Planning drawings in Hillingdon, £895 fixed

What is the householder approval rate in Hillingdon?

Hillingdon Council granted 1,035 of 1,147 householder decisions (90.2%) from 1 July 2025 to 30 June 2026, with larger home extension prior approvals counted in. That is 4.4 points above London's 85.8% (20,556 of 23,967), and 112 of its 1,147 decisions were not granted. Rank 11 counts the 32 boroughs with 50+ decisions (one has fewer). Source: MHCLG PS2. Compare all boroughs: London approval rates table.

What does Hillingdon Council need to validate an application?

• Hillingdon’s February 2024 validation checklist asks every householder application for an existing and proposed block plan at 1:500 as well as floor plans and elevations. (source)
• Any householder scheme that includes a basement needs a basement impact assessment or structural survey. (source)
• In flood zone 2 or 3, a basement or ground-floor extension needs the Environment Agency flood risk matrix. (source)
• A heritage statement is needed in a conservation area or for a listed or locally listed building, and a tree survey if you would fell a protected tree or a tree in a conservation area. (source)
• Householder applications must also include the data required by the Greater London Authority data standard and vehicle parking and access details. (source)

Article 4 directions in Hillingdon

three Article 4 directions below remove permitted development rights in Hillingdon. Check an address with the permitted development checker.

• Large rear extensions, borough-wide (2014). Since 22 September 2014 a single-storey rear extension reaching more than 4 metres beyond the original rear wall has needed planning permission anywhere in the borough. (source)
• Small HMOs, borough-wide (December 2025). The council’s page says planning permission is now needed to convert a house to an HMO for three or more unrelated people anywhere in Hillingdon, where before it applied only in Brunel and Uxbridge South. (source)
• Small HMOs: confirmation (26 February 2026). Full Council resolved on 26 February 2026 to confirm the borough-wide immediate direction removing the right to turn a house (Class C3) into a small HMO (Class C4). (source)

Hillingdon has 31 conservation areas, from old village centres and planned residential estates to canal-side and historic industrial areas. (source)

How long does a planning decision take in Hillingdon?

Hillingdon decided 678 householder applications from 1 July 2025 to 30 June 2026, prior approvals excluded; 637 of them (94%) took eight weeks or less.

• Pre-application advice for small-scale minor proposals, which the council says includes certificates of lawfulness, prior approvals and complex or large extensions, costs £504 including VAT. (source)
• For a fast-track fee, the council will decide a householder lawful development certificate within 21 days, or a householder prior approval within 28 days. (source)

Design guidance: Local Plan Part 2, Policy DMHD 1 (January 2020). Adopted 16 January 2020, it limits single-storey rear extensions to 3.3m deep on terraced or semi-detached houses with plots up to 5m wide, 3.6m on wider plots and 4.0m on detached houses, with flat roofs no higher than 3.0m. Its design appendix says only rear roof extensions and rear dormers will be considered acceptable.

Drawings and prices in Hillingdon

• architectural drawings service for Hillingdon homeowners: £895.
• drawings for building control approval: £795.
• plans for a rear, side or wraparound extension

Do I need planning permission? · Certificate of lawfulness from £950.

Neighbouring councils

Council facts checked 14 October 2026.