Signs Your Commercial Building Is Suitable & Ready for Solar
Not every commercial building is a great fit for solar, many must undergo renovations and adjustments before they can support solar infrastructure. That's something worth knowing before you start a project.
This isn't a substitute for a professional site assessment. Roof structure, electrical capacity, and shading all need an expert assessment to confirm. VCT Group offers free site assessments across Ontario.
Think of this as a practical starting point for evaluating whether your building could be a strong candidate before you commit.
Your Roof Has Enough Usable Space for Commercial Solar
System size depends on how much usable roof space you have. As a rough guide, flat commercial roofs need about 100 square feet per kilowatt of solar capacity, although this varies by panel and layout.
Not all roof space is usable. HVAC units, skylights, vents, fire setbacks, and walkways can significantly reduce the area available for panels.
A quick self-check is to look at your roof or satellite imagery and estimate how much open, unobstructed space remains. If there's less space than expected, solar may still be an option, but the system may need to be smaller or another structure type may make more sense.
We always advise those interested in solar to reach out during the design stages of a building so we can provide insight into the best layout for roof space without making any sacrifices to utilities or solar.
Your Roof Can Support a Solar System
Roof age matters less than how much useful life it has left. Solar panels can last 25 to 30 years, so it's generally best to have the same amount of remaining roof life before installation. Otherwise, you may have to remove and reinstall the system when the roof needs replacement.
A professional inspection is needed to confirm the roof's condition and structural capacity. VCT Group's free site assessment looks at these factors directly rather than relying on roof age alone.
The important takeaway from this: If the roof isn't suitable, that doesn't mean you can’t go solar. Ground-mounted systems and solar carports are great alternatives that don’t involve any roof replacements or modifications.
Your Building Gets Enough Sun Exposure and Orientation for Solar
Orientation and shading affect how much a solar system will produce.
South-facing roofs with minimal shading throughout the day are the traditional choice, though east-west orientations can also work well depending on the site and how a system is designed around it. Trees, adjacent buildings, and rooftop equipment casting shadows across panel arrays all reduce output, sometimes more significantly than building owners expect.
The ideal site has consistent, unobstructed sunlight for most of the day. If your roof does not, a solar carport over a parking area can sometimes solve both the space and shading issues, since it is a separate structure.
Your Electrical Service Has Capacity for Solar Interconnection
Before a solar system can be connected, your local utility needs to confirm there's enough capacity on the distribution system to accept it, a step VCT Grouphandles directly as part of the interconnection process through what's called a Connection Impact Assessment.
This isn't something you can fully self-check, but it's worth knowing upfront: an older or fully utilized electrical service doesn't automatically rule out solar. It may simply mean additional utility coordination is needed for the project.
Your Energy Usage Pattern Matches What Solar Can Offset
Solar works best when your building's electricity consumption overlaps with when panels are actually producing, which is during daylight hours. A business with a lot of daytime electricity use (manufacturing operations, retail locations, offices during business hours) tends to see stronger self-consumption.
This matters for Ontario businesses because of how net metering credits are structured. In net metering, exported surplus is credited at full retail value, but only for up to 12 months before unused credits expire. Because of this, usage patterns should, ideally, align with solar production in order to see more consistent value from the system than one that generates a large surplus it can't use before credits reset.
You Have Ownership Clarity or Long-Term Lease Terms
This factor is easy to overlook because it isn't a physical feature of the building, but it can be just as important as roof condition. Solar is a long-term investment, so it's important to know who can approve the project, who pays for it, and who benefits from the energy savings.
On leased properties, this can create a "split incentive." The building owner may pay for the solar system while the tenant benefits from lower electricity costs. Solar can still work on leased properties, but clear agreements between the owner and tenant make the project much easier to move forward.
If you're considering solar for a multi-tenant property, it's worth considering this before the project gets to the design stage.
What Happens If Your Building Isn't a Fit Yet
Just because your site doesn’t fit all of the criteria above doesn’t mean it’s the end of your solar journey. A roof with a few years of life left, a shaded rooftop, or a service with limited spare capacity are all things a proper site assessment identifies early, before money gets spent on a system that isn't the right fit.
There are alternatives that can work around a building's specific limitations. Solar carports, for example, avoid roof condition and shading issues by using an independent structure over a parking area. (VCT Group's Heliostation™ carport at Pickering Casino Resort is one example of this approach at commercial scale).
Ground-mounted systems can be a good option when a roof doesn't have enough usable space. The goal of an assessment isn't to make solar work regardless of the site conditions. It's to determine which approach makes the most sense for your property.