Royal Borough of Windsor and Maidenhead

Adopted Documents We Assess Against

Documents are re-checked against the council's own website weekly. A detected change flags "Policy Update Available" for human review — live assessment standards are never replaced automatically.

Royal Borough of Windsor and Maidenhead standards at a glance

2 numeric standards taken from Royal Borough of Windsor and Maidenhead's own adopted documents, each shown with the paragraph it comes from. Figures differ between councils — these are this one's.

Rear extension depth

up to 3m

Where a single-storey extension in the Royal Borough sits within 2 metres of a side or rear boundary, keep the eaves height to about 3 metres there. Borough Wide Design Guide SPD Principle 10.4(3)

Side extension form

at least 1m

A side extension in the Royal Borough should normally leave at least 1 metre to the boundary, to preserve the gap between houses along the street. Borough Wide Design Guide SPD paragraph 10.14

Standards are what the council normally expects, not a guarantee. A scheme outside them can still be approved on its merits, and one inside them can still be refused for another reason.

Authored Policy Library

7 local policy checks, each citation-locked to the adopted document. National policy (NPPF, national space and daylight standards) applies alongside these.

Borough Wide Design Guide SPD

• Borough Wide Design Guide SPD Principle 10.4(3) — Rear extension depth Where a single-storey extension in the Royal Borough sits within 2 metres of a side or rear boundary, keep the eaves height to about 3 metres there.
• Borough Wide Design Guide SPD paragraph 10.14 — Side extension form A side extension in the Royal Borough should normally leave at least 1 metre to the boundary, to preserve the gap between houses along the street.
• Borough Wide Design Guide SPD paragraph 8.15 — Amenity neighbouring (2 checks) If a two-storey extension crosses a 45-degree line drawn from a neighbour's nearest window, expect closer scrutiny of daylight impact. Single-storey extensions are judged against a more generous 60-degree line instead. For a single-storey extension the Royal Borough uses a 60-degree line rather than the 45 degrees applied at two storeys, so there is more room before daylight becomes the issue. It is still only an indicator - levels and orientation matter too.
• Borough Wide Design Guide SPD Principle 10.5(2) — Roof alterations A dormer in the Royal Borough needs to sit well inside the roof slope - set back from the eaves and ridge, and no more than half the width or depth of that roof face.
• Borough Wide Design Guide SPD Principle 10.1 — Design materials An extension in the Royal Borough should read clearly as subordinate to the original house - matching its style and materials, using lower ridge heights and setbacks, and not eating into garden spaces that matter to the street's character.
• Borough Wide Design Guide SPD Principle 10.2 — Front extension A front extension or porch in the Royal Borough should not break the established building line along the street - it is really only likely to work where your house already sits well back from its neighbours.