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 |
Do I Need A As Built Survey
The question "do I need an as built survey?" comes up frequently in property projects — and the honest answer is: it depends on what you are doing with the property, what the planning authority requires, and what your downstream stakeholders (architects, contractors, lenders) expect.
This guide covers the situations where an as built survey is mandatory, where it is strongly recommended, and where you can reasonably proceed without one. If after reading you are still uncertain, contact us — we will tell you honestly whether a survey is necessary for your specific project.
When an As Built Survey Is Mandatory
There are specific situations where a measured building survey is not optional — it is a requirement of law, regulation, or established professional practice.
Planning applications for extensions and new builds If you are submitting a planning application for a house extension, loft conversion, new build, or change of use in England, the local planning authority will require existing drawings of the building as it currently stands. Without these, the application will be rejected at validation. The drawings must be to scale and must reflect the building as it actually exists — not what the plans from the 1970s suggest should be there.
Listed building works Any works to a Grade I, Grade II*, or Grade II listed building require a measured building survey as part of the Heritage Impact Assessment submitted with the Listed Building Consent application. The survey must be to RICS Level 3 accuracy standard and must include detailed recording of architectural features.
Building control completion certificates Loft conversions, extensions, and basement works require accurate record drawings for the building control completion certificate. These drawings confirm that the works have been carried out to the approved design and must reflect what was actually built.
Commercial property lettings and sales RICS-compliant floor area measurements (NIA and GIA) are required for virtually all commercial lettings and sales in England. The measured building survey provides the drawings and the measurement schedule. Without it, you cannot accurately market the space and the transaction may not complete.
Construction handover At practical completion of a new build or major refurbishment, verified as built drawings demonstrate that the works have been completed to the design specification. This is a standard requirement in most construction contracts and is frequently insisted upon by employers and funders.
When an As Built Survey Is Strongly Recommended
Even when not strictly mandatory, there are situations where commissioning an as built survey will save you money, reduce risk, and prevent disputes downstream.
Before instructing an architect If you are instructing an architect to design an extension, conversion, or new build, you need accurate dimensions before the architect can produce a meaningful design. Design decisions made from approximate measurements frequently need to be revised — which costs time and money. A measured building survey at the design inception stage eliminates this risk.
Before exchanging contracts on a development site If you are acquiring a development site with an existing building, you need verified floor areas, accurate building dimensions, and an understanding of the structure before you exchange contracts. The measured survey data protects you from overpaying for a site that does not deliver the floor area you expected.
Before listed building works (even without consent) Even if your proposed works to a listed building do not require Listed Building Consent (which is rare), a measured survey before any intervention protects the building's historic fabric by ensuring that any fixings, services, or alterations are positioned accurately without exploratory damage.
When coordinating with neighbours over boundary works If you are carrying out works near a shared boundary — a loft conversion that extends to the boundary wall, a basement that goes under the neighbouring property, or works that affect a party wall — accurate survey data helps your surveyor and your neighbour's surveyor agree on the existing conditions more quickly.
For BIM coordination on complex projects If your project involves multiple design disciplines (architecture, structure, MEP) working in a coordinated BIM environment, the measured survey provides the existing building model. This eliminates the need for the design team to model the existing building from scratch and significantly reduces coordination errors.
When You May Not Need an As Built Survey
There are situations where a measured building survey may not be necessary — though you should always confirm this with the relevant planning authority or building control before proceeding.
Simple permitted development with no planning requirement If your proposed works are covered by permitted development rights and do not require a planning application, building control may not require existing drawings. However, even in this situation, if you are using an architect or structural engineer, they will need accurate dimensions to design from.
Very minor works with no downstream documentation need If you are carrying out works that will never be documented, sold, financed, or inspected by a third party, a survey may not be required. This situation is rare in practice — even minor works frequently trigger downstream requirements (a mortgage lender, a lease extension, a neighbour's surveyor) that make a survey necessary.
Properties with recent accurate surveys If a property has been surveyed accurately within the last two to three years and you have access to the drawings, you may be able to use those existing drawings rather than commissioning a new survey. This depends on whether the property has changed since the survey was completed.
The Difference Between an As Built Survey and Other Surveys
There are several types of survey in the UK property market and it is easy to confuse them. Here is a brief explanation of how they differ.
As built survey vs. RICS Home Survey (Level 1, 2, 3) RICS Home Surveys are condition surveys — they assess the physical condition of a property and identify defects. They are not designed to produce accurate floor plans or dimensions. An as built survey is a measured survey — its purpose is to produce accurate spatial data, not to assess condition. The two serve different purposes and are not interchangeable.
As built survey vs. boundary survey A boundary survey (sometimes called a location plan or topographical survey) measures the site boundaries, topography, and external features of a property. An as built survey measures the building interior and exterior. Both may be needed for a planning application — they are not alternatives to each other.
As built survey vs. Snagging survey A snagging survey is a defect-focused inspection of a new build property at practical completion, looking for incomplete or defective works. An as built survey records dimensions and geometry, not defects. A snagging survey and an as built survey may be commissioned together at the end of a new build project.
What Happens if You Skip a Survey When You Need One
The consequences of proceeding without a required survey vary by situation but can be serious:
Planning application rejection — If you submit a planning application without the required existing drawings, the planning authority will reject it at validation. You will need to commission a survey, wait for it to be completed, and resubmit. This adds four to six weeks to your programme and costs more than commissioning the survey at the outset.
Building control delay — If you proceed with works without the required record drawings for building control, the building control surveyor may require them before issuing a completion certificate. This can delay occupancy and trigger additional costs.
Design errors — If you design from approximate dimensions and the building does not match your drawings, the design will need to be revised. This is particularly costly at the planning stage — revised drawings mean a resubmission, additional planning fees, and programme delay.
Disputes with neighbours — If you carry out works near a shared boundary without accurate survey data, disputes with neighbours over boundary positions, wall thicknesses, and structural junctions become more likely and more difficult to resolve.
How to Decide
Ask yourself these questions:
- Does my planning authority require existing drawings? If yes, you need a measured building survey.
- Does my lender require a survey? If you are using mortgage finance, the lender will have requirements.
- Does my architect need accurate dimensions to work from? If yes, commission a measured building survey before design begins.
- Is this a listed building? If yes, you need a measured building survey to RICS Level 3 standard.
- Is this a commercial property letting or sale? If yes, you need RICS-compliant floor area measurements from a measured building survey.
- Am I coordinating multiple design disciplines in BIM? If yes, you need a scan-to-BIM survey.
If you answered yes to any of these questions, commission an as built survey. If you are still unsure, contact us — we will give you a honest assessment of whether a survey is necessary for your specific project.
Get Started
To commission an as built survey, provide us with:
- The property address and postcode
- The project type (planning, building control, commercial transaction, BIM, etc.)
- The approximate floor area and number of floors
- The output format you require (CAD, BIM, point cloud, or a combination)
- Your required delivery date
We respond to all enquiries with a fixed fee within one working day.