The site survey: what we look at and why

The doorbell. The technician who was coming to look at the roof has arrived. And as you let them in, the usual doubt: is this a real visit or a formality to confirm the price?

Good question. This article explains exactly what we look at during that visit and why each thing matters, so you know what to expect and can judge whether the survey you were given was a serious one.

First things first: if there was no visit, there's no firm quote yet. There's an estimate. It may be well made and useful for starting the conversation, but the final numbers come from what's seen on site. The visit isn't a bureaucratic step: it's where your project stops being generic and becomes yours.

The actual available surface. In the satellite photo the roof is always bigger than in person. Up close, the water tank, the aerial, the flue, the skylight all appear. We measure what's genuinely left for panels.

Shade, with tools. You've already done your at-home look; we do the study with the sun's path across the whole year, using applications that simulate where the shadow falls in each month. August's shadow isn't there in January, and the system has to work all twelve months. The exact position of each panel depends on this, and it's one of the decisions that most affects how much you'll generate.

The material and condition of the covering. Which sheet metal or tile, in what condition, over what structure. We're looking for two things: that the anchoring can be done safely and watertight, with no future leaks, and that the roof has a life ahead of it comparable to the system's. If we see it needs work, we tell you beforehand, even if it delays the sale. Installing over a roof that needs repair means doing the job twice, and you pay for the second time.

The cable route. Where the cables run from the roof down to the distribution board. It looks like a detail and it determines part of the cost and the tidiness of the result: there are clean routes and routes that require building work.

This is the part of the visit nobody expects, and it's among the most important.

The state of your electrical installation. The solar system connects to your board, and the board has to be fit to receive it: adequate protections, a working earth, capacity for the new circuit. In houses with old installations, the survey sometimes finds that the board has to be brought up to standard before connecting anything. That isn't an invented "extra": it's the difference between a safe installation and a time bomb. We'd rather lose a sale by saying it than win one by keeping quiet.

The meter and the connection. Single-phase or three-phase, contracted capacity, where the meter sits. Part of the equipment and of the utility paperwork depends on this.

Besides looking, we ask. And every question has its reason:

• How do you use energy during the day? Determines how much is used directly and how much is fed to the grid.
• Future plans? Air conditioning, a pool, an electric car. They change the sizing, or which doors we leave open.
• Are there outages in the area? How long do they last? Determines whether the conversation includes batteries.
• Who's in the house and when? It isn't nosiness: it's your consumption curve told in human language.

• Did they get onto the roof (or survey it with a drone / measurements), or look from the pavement?
• Did they open the distribution board?
• Did they ask about your consumption, your schedule, your plans?
• Are you left with a written proposal about your actual case?

The quick way to gauge a survey: the more that's measured and the more that's asked, the more tailored the proposal turns out. The time spent on your roof shows up later in the result.