CCTV drainage surveys
Build Over CCTV Survey
If proposed work is over or close to a public sewer or lateral drain, the relevant sewerage company may require a build over agreement and supporting survey information. We can help arrange pre-construction and post-construction CCTV surveys to the specification required for the site.
Why a build over survey may be required
Where building work is proposed over or close to a public sewer or lateral drain, the sewerage company may need to assess how the work affects the pipe and future access. The distance and application route vary by company, pipe and type of development, so the current requirements for the site should be checked before the survey is booked.
A CCTV survey can provide a record of visible pipe condition before work and, where required, after construction. Whether a pre-construction survey, post-construction survey or other evidence is needed depends on the sewerage company’s application process and the agreed scope.
We can help with CCTV surveys of public and private drainage for build over agreement applications, including the pre-works condition record and the post-completion check.
What the survey may need to show
The required survey content depends on the sewerage company and the application. Where specified, the report may need to cover:
- Condition of the sewer along the affected length, with defects coded to a recognised system
- Line and level, so the depth of cover and any change in gradient can be seen
- Manhole and inspection chamber positions, including covers, frames and benching
- Material and approximate diameter of the pipe
- Connections and junctions entering the length
Pipe depth, route and condition can be relevant to foundation design and the sewerage company’s assessment. The required measurements and any additional survey method should be agreed for the particular application rather than assumed from a standard CCTV scope.
Survey specification and coding
Some specifications require defects to be coded using MSCC5, the Manual of Sewer Condition Classification, while other applications use a different reporting requirement. The coding system and deliverables should be confirmed before the survey is booked.
Report contents depend on the agreed specification. Where the sewer route also needs to be established, a drain mapping exercise or other tracing work may be appropriate. If the sewerage company has issued a pro forma or a list of required fields, pass it on before the survey so the report can be specified around it.
Requirements vary between sewerage companies and application routes. Confirm whether the recipient needs footage, a condition log, plan, level information or any prescribed declaration before commissioning the work.
Avoiding gaps in a submission
A submission can be delayed or queried if information required by the sewerage company is missing. Depending on the stated requirements, points to check include:
- No depth or level information, so the assessor cannot judge cover over the pipe
- Missing manhole details, or chambers not opened and recorded
- The surveyed length stopping short of the full affected area
- Defects described in plain words rather than coded to the required system
- No plan showing the pipe in relation to the proposed structure
- Footage that is too dark, too fast or unlabelled to be followed
Use the sewerage company’s stated requirements as the survey specification. If an earlier submission has been queried, compare the report with the points raised before arranging further work.
Surveys before and after construction
Where a pre-works survey is required, it provides a condition record before construction that could affect the pipe. The length to be surveyed and any action required if defects are found should follow the sewerage company’s specification for the application.
Where a post-completion survey is required, it can be compared with the earlier record to identify visible changes. Access after construction may be different, so the survey extent and access points should be considered when the work is specified.
Time the survey around the application and construction programme, taking account of any point at which the sewerage company requires the condition record to be completed.
Conservatories, extensions and other structures
Do not assume that a conservatory, extension, garage or other structure is exempt. Whether an agreement or survey is required depends on the sewerage company’s current policy, the pipe and the proposed work.
The starting point is to establish whether a public sewer or lateral drain is present and where it runs. Sewer records may not establish the exact line on site. A sewer CCTV survey and, where needed, tracing or mapping can help investigate the drainage. The Build Over Agreement Checker sets out questions to put to the sewerage company for the site.
National differences and safety
Build over rules are set by the water company that owns the sewer, and the position differs across the UK. In England, Approved Document H of the Building Regulations covers foul water drainage and pipe protection, and the water company’s own build over policy sits alongside it. Scotland, Wales and Northern Ireland each have their own building standards and sewerage arrangements, so the requirements for a given site must be checked with the relevant authority and sewer owner rather than assumed from an English example.
Entry into manholes or chambers can involve confined-space risks and should be avoided where reasonably practicable. Where the Confined Spaces Regulations 1997 apply, the work requires appropriate risk assessment, precautions and emergency arrangements. CCTV equipment can often be operated without a person entering the chamber.
Cost and scheduling
Price depends on the length of sewer to be surveyed, the depth and diameter of the pipe, how many manholes need opening, whether the survey is inside a live highway, and the level of reporting the water company expects. A short shallow run between two chambers is a different job from a deep trunk sewer under a busy road with traffic management. A real quote is needed for a real site.
For a build over application, the useful information to have ready is the site address, the proposed structure and its distance from the sewer, any water company reference or pro forma, and the dates the build programme allows. That lets the survey be specified to match what the assessor will actually read.
Free online tool
Build Over Agreement Checker
Check what to ask your sewerage company before building near a drain or sewer.
Common questions
Frequently asked questions
Do I need a build over CCTV survey for a conservatory?
Possibly. A conservatory is not automatically exempt, but the need for a build over agreement or CCTV survey depends on the sewerage company's current requirements, the pipe and the proposed work. Confirm the requirements for the site before commissioning the survey.
What if the sewer is already damaged before work starts?
The pre-works survey records visible existing condition, including any defects within the surveyed area. If defects are found, provide the report to the sewerage company where required and follow its response. Any repair, further investigation or change to the application depends on the site and the company's requirements.
Who pays for the survey?
Who pays depends on the sewerage company's application route and the arrangements for the project. Some application fees may include specified survey work, while other surveys are commissioned separately. Check what the application fee covers before obtaining a separate quote.
Will the water company accept a survey coded to MSCC5?
Many do, but requirements vary and must be confirmed before the survey is booked. Some water companies issue a pro forma or a list of required fields, and some ask for a plan or level data alongside the coded log. Passing on the water company's stated requirements before the survey helps the report match what the assessor expects.
Can the survey be done after the build instead of before?
Follow the sewerage company's required sequence. Where a pre-construction condition record is required, a survey carried out only after the build cannot provide that earlier baseline. Some application routes also require a post-completion survey.
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