't replace standing on the roof and checking the PLN board in person.
- Heritage and banjar rules in areas like Ubud can restrict visible rooftop modifications. Your installer should confirm this before you sign, not after permits are denied.
What a real survey covers
A good survey takes two to four hours for a typical Bali villa. The surveyor walks the roof, measures usable panel area, checks the structure, inspects the PLN meter and breaker board, does a shading analysis, and talks through how you actually use power.
Some installers skip parts of this. A surveyor who spends 30 minutes, takes five photos, and sends a quote the same day has probably guessed at critical details. The seven areas below are the minimum you should expect covered before you see a quote.
Roof structure and panel orientation
Roof material and condition. Three roof types dominate Bali villas, and each has different implications for how panels are mounted and sealed.
Terracotta tile is the most common finish on older villas. Tiles need to be checked individually for cracks, slippage, and missing pieces before mounting. Installation requires tile-specific brackets and professional flashing at every penetration point. A surveyor who looks at your terracotta roof and doesn't mention waterproofing is skipping something important. Tile penetrations done poorly are the source of most year-3 roof leaks on solar installs.
Corrugated metal (zincalume or similar) is standard on newer builds and many holiday rentals. Metal roofs are faster to mount on and less leak-prone with clamp-type mounts that don't require tile penetration. The surveyor should still check for rust spots, dents, and loose sheet screws that could shift under panel weight.
Concrete flat roofs (dak) are increasingly common on modern Bali villa designs. Flat-roof panels need a tilt frame angled 8 to 15 degrees toward true north, which adds cost but maximizes output. The surveyor should check drainage channel placement, confirm the dak's load rating, and avoid placing ballast mounts where they'd block runoff.
Load-bearing capacity. Panels plus mounting hardware add 15 to 25 kg per sqm to your roof. For most reinforced concrete dak, that's not a concern. For older timber-joisted terracotta roofs common in 1980s to 1990s Sanur, Ubud, and Denpasar villas, the surveyor should inspect the joist span and condition. If there's any doubt, a structural check before signing is worth the wait.
Orientation and tilt. Bali sits at roughly 8.4 degrees south latitude. Optimal panel tilt is 8 to 12 degrees facing true north. The surveyor should record the roof's actual azimuth and tilt, and give you the production impact if it's not ideal. East or west-facing roofs at a 10-degree tilt still produce 92 to 95% of north-optimal annual output, which is acceptable. A south-facing roof is the one that hurts: 85 to 88% annual yield, and that gap compounds over 25 years.
If the main roof doesn't suit, the surveyor should flag alternatives: a garage rooftop, a kitchen block dak, a carport structure, or ground-mount in the compound if space exists.
Shading audit
Bali villa rooftops have more shade risk than most locations. Three sources show up again and again.
Mature tropical trees. A banyan tree can shade a full roof from a single trunk, and its canopy grows fast in the wet season. Frangipani, flame trees, and coconut palms are common in villa gardens and compound borders. A surveyor who doesn't walk the site at three different times of day is missing how shadow movement changes across your roof through the day. Morning sun angles are low and cast long shadows. Afternoon angles are steep but can still pull shade off a nearby tree across the western edge of your panels.
Neighboring villas. In dense villa areas like Seminyak, Canggu, Kerobokan, and parts of Ubud, a two-story neighbor can cast a shadow across part of your rooftop for morning or late-afternoon hours. You don't see this from satellite photos. It requires standing on the roof.
Rooftop equipment. AC condenser units, water tanks, communication antennas, and solar water heater collectors create small shade patches that affect string inverter output out of proportion to their size. A surveyor notes these and adjusts the panel layout to keep them clear of the shade line.
A proper shading audit uses either a sun-path analysis app or a physical solar pathfinder tool. For villas with significant tree cover around the building, the surveyor should ideally visit during the wet season (November to March) when canopy is at its densest. A dry-season survey on a villa ringed by frangipani trees may miss 15 to 20% additional shading.
If shading cuts more than 20 to 25% of annual production, we typically tell clients the math shifts toward "not worth it" unless trimming the canopy is an option. In some Ubud heritage zones, canopy trimming is restricted by banjar rules. If your installer doesn't raise this, raise it yourself.
Load profile, PLN connection, and site access
Load profile. The surveyor should ask for six months of PLN bills, or your approximate monthly kWh usage if you have it. If you don't have that, they should walk you through your appliances: how many AC units, what PK rating, how many hours a day, whether you have a pool pump, well pump, water heater, washing machine, and anything else that draws consistently. A pool pump running 6 hours a day at 1.5 kW is 9 kWh daily, which changes your sizing conversation significantly. The right question from a surveyor isn't "how many bedrooms?" but "what's your highest-use month, and what's driving it?"
Plans matter too. If you're thinking of adding a bedroom, converting to electric water heating, or buying an EV charger in the next three years, the surveyor should know. Designing for current load only and running out of inverter headroom at year four is a common miss.
PLN connection. Your PLN meter panel is the surveyor's second stop after the roof. They should document:
- VA rating: 2,200, 5,500, 7,700, or 11,000 VA. This caps how much grid power you can draw and constrains inverter size for grid-tied and hybrid systems.
- 1-phase vs 3-phase: Most connections up to 7,700 VA are 1-phase. Above that, 3-phase is typical for Bali villas. Hybrid inverters above roughly 8 kW usually require 3-phase. Getting this wrong means choosing an incompatible inverter.
- Breaker and meter condition: Corroded terminals, tripping breakers, or undersized wiring between the meter and the main panel show up as problems after install. A surveyor who flags these lets you budget for fixes before the solar quote is finalized, not after commissioning.
- Meter location: For any system connecting to PLN (grid-tied or hybrid), the meter needs to be accessible for any interconnection work or future SLO inspection.
Site access. For any villa outside central Bali, access logistics are worth assessing. Can a pickup truck reach within 30 meters of the villa? For some Ubud rice-paddy villas, Uluwatu cliff properties, or remote East Bali sites, the last stretch is a hand-carry across uneven ground. Is there a safe staging area for panels before they go on the roof? For multi-day installs on larger systems, is there secure overnight storage on the compound?
Remote villas in Amed, Munduk, Sidemen, or far East Bali coast typically add one to two days of crew logistics, and the quote should reflect this rather than hide it.
Regulatory and heritage. In some areas, notably central Ubud and certain banjar-managed hamlets across Bali, visible rooftop modifications need explicit banjar approval. This varies by village and isn't always predictable from the outside. An installer who knows the area should flag this before you sign. Missing a banjar approval can delay a project by weeks, or in rare cases force a redesign.
For systems connecting to PLN, the SLO (Sertifikat Laik Operasi) certification requires the system to be accessible for inspection. The surveyor should note whether your meter location and roof access support this process.
When this doesn't fit your villa
A few cases where survey findings typically point away from installing:
- Heavy shading you can't or won't trim. If a banyan tree shades 30% of your usable roof daily and trimming isn't an option, the math usually stops working. We'd rather tell you this before you sign than after your first month of disappointing production numbers.
- Roof structure that needs attention first. Old terracotta roofs with cracked tiles and soft timber joists should be repaired before panels go on. Putting a 20-panel system on a roof that needs replacement in 5 years means paying for removal and reinstall down the road.
- No survey offered before the quote. If an installer quotes you based on your address and a bedroom count, without visiting the site, that's a yellow flag. The resulting quote likely has something wrong: the cable run is too short, the battery room location doesn't work, or the roof orientation is worse than expected.
- Heritage zone restrictions that limit usable area below the practical minimum. Some central Ubud compounds have visible-modification rules that make panel installation effectively unworkable. It's rare, but it happens, and you want to know before you've paid a deposit.
We'd rather tell you up front than design a system that disappoints.
Ready to size your home?
If you've read through this and want to get a proper survey scheduled, the fastest path is a short WhatsApp message. Share your villa location, a rough description of your current PLN bill, and whether you have a pool or other heavy loads. We'll coordinate an on-site survey with our partner technician team, typically within two weeks of confirming.
Frequently asked questions
Most credible installers fold the survey into the project, so there's no upfront charge. If an installer charges a large standalone fee just to visit before quoting, that's unusual for residential work. Some independent consultants do charge Rp 500,000 to 1,500,000 for a standalone assessment, which is fine if you want a second opinion. The survey should be a commitment-free step, not a revenue line.
