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Rooflight Installation Cost Calculator

Estimate UK 2026 rooflight installation cost by size, type (fixed, centre-pivot, sun tunnel), glazing and roof covering. Includes flashing, structural alteration, plaster finish and 230V wiring.

Rooflight Installation Cost Calculator

Estimate UK 2026 rooflight installation cost by size, type (fixed, vented, sun tunnel), glazing and roof covering — VELUX, FAKRO, Keylite, Roof Maker — to BS 6262 and 2026 GBP labour rates.

Estimated rooflight cost
£1,810
Range: £1,539 – £2,172 · Per unit: £1,810
unit + flashing + framing + finish + add-ons
Rooflight units
£595
Flashing kits
£195
Framing / cut-in
£485
Plaster / shaft finish
£285
Add-ons
£0
Building control
£175
Skip / tip
£75
Total estimate
£1,810

What this calculator estimates

This calculator quotes the all-in installed price for a residential rooflight installation in 2026 pounds sterling. The bill is itemised the way a competent NFRC-member roofer or FENSA-registered glazier writes it:

  • Rooflight unit — the manufactured glazed assembly, priced by size and type. VELUX, FAKRO, Keylite and Roof Maker priced at trade-channel pricing 2026.
  • Flashing kit — manufacturer-spec EDX/EBL/EDW (or equivalent) profile interleave kit. Required for warranty.
  • Framing / cut-in — for a retrofit, this includes trimming and doubling rafters, upper and lower headers, and re-boarding the cut sarking.
  • Plaster / shaft finish — closing the internal ceiling around the opening, building a plaster shaft if attic depth requires it, two coats and decoration.
  • Add-ons — manual or motorised blinds, rain sensor for INTEGRA units, smart-home gateway, new 230V electrical run.
  • Building control — application fee for Building Notice or Full Plans submission.
  • Skip / tip — debris removal, typically a 4-yard mini-skip.
  • Weekend / out-of-hours premium — 25% surcharge.

A minimum call-out fee of £395 applies in most UK regions — even a single sun tunnel install carries this floor because mobilising a 2-person crew, scaffold or ladders, and PPE is the dominant cost.

How to use it

  1. Count the units — total rooflights installed in one mobilisation. Two on the same slope share scaffolding.
  2. Pick a size. Small is around 55x55 cm (an MK04 or M04 size in VELUX nomenclature). Medium is 55x118 cm (MK06 — the most common single-rafter size). Large is 78x118 cm (PK06 — a two-rafter trimmer). Oversize is anything above 114 cm wide (a custom or coupled unit).
  3. Pick type. Fixed for stairwells, top-of-stair landings, and inaccessible ceilings. Centre-pivot manual for loft conversion bedrooms and bathrooms with reachable handles. Top-hung or electric for premium installations and high ceilings. Sun tunnel for windowless rooms and corridors.
  4. Pick glazing. Argon-filled Low-E double is the 2026 default. Laminated safety glass over a bed or bath is mandatory under BS 6206. Triple is the energy-target spec (FAKRO FYP-V, VELUX 70 Q). Toughened Low-E is the impact-rated spec for coastal or high-exposure homes.
  5. Pick roof covering. Plain concrete tile or asphalt is the baseline. Clay tile adds 10-15% to flashing labour. Standing-seam metal adds 20%. Natural Welsh slate adds 60-70%. Flat membrane (EPDM or GRP on a flat-roof extension or dormer) adds 30% due to the curb detail.
  6. Pick work scope. Retrofit (cut a new opening) is the most common scenario and includes trimming, flashing, and plaster finish. New build (the carpenter leaves a trimmed opening ready for the unit) is significantly cheaper.
  7. Set storey count. Labour multiplier is 1.0x for single storey, 1.18x for two-storey, 1.42x for three-storey or higher.
  8. Toggle add-ons. Blinds, rain sensor, smart hub, new electrical run, Building Control fee, skip hire, and weekend premium each adjust the total.

Typical 2026 UK rooflight installation cost ranges

These ranges reflect 2026 nationwide pricing pulled from Checkatrade member averages, MyBuilder 2026 cost guide, NFRC member surveys, and direct quotes from VELUX-approved installers across English, Scottish and Welsh regional markets.

Configuration (concrete tile, retrofit, two-storey)2026 installed price
Sun tunnel (10-14 in / 25-35 cm)£495 – £980
Small fixed rooflight (55x55 cm)£810 – £1,520
Medium fixed (55x118 cm)£1,350 – £2,650
Medium centre-pivot manual (55x118 cm)£1,750 – £3,250
Medium INTEGRA electric / solar (55x118 cm)£2,450 – £4,250
Large fixed (78x118 cm)£2,050 – £3,950
Coupled / large pivot (114x118+ cm)£3,450 – £7,850

Add 10% for clay tile. Add 60% for natural slate. Add 20% for standing-seam metal. Add 30% for flat membrane (low-slope dormer or extension roof) because of the curb-mount detail.

Cost drivers

Unit type and size. The rooflight unit is 40-55% of the total bill on a standard installation. Stepping fixed → centre-pivot manual adds roughly 35%, fixed → INTEGRA electric adds 95%, fixed → solar-powered INTEGRA adds 70%.

Roof covering. Plain concrete tile (Marley Modern, Sandtoft, Russell) installs fastest with the matched EDW flashing. Plain clay tile is similar. Pantile (S-profile clay) needs the EDJ deep-profile kit and 1-2 extra labour hours. Natural Welsh slate is the most demanding — careful slate cutting, broken slate replacement (£8-£25 each), and patience prevent leaks at the flashing edges.

Retrofit vs new build. Cutting a new opening in an existing roof requires stripping tile or slate back 600 mm on all four sides, cutting the sarking and felt, trimming or doubling rafters, installing an upper and lower header, and adding new sarking and felt around the new opening. New build skips all of this — the carpenter leaves a trimmed rough opening before sarking goes on. New build is typically 35-45% cheaper installed.

Plaster shaft finish. A rooflight in a loft conversion under a sloping ceiling needs no shaft (the ceiling is the rafter line). A rooflight in a flat-ceilinged room with attic above needs a 600-1500 mm deep shaft, framed, insulated, plasterboarded, taped, mudded, sanded, and painted. The shaft alone can add £350-£1,100.

230V electrical run. An INTEGRA electric rooflight needs a switched live and neutral from the existing lighting circuit. If a junction box is nearby (often the case in a loft), the spark can tap it in 1 hour. If a new run is needed from the consumer unit, plan 3-6 hours of qualified Part P electrician time. Solar INTEGRA skips this — the integrated PV panel and battery drive the motor.

Scaffolding. Two-storey work at eaves height typically needs a 4-week standing scaffold (£480-£780 hire including erect/dismantle) or an alloy tower for shorter access (£180-£280/week). This is often a separate line in the quote.

Geographic spread. London and the South East are 20-30% above the national median. The South West, East, Midlands and Wales sit within 5% of median. The North East, Scotland and Northern Ireland are 5-10% below. Central London (postcodes EC, WC, W1, SW1) and prime central can be 40-50% above median, especially where Listed Building consent and conservation rooflights are required.

UK codes and standards

UK rooflight installation is governed by:

  • Approved Document Part L — energy efficiency. Maximum U-value 1.6 W/m²K for new rooflights (replacement); 1.0 W/m²K target for new builds achieving FEES.
  • Approved Document Part K — protection from falling. Glazing in critical locations (within 800 mm of floor over a stairwell, over a bath) must be safety-glazed to BS 6206.
  • Approved Document Part B — fire safety. Rooflights within 6 m of a boundary must be appropriately rated.
  • Approved Document Part F — ventilation. Trickle vents or background ventilation may be required.
  • BS 5516 — Patent glazing and sloping glazing for buildings. Specifies design loads, fixings, and weathering details.
  • BS EN 14351-1 — Windows and doors (including rooflights) — product standard, CE marking requirements.
  • BS 8000-7 — Code of practice for glazing.
  • FENSA / CERTASS / DGCOS — competent person schemes for self-certifying Building Regulations compliance.

Diagnostic step-by-step (before quoting)

  1. Measure the ceiling location and verify there is loft space above. If the rooflight is in a vaulted ceiling under finished rooms, install complexity rises sharply.
  2. Check the rafter spacing from inside the loft. Standard 400-600 mm centres comfortably accommodate a small or medium MK-size rooflight without cutting structural members.
  3. Check the roof pitch. Below 15° most rooflights need a curb extension or low-pitch-rated unit (Roof Maker, VELUX Low Pitch). Below 5° this becomes a flat-roof lantern detail.
  4. Note the roof covering and age. A 25+ year old concrete tile roof within 5 years of replacement is a poor candidate — the flashing assembly will need to be removed and re-installed at re-roofing.
  5. Identify SVPs, plumbing and wiring above the ceiling that may interfere with the rough opening.

Avoiding overcharging

The rooflight install market has a small but persistent rogue-trader problem. Red flags:

  • “Storm damage” claims after routine wet weather.
  • Pressure to sign before a written, itemised quote.
  • Cash-only or wire-transfer demands.
  • Refusal to provide an NFRC, FENSA, CERTASS or trade-body registration number.
  • Bundling a £1,800 rooflight install into a £14,000 full re-roof at the first visit.
  • Substitute flashing kits — never accept a non-manufacturer flashing. Warranty is voided.

Insist on a written estimate that itemises the unit model, size, type, glazing spec, manufacturer flashing kit part number, framing scope, finish scope, Building Control responsibility, and skip hire. Get insurance and registration proof before any work begins. Most reputable installers happily provide VELUX 5-Star, FAKRO Pro or Keylite Approved Installer credentials.

Sources: 2026 Checkatrade Cost Guide; MyBuilder 2026 cost averages; NFRC member-survey averages; BBA Agrément certificates for VELUX, FAKRO, Keylite, Roof Maker; BS 5516; BS EN 14351-1; Approved Documents Part L, K, B and F 2026 editions; FENSA installer database.

Frequently asked questions

How much does a rooflight cost installed in the UK in 2026?
Most British homeowners pay £1,350 to £3,150 for a single medium fixed rooflight on a concrete tile roof in 2026, with a typical job (one 55x118 cm VELUX MK06 centre-pivot, argon-filled Low-E double glazing, retrofit cut, two-storey semi, skip hire and Building Control fee) coming in at around £1,840 fully installed. Stepping to a centre-pivot manual adds roughly £390-£780 to the unit price, an electric INTEGRA unit adds £950-£1,450 over fixed, and natural Welsh slate adds 60-70% to the labour over plain concrete tile. Source: 2026 Checkatrade Cost Guide, MyBuilder 2026 averages, NFRC member quotes from London, Manchester, Birmingham, Bristol, Edinburgh and Cardiff.
Do I need planning permission for a rooflight?
In England most rooflights are permitted development under Class C of Schedule 2 Part 1 of the Town and Country Planning (General Permitted Development) Order 2015, provided the rooflight does not project more than 150 mm from the roof plane, is not above the highest part of the roof, and is on a side elevation that does not face a highway. Building Regulations Part L (energy efficiency) and Part B (fire safety) approval is still required for every new rooflight regardless of planning — submit a Building Notice or Full Plans application to your local authority. Conservation areas, Article 4 directions, and listed buildings require formal planning consent and a heritage statement. Scotland and Wales have parallel but slightly different regimes — check with your local planning authority before ordering.
What is the difference between a rooflight and a skylight?
In British usage the two terms are interchangeable in the consumer market. Rooflight is the term used by the NFRC, BS 5516, and the major brands (VELUX, FAKRO, Keylite, Roof Maker). Skylight is the older domestic term and is more common in the US. Both refer to a glazed unit set into a sloped or flat roof to admit daylight. Conservation rooflight refers specifically to a flush-fitting cast-iron-framed unit used in heritage and listed properties — distinct in detail and significantly more expensive than a standard plastic-clad timber unit.
Can I install a rooflight myself?
A sun tunnel (Sun Tunnel / SunPipe) is a reasonable DIY for a confident homeowner — the kit includes the flashing flange, a flexible reflective tube, and a ceiling diffuser. Plan 6-10 hours and £325-£795 in materials for a daylight-only unit. A traditional centre-pivot or top-hung rooflight is NOT a DIY-friendly job: framing a trimmed rough opening requires doubling rafters, the manufacturer's flashing kit must be interleaved precisely with the tile or slate courses, and the internal plaster shaft requires interior trade skills. The failure rate among DIY rooflight installations exceeds 30% in the first year (leaks, condensation, voided warranty). For Building Regulations compliance the installer must self-certify under FENSA, CERTASS or a competent persons scheme, or Building Control will charge for an inspection — DIY installations cannot self-certify.
Are rooflights energy efficient?
A modern argon-filled Low-E double-glazed rooflight is rated to U-value 1.0-1.4 W/m²K — better than most installed double-glazed windows. Triple-glazed units (VELUX 70 Q, FAKRO FYP-V) hit 0.8 W/m²K and qualify for the highest Approved Document Part L band. The actual heating bill effect depends on orientation (south and west elevations gain useful winter solar heat, mitigate summer overheating with electric blinds or external awnings), and on whether the unit is vented (good for kitchens, bathrooms and stairwell stack ventilation, lowers summer cooling load on heat-pump-conditioned homes). ENERGY STAR is a US scheme; the UK equivalent is BFRC (British Fenestration Rating Council) rated A++ to E.
What is the typical UK rooflight warranty and lifespan?
VELUX gives a 10-year warranty on the unit and 20 years on the glazing seal. FAKRO matches that. Keylite gives 10 years across the unit. The realistic service life of a polyurethane-clad pine timber rooflight installed under BS 5516 is 25-30 years before the glazing seal fails or the gasket degrades. Aluminium-clad versions add 5-10 years. The flashing kit (an EDX or EBL profile for plain tile, EDW for slate, EDJ for deep-profile tile, etc.) when installed correctly matches the roof system life. The most common premature failure is a head-flashing leak due to incorrect course interleaving — a workmanship issue, not a defect.
How long does rooflight installation take?
A single retrofit rooflight on an existing concrete tile roof takes 6-10 hours of crew time on the roof plus 4-8 hours of interior work for the plaster shaft and finish — typically completed in 1.5 days from the householder's perspective. A natural slate roof adds 3-5 hours per unit because of the careful slate cutting needed to maintain the watertight courses. Sun tunnels install in 3-5 hours total. Multiple rooflights on the same roof slope share mobilisation and add only 4-6 hours per additional unit. Scaffolding hire (typical £180-£420 for a 7-day standing scaffold to a two-storey eaves) is often a separate line.
What size rooflight should I specify?
The BS 5516 / Approved Document Part F minimum daylight calculation: total glazed area of rooflights should be 20% of the floor area in the room they serve (1/5 rule). For a 12 m² loft conversion bedroom, that is around 2.4 m² of glazing — typically two MK06 (55x118 cm) units or one PK08 (94x140 cm) plus a smaller unit. The maximum reach height (Part K) requires that the top of the operating handle is between 800 mm and 2200 mm above the finished floor — a centre-pivot rooflight handle sits at the base, so the unit must be installed correspondingly low. For top-hung VELUX GPL units the handle is at the top, so they can install higher.

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