Earning potential
Your earning potential on this plumber role
Typical: 3–4 per day
Typical client spend: £250–£350
Up to 50% of every job value
Per job
£90
Per day
£360
Per week (5 days)
£1,800
Per year (~232 days)
£83,520
Estimated earning potential based on typical UK job volumes and fee levels — not a guarantee. Actual earnings depend on work flow, ticket size, and hours worked.
About the role
Window Fitter — Sheffield and South Yorkshire. Self-employed profit-share role, not a wage. You keep 30% of every job KJ Windows routes to you. We survey, price and order the frames; you receive a fitting slot with confirmed measurements and delivery. You'll be sent to uPVC and aluminium window replacements, French/patio and composite door installs, trickle-vent retrofits, sealed-unit swaps on failed glazing, and minor plaster/make-good finishes. Typical job is a house-full fit over 1–2 days, or a single-frame swap in a couple of hours. Jobs are dispatched via the KJ portal with the survey sheet, frame schedule, glass spec and access notes confirmed. FENSA/CERTASS certification is handled through the KJ scheme registration — you don't need to be individually registered. Tickets range from £250 for a single sealed-unit swap up to £6,000+ for a house-full, so the calculator above shows what a booked week on 30% share clears. Suits an experienced window fitter with own tools and van.
Responsibilities
- Remove existing frames cleanly with minimal make-good damage
- Install new uPVC / aluminium frames level, square and plumb, foam and mechanically fixed to spec
- Fit sealed units, hardware, restrictors and trickle vents where scoped
- Seal externally and internally to weather-tight standard
- Make good internal reveals and sills (plaster patch, silicone finish)
- Fit composite / uPVC entrance and patio doors
- Photo-document each frame in the KJ portal for FENSA compliance
- Leave the property clean and dispose of old frames per the job scope
Requirements
- Time-served window fitter
- Own van and full window-fitting toolkit
- Full UK driving licence and right to work in the UK
- Public liability insurance
- Smartphone for the KJ portal
- Customer-facing manner — you're representing KJ in occupied homes
How working with KJ actually works
From apply to first paid job — four honest steps
- 1
Apply in 60 secs
One tap on this page. No CV wall, no cover letter. Just your name, trade and coverage area.
- 2
Sign your KJ contract
Plain-English self-employed profit-share agreement — 25–50% of job value depending on the role. E-signed. No tie-in, no exclusivity trap.
- 3
Log in to the KJ Portal
See the jobs allocated to you: address, scope, customer notes, agreed price. Accept the ones you want, decline the ones you don't.
- 4
Do the work, get paid your share
Complete the job, mark it done in the portal. KJ invoices the customer. Your share lands on the regular payment cycle — no chasing, no unpaid quotes.
The KJ Portal is rolling out through 2026 — until then, early hires are onboarded and dispatched directly by the KJ ops team. Same profit-share, same transparency.
Why KJ, not a company job
A plumber does 3–4 jobs a day; a surveyor 2–4; a solicitor a handful of matters. The client pays hundreds — often thousands. You take home a fraction. The company keeps the rest.