A commercial solar feasibility study sits at the front of a sensible rooftop PV process. Before anyone climbs on the roof, before a structural engineer produces calculations, and before an installer prices a system they have not yet designed, feasibility answers a simpler question: is this roof worth pursuing?
Definition
A well-run study pulls generation, self-consumption economics, grid constraints, structural and wind-loading flags, and planning risk into one recommendation - pursue, pursue with conditions, or do not pursue - so decision-makers are not left interpreting spreadsheets alone.
Why feasibility exists as a distinct step
Commercial rooftop solar in the UK rarely fails because the technology does not work. It fails because the business case was never properly tested, because a constraint was discovered too late, or because an optimistic quote was mistaken for independent analysis.
Feasibility closes that gap. It is deliberately earlier and lighter than design, procurement, or construction documentation. The commercial solar feasibility service at Stage1Energy is built around that principle: enough rigour for a pursue, pursue with conditions, or park decision - without paying for work that only makes sense once the case is proven.
Think of it as the equivalent of a pre-planning opinion for a development site. You are not submitting a full planning application; you are testing whether one is likely to succeed.
What a feasibility study typically covers
Scope varies by provider, but a credible commercial rooftop feasibility study should address these areas at screening level.
- Roof resource and layout
Usable area, orientation, pitch, shading, and estimated array capacity based on what the roof can accommodate.
- Generation and consumption
Annual kWh yield plus self-consumption versus export assumptions tied to your load profile.
- Financial outcomes
Payback, NPV, and multi-year cashflow using defensible tariff and cost assumptions.
- Engineering flags
Structure, wind loading, roof condition, access, and mounting - enough to know if a full survey will be contentious.
- Grid and planning
G98 or G99 likelihood, export limits, and permitted development versus planning application.
- Verdict
A written conclusion that a board, investment committee, or client can act on.
For a detailed breakdown, see what is in a solar feasibility report or review our example report.
What a feasibility study is not
Clarity about boundaries prevents expensive misunderstandings.
Not a structural pack
It may flag that a portal frame needs checking, but it does not replace a structural engineer's sign-off.
Not detailed design
Cable routes, protection coordination, and as-built single-line diagrams come later.
Not an installer quote
Quotes assume a viable project and embed commercial incentives. See feasibility vs quote.
Not a performance guarantee
Generation estimates are feasibility-grade. Our methodology explains where uncertainty remains.
When feasibility is the right move
Feasibility pays off when you have candidate roofs and limited time to separate winners from dead ends.
- TriggersNet-zero target with an unconstrained estate list, landlord portfolio review, developer testing a speculative unit, or facilities asked to “look into solar” without survey budget.
- Unsure?Waiting list - a short verdict in three working days.
- Full reportThe site assessment delivers fixed-fee feasibility in five working days with financials, flags, and a board-ready verdict.
How Stage1Energy fits the process
Stage1Energy produces fixed-fee feasibility reports for UK commercial rooftops at join the waiting list, with a written scope and human review before release. The same document works for a single warehouse or a batch of sites assessed in parallel.
The output is designed for internal decision-making: enough depth to justify spend on structural and grid work, not so much detail that you have paid for design before you have decided to proceed.
Bringing it together
Takeaway
A commercial solar feasibility study is the disciplined first step that stops weak projects absorbing budget and lets strong ones move faster with confidence. Insist on independence, transparent assumptions, explicit limits, and a verdict you can put in front of a board without rewriting it.
How feasibility fits UK building types
The same framework applies across warehouses, factories, retail sheds, and offices, but the emphasis shifts. A logistics depot leans on high daytime load and large unobstructed roof. A multi-let office may hinge on landlord consent and tenant electricity arrangements. A manufacturing site with shift patterns outside daylight hours needs honest load profiling.
Good feasibility adjusts narrative emphasis without changing core methodology - ending with the same clear verdict structure whether the roof is in Manchester or Cardiff, owner-occupied or landlord-held.