What As-Built Surveys Include
| Deliverable | Format | Use | | --- | --- | --- | | Floor plans | DWG + PDF | Design reference | | Elevations | DWG + PDF | Planning | | Sections | DWG + PDF | Building regs |
2025 As-Built Survey Costs (ex VAT)
| Property | Survey Cost | | --- | --- | | 2–3 bed | £400–£600 | | 4+ bed | £500–£800 | | Commercial | £800–£1,500 |
As Built Survey For Planning Permission
A measured building survey is required for a significant proportion of planning applications in England — whether for a house extension, a change of use, a new build, or work to a listed building. Understanding what planning authorities actually require from a survey, what format the drawings should be in, and how to avoid common pitfalls can save you weeks in the planning process.
This guide explains what you need to know about commissioning a measured building survey for planning permission.
When Do You Need a Measured Building Survey For Planning?
Not every planning application requires a measured building survey. Understanding when the council will ask for one — and what they expect — is the first step in avoiding a validation failure or a request for more information.
House extensions and loft conversions For a house extension or loft conversion, most London boroughs require existing floor plans and elevations as part of the application. If you are submitting drawings showing the proposed works overlaid on the existing building, the existing building must be accurately measured — not traced from an estate agent's floor plan or from memory. If the existing plans are inaccurate, the planning officer will flag it at validation and may reject the application.
Change of use applications If you are changing the use of a building — from office to residential, from retail to restaurant — the council will require accurate floor plans showing the existing building layout. This is particularly important for the licensing and fire safety elements of a change of use application.
New build on an existing footprint For new builds on sites with existing structures, planning authorities require a measured survey of the existing building before they will validate a new build application. This is especially common in urban areas where boundary positions and neighbouring building dimensions are contested.
Listed building consent Any works to a Grade II, Grade II*, or Grade I listed building require a measured building survey as part of the Heritage Impact Assessment. The survey must be to RICS Level 3 accuracy standard and include detailed recording of architectural features, fenestration, and historic fabric.
Conservation area consent For buildings in a Conservation Area, local planning authorities typically require existing building drawings as part of any application for works that would alter the external appearance of the property.
What Planning Authorities Require From a Measured Survey
Every London borough has slightly different requirements, but the common elements across most planning authorities are:
Existing and proposed drawings Your planning submission must include existing floor plans and elevations of the building as it currently stands, overlaid with the proposed works. The drawings must be to scale, with dimensions noted. If the existing plans are inaccurate, the planning officer cannot assess the impact of your proposed works against the existing context.
Site plan with accurate boundary positions A measured survey of the site boundary and its relationship to the building is required for most applications. This is particularly important for extensions that extend to the boundary, for works in Conservation Areas, and for listed buildings where boundary evidence is relevant to the heritage assessment.
Floor area calculations For change of use applications, planning authorities require GIA and NIA floor area calculations to RICS Code of Measurement Practice standards. These are used to assess the impact of the development on the local context and to verify compliance with space standards.
Accurate section drawings For applications involving changes to the roof profile, basement excavations, or works that alter the building's height, accurate section drawings are required. These are essential for assessing the impact on neighbouring properties' daylight and sunlight.
Common Mistakes That Delay Planning Applications
Inaccurate existing drawings If the existing floor plans do not accurately reflect the building as it exists on site, the planning officer will request revised drawings. This is one of the most common reasons for planning delays on householder applications. Commissioning an accurate measured survey at the outset avoids this.
Out-of-date surveys If the building has been significantly altered since the survey was completed, the drawings will not reflect the current state of the building. Planning officers sometimes spot discrepancies during their site visit. If you are commissioning a survey more than six months before submission, check whether the building has changed since the survey date.
Missing elevations or sections Planning applications require all accessible elevations — not just the front. If the side and rear elevations are not surveyed and included in the drawings, the planning officer will ask for them. This can be difficult if the property has been altered since the survey.
Incorrect scale All drawings submitted with a planning application must be to a recognised scale. The standard scales for floor plans are 1:50 and 1:100. If your drawings are not to a recognised scale, the planning officer will reject them at validation.
HowIcelabzHandles Planning Applications
We have provided measured building surveys for planning applications across every London borough. We understand the validation requirements of each authority and deliver drawings in the format each council expects.
We also accommodate revision requests when planning officers request additional information. Our average revision cycle is 3–5 working days, and we do not charge for revisions within the scope.
Frequently Asked Questions
Q: How accurate does a measured building survey need to be for a planning application?
For most householder applications in London, RICS Level 2 measured survey accuracy (positional tolerance 20mm at 95% confidence) is sufficient. For listed building applications and major development schemes, most planning authorities require RICS Level 3 accuracy (10mm or better). We specify the accuracy standard in our fee proposal based on your application type.
Q: How long does a measured building survey take?
For a standard residential property (up to 200m²), we typically complete the site survey within one day and deliver drawings within 5 working days. For larger properties and commercial buildings, timelines are agreed at scoping stage. We accommodate urgent requests where the planning programme requires it.
Q: Do I need to commission a new survey if I already have drawings from the 1990s?
Not necessarily — but if the drawings are more than a few years old, there is a reasonable chance the building has changed since they were produced. We can advise on whether an existing drawing set is sufficient for your application if you share it with us before commissioning a new survey.
Q: Can you provide surveys for listed buildings?
Yes. We have provided measured building surveys for Grade II, Grade II*, and Grade I listed buildings across London. Our drawings are accepted by every London borough planning department and Historic England for listed building consent applications.
Q: What format do you deliver drawings in?
Our standard deliverable is DWG (AutoCAD 2018 format) with a PDF version. We can also provide DXF, SVG, and Revit BIM format. If you have a specific format requirement for a planning submission, tell us and we will confirm feasibility.