Site Survey — Avoid Solar Surprises

Site Survey stone-coated steel roof


As good as today’s solar design tools are, they’re no substitute for getting a site survey up close.

The solar industry invented many semi-automated computer programs that start with your address and your geographical location. Using satellite photos, data from your Utility, historical weather patterns, and local solar production data, we can calculate the system you need from a distance. However, making sure you can attach the system to your house, is still a good idea which requires surveying the structure up close.

Site Survey stone-coated steel roof
Site survey view of a stone-coated steel roof in Martinez

Software is a great aide, very fast and consistently more accurate with the math calculations. However, I prefer my solar partners to employ a human being to conduct a site survey, looking for things hidden from the computer’s view.

What is a site survey?

A site survey is consists of a short physical inspection of a specific home’s suitability for residential solar. A qualified solar pro visits the house looking for anything that is relevant to the project’s success. We do this in order to prevent or prepare for potential surprises during installation of the solar equipment.

Site survey view of roof from attic
Solar site survey of roof structure–this one has skip sheathing

The site surveyor looks for conditions that can’t be seen from a satellite photo. These can include the health and safety of the main electrical panel, as well as its capacity for solar equipment. He or she may peek in the attic looking at the structure and condition of the roof.

Is the roof in good shape? If it is already leaking, or near the end of its useful life, we might call for a re-roof, first. Does an attic or vaulted ceilings require a different method of attachment? Is there room to mount equipment next to the electric meter? Those are just some of the questions a site surveyor asks as part of the survey.

The site survey also provides the design engineer with more data to ensure the system functions, as desired, after install. For example, a recent tree-removal, not shown in satellite view, would affect system production.

The site surveyor will usually measure the sunlight using a device that extrapolates where the shade is at other times. It helps confirm data from the satellite view.

TIP FOR HOME BUYERS AND AGENTS: Read this and other posts about installation, if may want to add solar later. Consider consulting someone like me, before you submit an offer on a home. While most issues have workarounds, some do not.

Solar Site Survey Objectives

Site Surveyor electrical panel and electric meter
Site Surveyor checking the main electrical panel capacity

I thought about calling this post, “Site Survey — Avoid Solar Problems,” but realized it wasn’t appropriate. Getting electricity in any form is a problem, if for no other reason than a custom fit requires many calculations.

We decide to go solar to solve problems, in the first place.

That said, some solar problems should definitely be avoided, not solved. Others should be solved easily, not the hard way. Much of this depends on order and timing.

In the scheme of things, the actual installation of solar is a simple construction project. Solar pros with experience and preparation, usually complete the job in a matter of hours.

Use your site survey to maximize the chances that the install team has with them on installation day, the equipment and skills they need. A site survey will minimize use of change-orders, delays, or added costs.

They should prepare for significant construction challenges specific to a particular install before there is a crew on the roof.

If conditions warrant changes, the solar company can then consult the homeowner and explain the options. If necessary, they will adjust the agreement and design before spending significant time and money.

Completion of the site survey is also the homeowner’s last best chance to make any design and location adjustments. Usually, the designer finalizes the design upon getting the data from the site survey, and submits it for approval, immediately. So, make sure you give the project manager and design team everything needed to meet your expectations. This might include the layout of the solar modules/panels and placement of batteries, for example.

Later changes can delay the completion of your project, or increase the costs–though this may still possible to do right up until the day of install.

Communication and Teamwork

Each solar team you work with has their own way of organizing. Teams can include independent contractors, employees, and multiple specialists. They may also have partnerships with multiple entities (financing, installation, sales/customer service, manufacturer). Not to mention local building inspectors and the Utility. It’s therefore important to pay attention to text messages, calls, and/or e-mails.

If you get a request for information or are asked to confirm an appointment time, don’t delay your response.

Because we are working with specialists, the site-surveyor may relay information to a designer you don’t meet. You’ll probably meet the site-surveyor, once. (That’s too bad, because I’ve met a few, and they were likeable and helpful.)

By all means, ask them to relay any concern you have, but if you’ve been given a project manger or other contact, follow up with them, too.

An often very busy project manager usually handles communication among the install team. A well-organized solar team is going to give you contact information just for the installation, so pay attention. Communicate directly with someone in a position to respond to your needs.

By the time the team is on the roof, they are often just following instructions, and you may need to reach out to someone above them. That’s another reason not to wait if you have any concerns or questions.

Site survey photo of main electrical panel
Site Survey photo of inside the main electrical panel

Starting on the Right Foot

Some installers require a deposit or down payment before sending a site surveyor, because with travel time, it is an expense to the company. But, the installers I’ve worked with, simply require a signed agreement.

We assume we can accommodate small changes at no extra charge. If we can’t, we’ll revisit the agreement at that time.

Schedule a site survey as soon as possible after you agree, to assure yourself your home really is suitable for solar.

What? No Site Survey?

Amazingly, many installers simply wing it, skip the in-person site survey or send a beginner. This can mean they miss surprises. Often, these may be hidden in the attic. For example, they plan to run conduit through the attic, but there isn’t one. Or, perhaps, it’s a tar and gravel roof and they brought hardware for composition shingle roof. Now the skilled electrician or the team on the roof has to wait for materials or come back another day.

A Site Survey is Worthwhile

Make sure your solar provider schedules your site survey as soon as possible. Predicting the weather is hard enough, without adding other unknowns. Then, keep the site survey appointment, or the remainder of the job will slip.

REMINDER: After the site survey the design is finalized and submitted for permits. Be sure to review these documents for changes to the location and appearance of your solar equipment, in addition to changes made for other reasons.

For more details on what a solar site survey involves, see my blog post called “Solar Suitable? or, Attic Parkour.

If you have solar modules already, are there any things you wish you had done differently? What surprised you? Please comment below, and Bookmark, Like, Share, Follow, or Subscribe. Contact me with questions or suggestions.

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