Settle the roof before the array
Panels outlast most roof coverings. If yours is within a few years of the end of its life, replace it before the array goes on, because removing and reinstalling a system to reach the roof underneath is a cost with no offsetting benefit at all.
Ask for a condition assessment rather than an age estimate, and consider getting it from a roofer rather than only from the company selling you solar. New England freeze and thaw cycling ages a covering faster than the calendar suggests.
Ask how many layers of covering are present, what the structure underneath is, and whether the framing needs reinforcement to carry the array plus snow load. On older housing those are real questions rather than formalities.
Ask how mounting penetrations are flashed and sealed and what the roofing manufacturer approves for your covering type. Leaks around mounting hardware are the most common physical failure in residential solar, and a climate with snow melt and refreeze is unforgiving.
Find out whether your property is subject to design review
Ask the city early whether your address sits within a historic district or is otherwise subject to review of exterior alterations, and what that process involves. It is a short call and the answer shapes the design rather than following it.
If review applies, treat it as an input to the layout rather than a rubber stamp on a finished one. Approaching design review after equipment has been ordered around a specific plan is how projects end up redesigned.
Ask what the review calendar looks like and whether there are application deadlines, since a body that meets monthly sets the rhythm of your project rather than your installer's schedule.
Ask your installer whether they have taken a project through review in this city before, and agree in writing who is responsible for that filing alongside the building permit.
The incentive, and what has to be in place to receive it
The SMART program is provided to customers of Eversource, National Grid and Unitil, and customers of municipal light plants are not eligible. Confirm which supplies your address before applying any published figures.
For residential systems under 25 kW, SMART payments last for a fixed term of 10 years at a rate determined when you enrol and locked for the duration. Ask what the current residential rate is and get it in writing.
Payments are made directly by the utility via the same billing structure as net metering, and each month the utility reads the production meter and pays the difference between the SMART rate and the value already credited through net metering.
So confirm a production meter is included and reporting, and ask how you can verify that months later. On a constrained older roof the system may be modest, which makes every part of the entitlement worth protecting.
Three state benefits, and the federal one that ended
Massachusetts has a state income tax credit of its own. Under 830 CMR 62.6.1 an owner or tenant of a residential property who occupies it as their principal residence is allowed a solar and wind energy credit against personal income tax equal to fifteen percent of the net expenditure for renewable energy source property, or $1,000, whichever is less. It is claimed on Schedule EC.
Note that it is available to a tenant as well as an owner, which is unusual and worth knowing if you are paying for a system on a property you occupy but do not own. Ask a tax advisor how it applies to your circumstances, since a credit is only worth what you can use against tax owed.
There is also a property tax exemption of 100 percent for 20 years for solar installations, and equipment for a solar system used as a primary or auxiliary energy source in a principal residence is exempt from sales and use tax. Neither arrives as a cheque, which is exactly why both get left out of people's own arithmetic.
On the federal side, the 30 percent Residential Clean Energy Credit under Section 25D expired for property placed in service after December 31, 2025, so a cash or loan purchase now receives no federal credit. Section 48E survives at 30 percent for third-party owners under leases and power purchase agreements, so ask any such provider what they claim and what of that value reaches you, and confirm with a tax advisor.