UK rooftop PV
Is that roof worth pursuing? Yield, payback, engineering flags, and a board-ready verdict — before you spend a pound on surveys.
The installer's study is free because they earn nothing from a no.
No card needed · Verdict within 3 working days
Paid the same for a yes or a no
We do not design, install, or sell equipment, and we hold no referral or revenue relationship with anyone who does. Our fee is the same whether the verdict is pursue or park — so the numbers reflect your roof and load, not someone else's margin.
Once we reach ten completed assessments, we will publish the proportion we recommended against. If we ever accept a referral fee, this page will say so.
Assessments are feasibility screenings for investment decisions — not design or construction documents.
Written verdict
Pursue or park
board-ready recommendation
Defensible returns
25
years of payback & NPV modelled
Right-sized system
Your roof & load
not maximised for installer margin
Risks before spend
4
engineering flags with next steps
The problem
Every large roof looks like a solar opportunity, and some are. The usual way to find out — surveys, installer visits, quotes written to sell, or slow early consultancy with opaque workings — costs real money before anyone has tested whether the numbers hold. Stage1Energy runs that test first: a fixed-fee, fully sourced dossier, reviewed before release, delivered in days.
What you get
Four things every dossier answers — each one in the worked example on the assessment page.
Financial case
Simple payback and 25-year returns, modelled for your roof — not a salesman's estimate.
The verdict
A clear pursue-or-park recommendation with system size, yield, and NPV — language a board can read.
Engineering
Four engineering screening flags — wind, structure, DNO, planning — with next steps for each.
25-year model
Cumulative cashflow, monthly generation, and self-consumption — hour by hour, not assumed.
Free screening vs full assessment
Both run on your building. The free screening tells you whether to pursue. The full assessment is the board-ready dossier — financials, scenario optimisation, engineering flags, and fully sourced workings.
The free screening answers “is this roof worth a closer look?” The full assessment answers “can I put this in front of the board?”
Inside every dossier
Capex on day one. Break-even in the first years. Two decades of return after it. Every dossier models this curve for your building — hour-by-hour yield, degradation, and energy prices included. See a real one.
Who it serves
Same dossier. Same care. Landlords, estates teams, developers, and advisers — anyone who needs a written pursue-or-park answer before survey spend. One free screening or rolling portfolio assessments: the standard does not change with scale. Large portfolios of 80+ roofs run as a programme — sequenced and priced by enquiry. Assessing several roofs? See the portfolio programme.
What it costs
Start here
Free
One building · 3 working days
A plain pursue-or-park verdict, panel placement, and monthly generation. No card needed.
No card needed
Recommended
£1,250
Per site · 5 working days
The board-ready 29-page dossier: 25-year cashflow, four engineering flags, and sourced workings — reviewed before release.
80+ roofs
£250k+
No ceiling — priced to the size of your estate
From £1,250 per site · priced per programme by enquiry
Same dossier for every building, plus a cross-portfolio ranking that shows which roofs to pursue first. Programmes from a handful of sites to 80+ — no hard ceiling on portfolio size.
Or screen one building free first
A structural survey on a roof that was never viable costs £2,000–£5,000. The remote, evidence-based feasibility assessment that tells you whether the survey is worth commissioning is £1,250.
Clear go or no-go with the evidence to defend it — or we rework the dossier at no extra cost. Written into the terms of engagement.
Need it faster? Priority delivery in 2 working days is £1,750. Same document, either way.
One site or a portfolio — the same standard at any scale. Large programmes (including 80+) are sequenced and priced by enquiry. See pricing detail.
The guarantee
That's the whole guarantee. It's written into the terms of engagement.
Company
Stage1Energy Ltd · Co. 17222440
Fee
Fixed per site · written terms before work starts
Care
Every dossier reviewed before release — one site or many
Scope
Feasibility, not design · built from satellite and metered data, validated against twelve months of metered output from an operating commercial installation
Popular guides
Process & comparisons
Financial
Process & comparisons
Process & comparisons
Financial
Financial
Process & comparisons
Guide
Questions
A screening on your building: a clear verdict, panel placement on your roof, and a monthly generation profile. Delivered within 3 working days. No card needed. Not the full dossier — no financial model, scenario optimisation, engineering flags, or sourced calculation workings.
29 pages: a written pursue-or-park verdict, the full financial case with a 25-year cashflow model, zone-by-zone roof layout, four engineering screening flags (wind, structure, DNO, planning) with next steps, and fully sourced calculation workings. Reviewed before release.
From £1,250 per site, delivered in 5 working days. Priority delivery in 2 working days is £1,750. Same document either way. Fixed fee, written terms. One site or a portfolio — the same standard at any scale. Large programmes (including 80+) are sequenced and priced by enquiry.
You'll get a clear go or no-go with the evidence to defend it. If a delivered dossier doesn't give you that, we rework it at no extra cost.
Start here
Pin the roof and get a verdict in writing — or explore the worked example first.
No card needed · A verdict within 3 working days
