Quick Answer

Repairs and Maintenance

Routine roof maintenance and repair does not constitute development and does not need planning permission. This includes replacing broken or slipped tiles, re-felting or re-battening the roof, repairing or replacing flashings, repointing ridge tiles or chimney stacks, replacing guttering and fascias, and adding or replacing roof insulation.

Even a full re-roof using the same materials doesn’t need permission — it’s maintenance of the existing structure. The question becomes more complex when the materials change significantly (particularly in conservation areas) or when the work goes beyond maintaining the existing structure to altering it.

Changing the Roof Shape or Pitch

Altering the shape of a roof — raising the ridge height, converting a hip-end to a gable (hip-to-gable), changing the pitch, or raising eaves — constitutes development and requires planning permission unless it falls within permitted development limits.

A hip-to-gable conversion is development and is only permitted development on a detached or semi-detached house where it’s combined with a rear dormer extension under Part 1, Class B of the GPDO 2015, subject to volume limits (not exceeding 40m³ on a detached house or 20m³ on other types). Raising the ridge height or changing the overall profile of the roof in a way not covered by Part 1 Class B or Class C requires a full planning application.

Dormer Windows

Dormer windows are permitted development under Part 1, Class B of the GPDO 2015, subject to conditions:

Front dormers (on the principal elevation facing the highway) are not permitted development and require planning permission. They are often refused in traditional residential streets unless the design is very carefully handled.

Rooflights and Skylights

Installing rooflights (flat to the roof, e.g. Velux windows) is permitted development under Part 1, Class C of the GPDO 2015, provided the rooflight does not protrude more than 150mm above the existing roof plane, no part of the rooflight is higher than the highest part of the roof, and rooflights on the principal elevation more than 1.7m above floor level must be obscure-glazed.

A standard Velux-type window that sits flush with the roof slope will normally be permitted development without any application needed.

Conservation Areas and Listed Buildings

In conservation areas, Article 4 Directions often restrict changes to roof materials and coverings that would otherwise be permitted. Replacing natural slate with concrete tiles, or changing clay pantiles to interlocking concrete tiles, might need planning permission in a conservation area where the Article 4 covers roof alterations.

Additionally, in conservation areas, any extension or alteration that would be visible from a highway — including a rear dormer that can be seen from the street — requires planning permission. For listed buildings, virtually any alteration to the roof requires listed building consent — the roof is often a significant part of a listed building’s architectural character.