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 in London
An as built survey captures a building exactly as it exists — not as it was designed, not as old drawings suggest it should be, but as it stands on the day the survey is carried out. In London, where property stock ranges from Georgian terraces to modern commercial shells and where planning authorities require accurate existing drawings before they will validate any application, a measured building survey is often the first technical document commissioned on any project.
This guide explains what is included in a standard as built survey in London, what deliverables you receive, and how the process works from brief to delivery.
What Is Included in an As Built Survey
A measured building survey in London is not simply a floor plan. A properly scoped survey includes everything needed to represent the building accurately for planning, design, construction, or commercial purposes.
Floor plans — Every as built survey includes room layouts with dimensions, floor area calculations, and the relationship between spaces. Floor plans are the primary deliverable for any planning or building control application in London.
Elevations — All accessible external faces of the building are surveyed and drawn. For residential properties this means front, rear, and both sides. For commercial properties with multiple street frontages, all accessible elevations are included.
Sections — Cross-sections through the building showing floor-to-ceiling heights, ceiling voids, and structural zones. Sections are essential for basement applications, roof conversions, and any project where the vertical relationship between floors is material to the design.
Site plan — The position of the building relative to the site boundaries, adjacent structures, and hard landscaping. Site plans are a standard requirement for planning applications in London and must reflect accurate boundary positions — not drawn from an OS map.
Accuracy statement — A signed statement from the surveying firm confirming the survey accuracy standard. This is required by planning authorities for heritage applications and by building control for completion certificates.
As Built Survey Deliverables
The deliverables from a measured building survey in London depend on what you need the data for. Here is what is available and when each format is appropriate.
2D CAD Drawings (DWG)
AutoCAD drawings are the standard deliverable for every as built survey in London. They are the format required by London planning authorities, building control, and most contractors. CAD drawings are structured in layers that can be turned on and off depending on what you need to show — floor plans without furniture, electrical layouts, reflected ceiling plans.
DWG files are the native format that architects and engineers work in. If you are submitting to a London planning authority, they accept DWG drawings alongside a PDF version. The PDF is for reference and sharing; the DWG is the working document.
PDF drawings are included as standard with every survey deliverable. They are useful for sharing with clients, appending to reports, and submitting to planning portals that do not accept DWG uploads.
BIM Models (Revit)
A Revit BIM model is generated from laser scan data and represents the existing building as a 3D model. BIM models are increasingly required on new build and major refurbishment projects in London — particularly where the principal contractor is running a BIM execution plan or where the design team is working in a coordinated 3D environment.
The Level of Detail (LOD) in a BIM model determines how much information is embedded in it. LOD 300 includes floor plans, ceilings, and basic structural elements — sufficient for design coordination and space planning. LOD 350 adds detailed component specification — door schedules, window types, architectural finishes — useful for detailed design and specification.
BIM deliverables from an as built survey are priced per square foot of gross internal area and cost more than 2D CAD drawings. However, for projects where the design team would otherwise need to model the existing building from scratch, the scan-to-BIM workflow is significantly more cost-effective.
Point Cloud Data (RCP/RCS)
A point cloud is the raw output of a 3D laser scan — millions of measured points that represent the building's surfaces in three dimensions. Point cloud data is provided in RCP (Reality Capture) or RCS format and can be imported into CAD and BIM software for reference and modelling.
Point cloud data is typically used when the design team wants to model directly from scan data, when a digital twin is required for FM purposes, or when the geometry is too complex to be adequately represented by total station survey alone. For most standard residential and commercial applications in London, a point cloud is not required — 2D CAD drawings are sufficient and more cost-effective.
Area Measurement Schedules
For commercial property lettings and sales, RICS-compliant floor area measurements are required. These are calculated to the RICS Code of Measurement Practice 8th edition — the professional standard for measuring floor space in UK commercial property.
The measurement schedule is provided as a separate document alongside the drawings. It includes Net Internal Area (NIA), Gross Internal Area (GIA), and any other areas relevant to the letting or sale.
The Survey Process: From Brief to Delivery
Understanding how a measured building survey in London works helps you brief accurately and manage your programme.
Step 1 — Brief and scoping You provide the property address, approximate floor area, survey type required, and output format needed. We confirm the survey scope, accuracy standard, and delivery timeline. We respond with a fixed fee within one working day.
Step 2 — Site survey Our surveyor attends site with total station equipment or a laser scanner depending on the property type. For standard residential properties, the site survey typically takes half a day to one day. For larger and more complex buildings, multiple days may be required.
Step 3 — Data processing and quality check Survey data is processed in our office. All drawings are quality-checked against site notes, photographs, and control measurements before delivery. We do not release drawings that have not been independently verified.
Step 4 — Deliverables 2D CAD drawings are delivered as DWG and PDF via secure download. BIM models are delivered in Revit format. Point cloud data is delivered in RCP/RCS format. All deliverables include a signed accuracy statement.
Common Applications in London
Planning applications — London planning authorities require existing drawings for most applications — house extensions, loft conversions, change of use, new builds on existing sites. The drawings must be to scale, with dimensions noted, and must reflect the building as it actually exists.
Building control — Loft conversions, extensions, and basement works require accurate as built drawings for the completion certificate. These drawings confirm the works have been carried out to the approved design.
BIM coordination — New build and major refurbishment projects in London increasingly require BIM models for design coordination. The measured building survey provides the existing building model, which is integrated with the design model.
Commercial property transactions — Floor area measurements (NIA/GIA) are a standard requirement in commercial lettings and sales. The measured survey provides the drawings and the measurement schedule.
Handover surveys — At practical completion of a new build or major refurbishment, verified as built drawings confirm that works have been completed to the design specification.
Frequently Asked Questions
Q: What is the difference between an as built survey and a floor plan?
A floor plan is simply a drawing of the room layout. An as built measured building survey includes verified dimensions, floor areas, section cuts, elevation data, and a site plan — all to a specified accuracy standard. A floor plan is one output of a measured building survey, not a substitute for one.
Q: How long does an as built survey take in London?
For a standard residential property (up to 200m²), the site survey typically takes half a day to one day. Drawing delivery is usually 5–7 working days from the survey date. For larger properties and commercial buildings, timelines are agreed at scoping stage.
Q: Do I need a laser scan or is total station sufficient?
For most standard residential and commercial properties in London, total station survey is sufficient and more cost-effective. Laser scanning is recommended for complex geometries (irregular shaped rooms, curved facades, heritage properties with intricate detailing), large commercial properties, and projects where a BIM model is required. We advise on the appropriate method when you provide the brief.
Q: What accuracy standard do you work to?
We work to RICS measured survey specifications: Level 2 (positional tolerance 20mm at 95% confidence) for standard projects, Level 3 (10mm or better) for heritage and conservation projects. We specify the accuracy standard in our fee proposal and confirm it before survey.
Q: What format do London planning authorities accept?
London planning authorities accept DWG drawings with a PDF version. Our drawings are accepted by every London borough planning department. We are familiar with the validation requirements of each authority.