No fee on a house, and a three day target
A building permit is required for all solar installations in Elgin, and for solar on a single-family or two-family residential structure there is no permit fee and no plan review fee. The city aims to respond to a solar permit application within three business days or less.
Other structures are charged: $70 per 1,000 square feet of panels plus a $75 plan review fee. That distinction matters if the building you are thinking about is not a house or a two-family property, because the fee then scales with the size of the array rather than being waived.
A three business day target is a response time on a submitted application, so a complete package is what gets you the benefit of it. Ask your contractor what the submission needs to contain and whether they file it themselves. Ask as well who books the inspection, since the most common cause of a stalled project is each party assuming the other was handling the next step.
How ComEd credits exported power now
As of 2025, new residential and small commercial net metering customers in ComEd territory moved from full retail rate net metering to supply-only net metering, which credits the electricity supply portion of the bill rather than the full retail rate.
The gap between the two is the whole design argument. A kilowatt-hour you use at the moment you generate it avoids the full retail price, supply and delivery both. A kilowatt-hour you export earns the supply-only credit. Nothing about the panel changes, only what the household does with the output, so a system matched to your own consumption returns more per dollar than one built to fill the roof.
Illinois net metering has been through ongoing Illinois Commerce Commission proceedings and terms can shift again, so ask your installer to confirm the current tariff for your address at quote time. Treat undated guidance carefully, because a great deal of what is online still describes the pre-2025 arrangement.
Roofs here, including the townhouse question
Single-detached houses are 61.9 percent of Elgin's 40,523 housing units, so most residents control the roof and the decision outright.
Single-attached townhouse-style units are 13.9 percent, a large enough share to be worth addressing directly. A shared wall does not necessarily mean a shared roof, and the first job is establishing what you actually own and where the boundary runs. That is a survey question, sometimes a title question, and it is cheaper to answer before a design is commissioned than after.
Two-unit buildings hold 4.4 percent and three and four unit buildings 4.9 percent, where an array feeds one electrical service and therefore reduces one household's bill rather than splitting between them. Buildings of 20 or more units hold 4.8 percent, where the roof belongs to the owner or the association rather than a resident.
About 1,261 kWh a year for every kW
Use roughly 1,261 kWh a year per kW installed as the planning figure. It is derived from satellite irradiance data with a standard performance ratio applied rather than measured on local roofs, so it is the number for deciding whether to get quotes rather than the number to hold anyone to.
Orientation sets the daily shape of production, pitch affects yield and how quickly snow clears, shade decides how much of the theoretical output you keep, and usable area shrinks once vents, stacks, chimneys and setbacks are subtracted. Winter shading deserves a specific question, because a low December sun reaches under tree canopy that clears the roof easily in July.
Ask for the model broken out per roof plane with the shading assumptions stated. Two proposals with the same annual total can be quite different systems, one where every panel sits on a good plane and one where a third of them are filling space.
What money is actually available
Illinois Shines, the state Adjustable Block Program administered by the Illinois Power Agency, pays Renewable Energy Credit money to Approved Vendors under its Distributed Generation track, and vendors may pass that value on as reduced equipment or installation cost. Participation requires an Approved Vendor. Because the pass-through is a commercial decision rather than a published rate, ask every vendor for their Disclosure Form showing exactly how much of the REC payment reaches you.
Illinois Solar for All is the separate income-based program, covering homeowners, renters through community solar and multifamily building owners, on terms designed so participating households pay less for electricity than they would have without solar. Eligibility is income-based and worth checking before you shop rather than after.
The 30 percent federal residential tax credit under Section 25D applied through December 31, 2025 and is not available for a purchased home system placed in service after that date, so a 2026 purchase in Elgin cannot claim it. A lease or power purchase agreement provider may claim the separate business credit under Section 48E and reflect part of it in the rate they quote, which is a question for the provider and a tax advisor rather than an assumption.