Solar Panel Quotes: Fixed Price vs Day Rate in 2026 (UK)
A fixed-price solar quote names one all-in figure for the finished system; a day-rate quote charges labour per day plus materials at cost. For a standard 4–6kW roof install in 2026, fixed price is the safer default — the installer carries the overrun risk and you know your number before scaffold goes up. Day-rate can come in cheaper on simple, predictable roofs, but a single complication (hidden rafters, a re-route, an extra string) lands on your bill, not theirs. Here is how each model works, when each wins, and the clauses to insist on either way.
Fixed price vs day rate at a glance
| Factor | Fixed price (turnkey) | Day rate + materials |
|---|---|---|
| Who carries overrun risk | The installer | You |
| Price certainty before start | Total known up front | Estimate only |
| Typical 4–6kW figure (2026) | £5,500–£9,000 all-in | £450–£650/day labour + materials at cost |
| Best for | Standard roofs, batteries, EPC works | Simple, predictable single-string roofs |
| Change handling | Variation order, agreed in writing | Added to the running tally |
How a fixed-price solar quote works
A turnkey fixed price wraps panels, inverter, mounting, DC/AC cabling, scaffold, MCS certification, DNO notification and commissioning into one figure. A reputable installer surveys the roof, models the array in software, and prices the known scope. Because they own the overrun risk, they build in a contingency — which is exactly why fixed price can look a little higher line-for-line but rarely moves once signed.
How a day-rate solar quote works
Day-rate splits labour (a crew day rate, typically £450–£650 for two installers in 2026) from materials supplied at or near trade cost. On a clean two-day install this can undercut a fixed price by 10–15%. The catch: if the roof hides a cracked tile batten, the run needs re-routing, or the DNO requires an export limiter, those hours and parts are added to your bill.
When each model wins
Choose fixed price when…
The job includes a battery, an EPC-driven upgrade, a non-standard roof (slate, clay, hipped, multiple pitches), or you simply want a single number to compare across installers. It is the safer default for the vast majority of UK homeowners.
Choose day rate when…
You have a simple, modern interlocking-tile roof, a single MPPT string, an experienced installer you trust, and you are comfortable absorbing a modest overrun. On the right job it is the cheaper route.
Contract clauses to insist on either way
- Written scope and exclusions — exactly what is and isn't included (scaffold, making good, bird-proofing).
- Variation procedure — any extra agreed and priced in writing before work proceeds.
- MCS certificate & DNO sign-off — both delivered before final payment.
- Payment milestones — modest deposit, balance on commissioning. Avoid large up-front payments.
FAQs
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