Why Drain Surveys Are Essential Before Building Your Home Extension
Planning a home extension is an exciting project, but before you start, it is important to make sure your drains are ready. Many extensions in Derby and Derbyshire are built near or directly above existing drainage systems, and building without checking their condition can lead to serious problems later.
A professional Build Over Drain Survey ensures your project meets Severn Trent Water regulations and prevents costly issues such as structural damage, collapsed pipes, or planning delays. At Derby Drain Surveys, we help homeowners and builders throughout the Midlands understand their drainage layout and secure approval before construction begins.
What Is a Build Over Drain Survey?
A Build Over Drain Survey is a CCTV inspection carried out before, during, or after construction to assess the condition and layout of existing drainage systems. It is designed to confirm whether it is safe to build near or over public sewers and private drains.
The survey uses advanced high-definition cameras to map and record the drain’s location, structure, and condition. The resulting report is required by local authorities and Severn Trent Water before they will approve your building work.
Why You Need One Before Starting an Extension
If your extension or renovation project is close to a shared or public sewer, you must obtain permission from Severn Trent before building. Skipping this step can lead to major issues such as:
Planning rejection: Your application may be refused if drainage layouts are not verified.
Legal complications: Building over a drain without approval can violate water authority regulations.
Structural risks: Damaged or weak pipes could collapse under new foundations.
Future maintenance challenges: Builders may block access to critical drains, making future repairs expensive.
A Build Over Drain Survey ensures your plans are compliant, safe, and documented for future reference.
What the Survey Includes
Our Derby Drain Surveys team provides a detailed inspection and full report that includes:
Drain location mapping to show where pipes run under or near the build site
Condition assessment to identify cracks, blockages, or weak points
HD video footage with time-stamped evidence
Written report suitable for submission to Severn Trent Water
Professional recommendations for any necessary repairs or adjustments
We also offer post-construction surveys to confirm that no damage has occurred during your build, ensuring compliance from start to finish.
Common Problems Found in Build Over Drain Surveys
In many Derbyshire properties, especially older homes, the drainage system may not match current records. Our surveys often reveal issues such as:
Misaligned or collapsed pipes beneath planned foundations
Tree root ingress near boundary lines
Shared sewers running through private gardens
Incorrect pipe gradients causing poor flow
Previous patch repairs that have started to fail
Identifying these problems early allows for affordable repairs before the foundation work begins, preventing long-term damage and delays.
The Build Over Process Explained
The process is straightforward when managed correctly:
Pre-Construction Survey: We perform a CCTV inspection to locate drains and check their condition.
Submission to Severn Trent: You or your architect use our report to apply for build-over approval.
Construction: Once approved, building work can proceed with drainage protection in place.
Post-Construction Survey: After work is complete, we re-inspect to ensure no damage has occurred.
Our reports meet all Severn Trent standards and are accepted by building control and insurance companies.
How a Drain Survey Saves You Money
A simple Build Over Drain Survey costing a few hundred pounds can prevent thousands in potential repair costs. Without one, you risk hitting a drain during excavation or facing rejection from Severn Trent, forcing costly redesigns or delays.
By confirming your drainage layout and condition early, you can plan your build confidently, knowing your project meets every requirement.
Why Choose Derby Drain Surveys
With over 20 years of experience in drainage and construction, our team understands exactly what local authorities and water companies require. We have helped hundreds of homeowners and builders across Derby, Burton, Hilton, and the Midlands secure approvals quickly and avoid costly issues during construction.
We offer:
HD CCTV inspections and detailed written reports
Compliance-ready documentation for Severn Trent Water
Fast, affordable service with flexible scheduling
Clear, honest advice from local experts
We are trusted by builders, surveyors, and architects across Derbyshire for our professionalism and reliability.
Build Smart, Not Risky
Before you break ground, take the time to inspect and document your drains properly. A Build Over Drain Survey is a small but vital step that ensures your project runs smoothly, safely, and in full compliance.
Click here to book your Build Over Drain Survey or learn more about our professional CCTV drain inspections for home extensions in Derbyshire.
📍 Based in Derby. Serving Derbyshire, Burton, Hilton, and surrounding Midlands towns.
