Velux Windows in Warwickshire: Installation, Repair and Planning — A Complete Guide

Velux and equivalent roof windows are among the most technically demanding single elements of domestic roofing when it comes to waterproofing. A correctly installed Velux on a compatible roof is watertight for 25 or more years. An incorrectly flashed Velux is one of the most common persistent-leak calls we receive across Stratford and Warwickshire. This guide covers what correct installation involves, the most common repair issues and the planning implications.

How a Velux Window Works

A roof window consists of three elements from a waterproofing perspective: the window frame itself, the upstand flashing that creates a weathertight surround at the window opening, and the tiles or slates that are cut and re-laid around the window. The upstand flashing — supplied as a kit by Velux and Fakro — must be selected to match the specific tile profile and roof pitch. Using the wrong flashing kit for the tile type is the most common installation error and the primary cause of Velux leaks on Warwickshire properties.

Roof window flashing kits must be matched to the tile or slate profile per the manufacturer's installation instructions; using an incompatible kit is the most common cause of roof-window leaks recorded in our own field data (2024).

— Stratford Roofing Experts field data, 2024

Velux Flashing Kits: The Compatibility Question

Velux supply multiple flashing kit types for different tile profiles and roof pitches. The most common UK residential kit types are:

• EDJ / EDW (standard): for most concrete interlocking tiles at pitches 15–90°. The default kit for most Warwickshire estate properties.
• EDL (low pitch): for roofs between 15° and 25° pitch. Required for shallow-pitch garages and some 1970s extensions.
• EDP (plain tile): specifically designed for clay plain tiles. Required for Victorian and Edwardian properties with plain tile roofs — using an EDJ kit on a plain tile roof creates a incorrect detail.
• BDX (conservation): for slate roofs and thin profiles. Required for Welsh slate properties and Cotswold stone slate contexts.

If you have a Velux that leaks and a roofer is suggesting the window unit itself has failed, it is worth confirming that the correct flashing kit was originally installed. In our experience, the majority of leaking Velux windows in Warwickshire have a flashing compatibility issue rather than a window unit failure.

Planning Permission for Velux Windows in Warwickshire

Rear elevation roof windows that do not protrude more than 150mm above the existing roof plane are generally permitted development on non-listed, non-conservation properties. Front elevation roof windows require planning permission regardless of size. Conservation area properties require pre-application advice — rear elevation Velux may be permitted but the conservation officer's view should be sought before installation. Listed buildings require listed building consent for any new roof window.

Installation Costs in Warwickshire 2025

Work Type	Cost Range	Notes
New single Velux installation	£600–£1,400	Window, correct flashing kit and labour.
Flashing kit replacement	£250–£600	Correct kit for tile type. Existing window retained.
Seal and draught repair	£100–£300	Handle, stay and minor seal replacement.
Two windows, same visit	£1,000–£2,200	Significant labour saving over separate visits.

Common Velux Repairs on Warwickshire Properties

The most frequent Velux repair calls we receive: flashing kit replacement where the original kit was incompatible with the tile profile; re-bedding of the surround tiles that have slipped from incorrect cutting at the original installation; and handle and seal replacement on windows from the 1990s and early 2000s. All are straightforward half-day to one-day jobs.