Velux & Skylights Maidstone

Roof window and skylight work across Maidstone — new installations, replacements, flat roof lanterns, dormer flashings and leak repairs. Below is what each costs and the flashing detail that decides whether it stays dry.

Roof Windows on Maidstone Property

Loft conversions on the post-war estates

The single largest source of roof window work in Maidstone is loft conversion on the 1960s and 70s estates — Penenden Heath, Park Wood, Coxheath, Larkfield and Shepway. These roofs are well suited to it: trussed or purlin-and-rafter construction at consistent 30 to 35 degree pitch, concrete interlocking tiles that take a standard flashing kit cleanly, and gable ends that allow straightforward internal layouts. A pair of Velux units in a converted loft on one of these properties is typically £2,800 to £4,500 fitted including making good. Where the roof is trussed rather than cut, structural work to form the opening is required and we flag that at survey rather than after the ceiling is open.

Key Fact

Velux and comparable manufacturers void their weathertightness guarantee where the flashing kit does not match the roof covering profile. Plain tile, interlocking tile and slate each require a specific kit, and substituting one for another is a leading cause of roof window leaks that are wrongly attributed to the window unit itself.

Plain tile flashing on the Victorian stock

Fant, Tovil, Upper Stone Street and the town centre carry clay plain tile roofs at steep pitches, and these need a different flashing kit entirely from the estate properties. Plain tile flashing kits accommodate the small tile module and the deeper batten gauge, and using an interlocking kit on a plain tile roof — which we are called out to fix more often than we would like — leaves gaps at the side abutments that admit water in wind-driven rain. Steeper pitch also means more of the window is exposed to direct rainfall running down the slope above it, so the head flashing detail has to be right.

Flat roof lanterns on the rear extensions

The rear kitchen extensions across the Maidstone estates increasingly take a lantern or flat roof light rather than a pitched roof window, usually as part of a wider kitchen project. These are a different job again: the upstand kerb must be built to the correct height above the finished membrane level, and the membrane must be dressed up and over the kerb before the lantern is seated. The most common failure we attend on Maidstone flat roof lights is an inadequate upstand — the kerb built flush or nearly flush with the roof surface, so any ponding reaches the seal. We build kerbs at a minimum 150mm above finished membrane level.

Dormer windows and the conservation question

Dormers on the Victorian and Edwardian properties around Fant and Boxley Road are typically original features needing repair rather than new additions. Cheek and front flashings on these are the weak point, and the lead is frequently original and long past its service life. Where a new dormer is proposed rather than repaired, planning matters: a dormer on a roof slope facing a highway within Maidstone town centre conservation area, Loose village, Bearsted village or the other designated areas is not permitted development and needs consent from Maidstone Borough Council. We advise on that before any work is priced.

Why roof windows leak in the Medway valley

Most roof window leaks we attend across Maidstone are not window failures. They are flashing failures, condensation misdiagnosed as leakage, or debris damming above the unit. The valley's humidity means condensation on the internal glass and frame is common on cold mornings, and homeowners reasonably assume a leak. The diagnostic is timing: genuine leaks appear during or shortly after rain, condensation appears on cold still mornings regardless of rain. On the wooded streets around Loose Road and Bearsted, leaf litter dams above the window head and backs water under the head flashing, which is a maintenance issue rather than an installation defect and is fixed with a clear rather than a re-flash.

Velux and Skylight Prices in Maidstone 2026

Work	Price	Notes
New Velux fitted (standard size)	£1,200 - £2,000	Includes flashing kit and making good
New Velux fitted (large or high level)	£1,800 - £3,000	Scaffold may be additional
Pair of units, loft conversion	£2,800 - £4,500	Typical estate loft conversion
Replace existing unit, same aperture	£900 - £1,800	No structural work required
Flat roof lantern fitted	£1,800 - £4,000	Includes kerb build and membrane dressing
Leaking roof window repair	£250 - £650	Re-flash, reseal or replace flashing kit
Dormer flashing renewal (Code 4 lead)	£450 - £1,100	Period property dormer cheeks and front
Structural trimming for trussed roof	£350 - £800	Where roof is trussed not cut

Prices include VAT, the flashing kit correct for your tile profile, and internal making good to plaster-ready finish. Decoration is not included. Scaffold on high-level or steep installations is named separately.

Loft Conversion Roof Windows: What to Get Right

Where a roof window is going in as part of a loft conversion, three decisions made early save money and problems later.

Position relative to the rafters. Standard Velux widths are sized to common rafter spacings, so a window positioned to fit between existing rafters avoids structural trimming entirely. Moving it 300mm to suit an internal layout can turn a one-day job into a two-day job with a structural trimmer. We survey rafter positions before the layout is finalised where the builder will let us.

Head height and Building Regulations. For a habitable loft room, the glazing area and the escape provision both matter. Where a roof window is intended as the means of escape, it must meet the minimum clear opening dimensions, and not every unit does. Getting this wrong is discovered at building control sign-off, which is the worst moment to discover it.

Insulation continuity at the reveal. The reveal around a roof window is a classic thermal bridge and a classic site of black mould two winters after a conversion. The insulation must be carried around the reveal and sealed to the window frame, not simply butted up to the plasterboard.

Repairing Rather Than Replacing

A roof window that leaks does not usually need replacing, and we will say so rather than quote the bigger job.

The first check is the flashing kit and whether it matches the tile profile. On Maidstone plain tile roofs particularly, we regularly find interlocking kits fitted by a previous installer, which leaves the side abutments unsealed against wind-driven rain. Replacing the flashing kit alone is £250 to £650 against £900 upward for a new unit.

The second is the seal and the drainage channels in the frame. Velux units have drainage channels that clear water from the frame, and they block with grit and moss over ten to fifteen years. Clearing them and renewing the seals restores function on a unit that is otherwise sound.

Genuine replacement is warranted where the frame timber has rotted, the sealed unit has blown, or the mechanism has failed beyond parts availability. On units over twenty-five years old the parts question usually settles it.