Measured Building Survey for Planning Permission: UK Guide
For a planning application in the UK, you need a measured building survey of any existing structures that will be altered, extended, or tied into the new work. Accurate existing drawings are a mandatory validation requirement from local planning authorities — submitting rough or outdated drawings is a common cause of application delays or refusals.
When You Need a Survey for Planning
| Scenario | Survey Required? | | --- | --- | | House extension | Yes — all existing floors and elevations | | Loft conversion | Yes — full survey of existing building | | Change of use | Yes — for existing structure documentation | | New build adjacent to existing | Yes — boundary and existing structure | | Internal refurbishment | Yes — for structural alterations | | Minor works, no structural change | Usually no — confirm with LPA |
What LPAs Require
| Drawing | Scale | Purpose | | --- | --- | --- | | Floor plans (all levels) | 1:50 or 1:100 | Internal layout | | External elevations (all sides) | 1:50 or 1:100 | Existing appearance | | Cross-sections | 1:50 | Floor-to-ceiling heights | | Roof plan | 1:100 | Roof features | | Site layout | 1:200 or 1:500 | Boundary context |
2025 UK Costs
| Property Type | Cost (ex VAT) | | --- | --- | | 1–2 bed flat | £350–£450 | | 3–4 bed house | £500–£750 | | Small residential extension | £800–£2,000 | | Typical house (~350m²) | £1,500–£2,200 | | Medium office or retail (<300m²) | £650–£1,200 | | Large commercial (>500m²) | £1,200+ | | Heritage or complex commercial | £5,000–£50,000+ |
Survey Standards
Use RICS-qualified surveyors following the RICS Measured Surveys of Land, Buildings and Utilities, 3rd edition (April 2024). All drawings metric and to scale — no "do not scale" markings accepted for planning.
Frequently Asked Questions
Q: Is a measured building survey mandatory for planning?
Yes for extensions, alterations, and change of use. Confirm exact requirements with your local planning authority.
Q: Can I use previous drawings from conveyancing?
No — conveyancing plans are not accurate enough for planning. Commission a fresh measured survey.
Q: What scale is accepted?
1:50 or 1:100 for floor plans and elevations. Confirm with your LPA.