Why Do I Need a BRE365 Infiltration Test?

In accordance with the drainage hierarchy, Sustainable Urban Drainage Systems (SuDS) prioritise the disposal of surface water runoff to ground via infiltration. This approach replicates natural drainage processes and is often the preferred solution for managing runoff from impermeable surfaces.

A preliminary desktop assessment, such as a SuDS report, can indicate whether infiltration is likely to be viable at a site. However, this must be verified through on-site testing to support both design and planning requirements.

Most clients understandably prefer not to pay for a BRE365 infiltration (percolation) test at the planning stage. However, without this information, there may be no suitable discharge point for surface water runoff.

As a result, many local authorities will object to your application and request a BRE365 test before granting approval — leading to delays and additional costs.

How Do I Arrange a BRE365 Infiltration Test?

At Nimbus Engineering, we provide BRE365 infiltration testing as part of our drainage and SuDS services, handling everything from site testing through to reporting for planning.

📞 Get in Touch

• Phone: 0800 061 4916

• Email: info@nimbusengineering.co.uk

• Website: Submit an enquiry via our contact form

What Information Do We Need?

Before providing a quote, we typically request:

• Site address and postcode

• Proposed development (e.g. extension, new build, commercial site)

• Any proposed site plans

• Existing reports (if not prepared by Nimbus Engineering)

• Proposed drainage strategy (if available)

• Depth of proposed test pits (if known)

• Any local authority correspondence requesting testing

• Water availability on site (or if supply is required)

• Site access or parking restrictions

What Happens During the Test?

Our team will attend site and carry out:

• Excavation of trial pits at proposed soakaway locations

• Filling and monitoring water levels (multiple cycles)

• Calculation of infiltration rates in accordance with BRE365 guidelines

This process determines whether soakaways or infiltration systems are viable.

Because we carry out all services in-house, our engineers remain in constant contact with the site team. If infiltration proves unviable, we will:

• Conduct a site walkover

• Identify alternative discharge solutions

• Ensure the most cost-effective drainage strategy for your project

Receive Your BRE365 Report

Following testing, you will receive a planning-compliant report, including:

• BRE365 infiltration rate (critical for design)

• Suitability for soakaways or other infiltration-based SuDS

• Professional drainage recommendations

How Is the Report Used?

Your BRE365 report can be used to:

• Support a SuDS report or Drainage Strategy for planning

• Discharge planning conditions related to drainage

• Enable engineers to proceed with detailed drainage design

What Our Clients Say

⭐ Sarah M., Andover

“Adam carried out our BRE365 infiltration test quickly and professionally. He explained everything clearly on site and made the whole process straightforward. The report came through promptly and helped us move forward with our planning application without delays.”

⭐ James T., Charlton Village

“Great service from Adam. He arrived on time, got straight to work, and kept us informed throughout the testing. It was reassuring to have someone knowledgeable on site who could answer our questions. Highly recommend Nimbus for anyone needing infiltration testing.”

⭐ Rebecca L., Anna Valley

“We needed a BRE365 test urgently for our planning application, and Adam was brilliant. Efficient, friendly, and clearly experienced. He even talked us through potential next steps depending on the results. Excellent service.”

Need a BRE365 Infiltration Test?

If you’re planning a development and need a fast, reliable, and cost-effective BRE365 infiltration test, Nimbus Engineering is here to help.

👉 Contact us today to discuss your site requirements and avoid unnecessary planning delays.