Home Solar Pre-Signing Checklist
A step-by-step checklist that walks a homeowner from the utility data and roof survey through panel, inverter, and battery choices, the savings assumptions, the installer, and the contract, so nothing important is left to trust on signing day.
Reviewed for 2026, updated September 8, 2026.
Most disappointing solar systems were not sold with a lie. They were sold with an omission: a shade study nobody took from the roof, an export rule nobody confirmed with the utility, a savings projection whose assumptions nobody wrote down, or a workmanship warranty nobody read. Each of those gaps is easy to close before signing and expensive to close afterward, once the array is bolted to the rafters and the crew has driven away. This checklist gathers the confirmations we would want in hand before committing to a system that will sit on the roof for a quarter century. It follows the order of our guide at /guide/, from the household and the roof through equipment, storage, economics, the installer, and the contract, and every line is something you can verify yourself or ask a named person to put in writing.
Work through it in two passes. The first pass, before you request quotes, covers the data you should bring to the table: bills, interval data, future loads, roof condition, and the export rule. The second pass runs against each proposal you receive. Three tools on this site do the arithmetic for several lines: the Solar Array Size and Panel Count Estimator at /tools/solar-array-size-estimator/ gives you an independent size to hold against the quote, the Home Battery Backup Sizing Calculator at /tools/battery-backup-sizing/ turns a list of circuits into a capacity and power figure, and the Home Solar Payback and Lifetime Savings Calculator at /tools/solar-payback-savings/ lets you re-run the projection with your own assumptions. For the reasoning behind the quote lines, read /blog/compare-home-solar-quotes/ and /blog/two-solar-quotes-one/. Solarholm is independent, we install nothing, and if you finish this list and decide to wait a year, that is a perfectly good outcome.
- Twelve months of utility bills gathered, with monthly kWh and, where the utility offers it, hourly interval data downloaded so seasonal and time-of-day patterns are visible.
- Future loads written down before anyone talks about size: an electric vehicle, a heat pump, a pool pump, or an addition planned within the next several years.
- Roof age and remaining life assessed by a roofer, with a decision made on reroofing before the array goes up rather than paying to remove and reinstall it later.
- Shade analysis taken from the roof itself, not from satellite imagery alone, covering morning, midday, and afternoon shadows across the seasons.
- Utility export rule confirmed in writing: full retail net metering, net billing at a lower export rate, or time-of-use pricing, since this drives both sizing and the battery case.
- Target system size checked against your own estimate rather than accepted from the proposal, with a reason given for every panel beyond your self-consumption threshold.
- Panel datasheet reviewed for temperature coefficient, the degradation guarantee, low-light behavior, and mechanical load ratings, not just nameplate wattage.
- Cell manufacturer and the company standing behind the panel warranty identified, with an honest view on whether it is likely to still exist in year twenty.
- Inverter architecture chosen on purpose, plain string, string with optimizers, or microinverters, matched to your shading and to any plan for a battery.
- Panel-level monitoring confirmed if the roof has any shading or if you want to be able to spot a single failing module years from now.
- Battery purpose stated plainly, backup, daily energy management, or both, before any capacity figure is discussed or priced.
- For backup, the circuits to keep alive listed and agreed, with a critical loads panel or whole-home gateway specified and large motor loads such as central air addressed.
- Battery specifications compared on usable capacity, continuous and peak power, round-trip efficiency, chemistry, and the throughput or cycle limit written into the warranty.
- If storage is deferred, the inverter and gateway design confirmed to accept a battery later without replacing the inverter.
- Savings projection assumptions obtained in writing, rate escalation, export compensation, annual degradation, and analysis horizon, then re-run with conservative values.
- Incentive and tax treatment verified with your own tax professional for the current year rather than assumed from older guides or the sales proposal.
- Each quote normalized to price per watt installed and first-year production per watt so proposals of different sizes can be compared on the same footing.
- Installer vetted: years under the current company name, own crews or subcontractors, who holds the electrical license, and how a panel failure in year twelve would be handled.
- Roof penetrations, flashing method, conduit routing, and the view from the street discussed and, where it matters to you, drawn on the plan set.
- Product, performance, and workmanship warranties read in full, with the workmanship term and the remedy for roof leaks at penetrations written into the contract.
- Contract checked for a production guarantee with a clear remedy, a milestone timeline, and clarity on who handles permits, inspection, and utility interconnection.
- A plan written for what happens if the utility rejects the interconnection application or the local authority requires design changes after signing.
- Monitoring access, transferable warranties, and a full documentation package, plan set, datasheets, permits, and production history, required as deliverables at handover.
https://solarholm.com/templates/home-solar-pre-signing-checklist/Use it in your business, share it with your team, or link to it from your own site.
Also from Solarholm
- Solar Quote Comparison Worksheet: A side-by-side sheet that brings up to three solar and battery proposals down to the same metrics, size, price per watt, production per watt, savings assumptions, warranties, installer, and contract terms, so the spread between them finally makes sense.
- Free calculators