London Borough of Islington

Adopted Documents We Assess Against

Development plan: Islington Local Plan: Strategic and Development Management Policies (adopted 28 September 2023)

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.

London Borough of Islington standards at a glance

4 numeric standards taken from London Borough of Islington's own adopted documents, each shown with the paragraph it comes from. Figures differ between councils — these are this one's.

Basement

up to 50%

An Islington basement can sit under less than half the original garden, counting any basement already there. There is a second, separate test against the footprint of the house, and the tighter of the two wins. Islington Local Plan Policy DH4, Part D(i)

up to 50%

The part of the basement that reaches beyond the house can be up to half the footprint of the house. On a small house with a big garden this is the test that stops you, not the garden one. Islington Local Plan Policy DH4, Part D(i)

up to 3m

Islington cap basement height at 3 metres - unusually, this is a ceiling rather than a minimum. A tall basement that would be welcomed in another borough is refused here. Islington Local Plan Policy DH4, Part D(iii)

at least 1m

A metre of soil goes back over an Islington basement that reaches past the house, plus 200mm of drainage on top of that. Near big trees they will want up to 1.5 metres. Islington Local Plan, deep soil and trees

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

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

Islington Local Plan: Strategic and Development Management Policies (2023)

• Islington Local Plan Policy DH1 — Design character (provisional citation) Islington will judge how well your proposal responds to the host building and street. Their Urban Design Guide is the practical reference for extensions - worth reading before you finalise the drawings.
• Islington Local Plan Policy DH2 — Heritage constraints (provisional citation) If your property is in one of Islington's conservation areas, the proposal has to conserve or improve the area's character - a heritage statement is normally expected.
• Islington Local Plan (residential amenity policies) — Amenity neighbouring (provisional citation) Islington will look at the effect on your neighbours' light, outlook and privacy. Show the relationship to their windows on your drawings.
• Islington Local Plan Policy DH4, Part D(i) — Basement (2 checks) An Islington basement can sit under less than half the original garden, counting any basement already there. There is a second, separate test against the footprint of the house, and the tighter of the two wins. The part of the basement that reaches beyond the house can be up to half the footprint of the house. On a small house with a big garden this is the test that stops you, not the garden one.
• Islington Local Plan Policy DH4, Part D(iii) — Basement Islington cap basement height at 3 metres - unusually, this is a ceiling rather than a minimum. A tall basement that would be welcomed in another borough is refused here.
• Islington Local Plan, deep soil and trees — Basement A metre of soil goes back over an Islington basement that reaches past the house, plus 200mm of drainage on top of that. Near big trees they will want up to 1.5 metres.

Islington Urban Design Guide SPD (January 2017)

• Urban Design Guide SPD paras 5.134 to 5.139 — Rear extension depth Islington does not publish a depth limit in metres. They judge a rear extension by storeys: full width should stay a storey below the eaves. Their 45-degree line has to be drawn on both the plan and the elevation.
• Urban Design Guide SPD paras 5.154 to 5.162 and Figure 23 — Roof form Islington allow one extra storey in the roof. A mansard should run at about 72 degrees then 30 degrees to the ridge. Dormers and rooflights are sized against the windows below them rather than to a set dimension.