BRE 365 Infiltration Testing & Soakaway Testing Services UK

Professional BRE 365 Infiltration Tests from £850 + VAT

Need a BRE 365 infiltration test for a planning application, drainage design or soakaway proposal? We can help.

Evolution Safety Solutions Ltd provides professional BRE 365 infiltration testing for homeowners, property developers, architects, drainage consultants and construction professionals throughout the UK.

Whether you are developing a new property, extending an existing building or responding to a planning condition, reliable ground infiltration data can be essential to your drainage proposal.

Our service helps establish how quickly water infiltrates into the ground, providing evidence to support the assessment and design of soakaways and infiltration-based Sustainable Drainage Systems (SuDS).

Our BRE 365 infiltration testing service starts from £850 + VAT for one hand-excavated trial pit in suitable ground conditions, with water supplied by the client.

We provide clear test results, supporting calculations and a professional report for your drainage designer or planning submission.

Get your drainage investigation moving.

Call 03333 399 037 or request your BRE 365 infiltration test quotation.

What Is a BRE 365 Infiltration Test?

A BRE 365 infiltration test measures the rate at which water infiltrates into the surrounding ground.

The test follows the principles of BRE Digest 365 – Soakaway Design, which provides a recognised methodology for investigating ground infiltration characteristics and supporting soakaway design.

During the investigation, a trial pit is excavated at an appropriate location and depth. Water is introduced into the pit, and the rate at which the water level falls is recorded.

The resulting measurements allow an infiltration coefficient to be calculated, normally expressed in metres per second (m/s).

This information helps drainage designers establish whether infiltration drainage may be feasible and informs the design of suitable systems.

Importantly, the test does not guarantee that a soakaway will be viable. Poorly draining soils, groundwater conditions or other site constraints may mean that alternative drainage solutions are necessary.

Our role is to provide reliable site-specific testing and clearly documented results.

Why Might You Need a BRE 365 Infiltration Test?

Planning authorities, drainage engineers and other approving bodies may request infiltration testing where a development proposes to discharge surface water into the ground.

Without suitable ground data, it can be difficult to demonstrate whether a proposed soakaway will perform as intended.

You may require testing for:

• New residential developments.
• Single-house developments and self-build projects.
• Residential extensions and additional hardstanding.
• Commercial and industrial developments.
• Surface water drainage strategies.
• Sustainable Drainage Systems (SuDS).
• Planning condition discharge applications.
• Soakaway feasibility investigations.
• Drainage designs requiring measured infiltration rates.
• Sites where previous drainage information is unavailable or insufficient.

The exact requirements depend on the development, local planning policies, drainage design and site conditions.

Has Your Planning Officer Requested an Infiltration Test?

If your planning condition, drainage consultant or local authority has requested BRE 365 testing, send us the relevant details.

We can review the proposed scope and arrange an appropriate site investigation.

Contact Evolution Safety Solutions to discuss your requirements.

BRE 365 Testing for Planning Applications and Drainage Design

Surface water management is an important consideration in development proposals.

Where infiltration drainage is proposed, the suitability of the ground must be investigated before a drainage designer can rely on an assumed infiltration rate.

BRE 365 testing provides measured information about the site’s infiltration characteristics.

The results may support:

Planning Applications

A professional infiltration test report can provide supporting evidence for a planning application where the proposed drainage solution relies on infiltration.

Discharge of Planning Conditions

Some planning permissions contain conditions requiring further drainage information before development proceeds.

Where infiltration testing is specified, our report can provide relevant evidence for the submission.

Soakaway Design Calculations

Drainage engineers use infiltration coefficients alongside design rainfall, contributing drainage areas, groundwater information and other parameters when sizing soakaways.

Sustainable Drainage Systems

Infiltration-based SuDS may help manage surface water runoff, subject to site suitability and applicable drainage requirements.

Our testing helps establish whether ground infiltration can be considered as part of the drainage strategy.

Building Regulations Supporting Information

Infiltration testing may also support drainage proposals being considered in connection with Building Regulations requirements.

However, acceptance of a drainage proposal remains subject to the relevant approving authority and the overall design.

What Does Our BRE 365 Infiltration Testing Service Include?

We provide a practical testing service with a clear scope and professional reporting.

1. Initial Site Information Review

Before attendance, we discuss the proposed development and the reason for testing.

Where available, we review relevant information such as:

• Site address and access arrangements.
• Proposed development details.
• Existing or proposed drainage layout.
• Planning conditions or drainage requirements.
• Proposed soakaway location.
• Available ground investigation information.
• Relevant site constraints.

This helps determine whether the requested test is suitable and what arrangements are required.

2. Trial Pit Excavation

For the standard hand-excavated service, our team excavates one trial pit in suitable, hand-diggable ground.

The standard allowance is for a pit up to approximately 1.2 metres deep, subject to safe excavation conditions and site suitability.

The appropriate dimensions and depth depend on the proposed drainage arrangements and the agreed scope.

If the ground contains significant obstructions, rock, concrete or other material that prevents safe hand excavation, mechanical excavation may be required.

Any additional excavation requirements will be discussed separately.

3. Water Infiltration Testing

Once the trial pit has been prepared, water is introduced to assess infiltration performance.

The testing procedure includes recording the water level over time and undertaking the necessary observations.

Pre-soaking and repeat test cycles are carried out as appropriate to the methodology and site conditions.

The test duration depends on the rate at which the water infiltrates into the surrounding ground.

Some soils drain relatively quickly. Others may require longer monitoring periods or may demonstrate very limited infiltration.

4. Infiltration Rate Calculations

Following testing, we review the measurements and calculate the relevant infiltration coefficient where the results permit.

This provides information that a drainage designer can use when assessing soakaway feasibility and developing the drainage design.

Where a meaningful infiltration coefficient cannot be established, the report will explain the observed conditions and relevant limitations.

5. Professional BRE 365 Infiltration Test Report

We prepare a written report documenting the investigation and its findings.

The report provides a record of the testing undertaken and the resulting information.

What Will You Receive?

Following completion of the agreed investigation, you will receive a professional BRE 365 infiltration test report.

Depending on the investigation and results, the report will include:

• Site identification and location information.
• Purpose and scope of the investigation.
• Trial pit location and dimensions.
• Description of the testing methodology.
• Relevant site and ground observations.
• Recorded water-level measurements.
• Test results and supporting calculations.
• Calculated infiltration coefficient, where obtainable.
• Photographic evidence.
• Relevant findings and limitations.

The report can be provided to your architect, drainage engineer, planning consultant or other relevant professional.

Please note: The service provides infiltration testing and reporting. Full drainage design, soakaway sizing, detailed construction drawings and planning submissions are not automatically included.

These services must be separately agreed where required.

How Much Does a BRE 365 Infiltration Test Cost?

Standard Hand-Excavated Infiltration Test – £850 + VAT

Our advertised standard service is £850 + VAT for one trial pit in suitable hand-diggable ground conditions.

The standard allowance is based on:

• One agreed trial pit location.
• Hand excavation to a maximum approximate depth of 1.2 metres, where safe and practicable.
• Suitable ground that can be excavated using hand tools.
• Water supplied by the client.
• Access to the test location.
• Agreed infiltration testing.
• Preparation of the test report.

The standard fee does not automatically include mechanical excavation, additional trial pits, specialist groundworks or repeat attendance.

Additional costs may apply where the site is outside the standard scope, including travel requirements where applicable.

What If You Already Have a Trial Pit Excavated?

If you can arrange a suitable trial pit and provide the necessary water, we can review whether a testing-only arrangement is appropriate.

This may reduce the excavation work required from our team.

Please contact us with the proposed pit dimensions, depth, location and site photographs so that we can confirm suitability and provide a quotation.

What If the Ground Cannot Be Excavated by Hand?

Some ground conditions make hand excavation impractical or unsafe.

Examples include:

• Rock or very hard ground.
• Buried concrete or substantial obstructions.
• Unstable excavations.
• Significant groundwater ingress.
• Restricted or unsuitable access.
• Unexpected buried services.

Where these conditions prevent the agreed work from proceeding, we will explain the issue and discuss the available options.

Additional excavation, alternative test arrangements or a return visit may involve further charges.

We will not automatically undertake additional chargeable work without discussing the revised requirements.

Need More Than One Trial Pit?

Larger developments or sites with varying ground conditions may require multiple infiltration test locations.

We can provide a quotation based on the number of pits, site layout, access requirements and proposed drainage arrangements.

For a quotation, call 03333 399 037 or send us your site details.

What Do We Need Before Booking Your Test?

To provide an accurate quotation and arrange attendance, please supply the following information where available:

1. Site address and postcode – so we can establish the location and travel requirements.
2. Purpose of the test – for example, a planning condition, new development or drainage design.
3. Proposed soakaway location – ideally shown on a site plan.
4. Required test depth – if specified by your drainage engineer or planning consultant.
5. Number of trial pits – if already established.
6. Site photographs – showing access, ground conditions and the proposed testing area.
7. Water availability – confirmation that sufficient water can be provided.
8. Excavation arrangements – whether the pit is to be hand-excavated, prepared by the client or mechanically excavated.
9. Relevant documents – planning conditions, drainage drawings or previous investigation reports.

Don’t worry if you don’t have everything available.

Our team can explain which information is necessary before confirming the testing arrangements.

How Our BRE 365 Testing Service Works

Step 1 – Contact Our Team

Tell us about your project, the site location and why infiltration testing is required.

You can contact us by telephone or through our website.

Step 2 – We Review the Requirements

We consider the proposed testing location, excavation arrangements, water supply and any relevant planning or drainage requirements.

Step 3 – Receive Your Quotation

We confirm the agreed scope, fee and any additional arrangements needed.

Step 4 – Arrange Site Attendance

We schedule the investigation for a suitable date and confirm site access and preparation requirements.

Step 5 – Undertake the Infiltration Test

Our team attends the site, completes the agreed investigation and records the relevant observations and measurements.

Step 6 – Receive Your Report

We review the findings, undertake the relevant calculations and prepare the report.

You can then pass the report to your drainage consultant, architect or planning adviser.

REQUEST YOUR BRE 365 INFILTRATION TEST

Who Do We Work With?

Homeowners and Self-Builders

If you need an infiltration test for a new home, extension or planning condition, we can help establish the appropriate testing arrangements.

Property Developers

We support residential and commercial development projects requiring site-specific infiltration data.

Architects and Planning Consultants

Our reports provide relevant technical information to support drainage-related submissions and design coordination.

Drainage Engineers and Designers

We undertake field testing to provide measured infiltration data for drainage assessment and soakaway design.

Groundworks and Construction Contractors

We can coordinate testing around site access, excavation arrangements and construction programmes.

Why Choose Evolution Safety Solutions?

Professional, Practical Site Investigations

We understand that clients need reliable information to progress their projects.

Our service focuses on obtaining relevant field measurements and presenting the results clearly.

Clear Scope and Transparent Pricing

Our standard fee is explained in advance, together with the assumptions and limitations that apply.

Where additional work is necessary, we discuss the requirements before proceeding.

UK-Wide Service

Based in South Wales, Evolution Safety Solutions supports clients throughout the UK.

Travel, access and site-specific arrangements are confirmed as part of the quotation.

Professional Reporting

We provide structured reports that document the investigation, measurements, calculations and relevant findings.

Wider Environmental and Development Consultancy

Evolution Safety Solutions also provides environmental consultancy and development-support services.

Where a project requires additional technical support, our team can discuss the relevant requirements and whether they fall within our services.

Frequently Asked Questions About BRE 365 Infiltration Testing

What is the purpose of a BRE 365 infiltration test?

The test establishes how quickly water infiltrates into the ground at the investigated location.

The results help drainage designers assess whether infiltration drainage may be suitable and provide information for soakaway design.

Is a BRE 365 test required for planning permission?

Not every development requires one.

However, planning authorities or drainage advisers may request infiltration testing where soakaways or infiltration-based drainage systems are proposed.

The need for testing depends on the project and applicable requirements.

How much does a BRE 365 infiltration test cost?

Our standard hand-excavated service starts from £850 + VAT for one trial pit in suitable ground conditions, with water supplied by the client.

Additional requirements are quoted separately.

How deep does the trial pit need to be?

The appropriate depth depends on the proposed drainage design and site conditions.

Our standard hand-excavated allowance is up to approximately 1.2 metres, subject to safe working conditions.

Deeper investigations or alternative excavation arrangements require separate consideration.

Do I need to supply water?

Yes. Our standard advertised service assumes the client supplies sufficient water for the testing.

If this is not possible, contact us before booking to discuss the options.

Can I excavate the trial pit myself?

Potentially, yes.

However, the pit must be suitable for the required methodology, location and safe access arrangements.

Please confirm the proposed dimensions and excavation arrangements before undertaking the work.

What happens if the ground does not drain?

Poor infiltration is itself an important finding.

Where the ground does not infiltrate sufficiently, the results may indicate that a conventional soakaway is unsuitable.

Your drainage designer can then consider alternative drainage arrangements.

Does the test guarantee that I can install a soakaway?

No.

The results are one part of the drainage design process.

Groundwater conditions, separation distances, site constraints, drainage design and other considerations must also be addressed.

How long does a BRE 365 infiltration test take?

The duration depends on the ground conditions and infiltration performance.

Testing can take several hours, although slow-draining ground or more complex requirements may necessitate additional time or attendance.

Will I receive a report for my planning application?

Yes. We provide a professional report recording the agreed investigation and its findings.

However, acceptance of the report and any associated drainage proposal is determined by the relevant authority.

Does the price include a soakaway design?

No. The standard service covers the agreed infiltration investigation and report.

Full drainage design, soakaway sizing and construction drawings are separate services.

Can you test more than one location?

Yes. We can discuss multiple trial pits where required.

The number and location of tests should reflect the development and the requirements of the drainage designer or approving authority.

Do you provide testing throughout the UK?

Yes. We offer UK-wide coverage, subject to site location, availability and agreed travel arrangements.

Book Your BRE 365 Infiltration Test Today

Reliable Ground Infiltration Data for Your Drainage Project

Whether you need to support a planning application, discharge a drainage condition or provide infiltration data to your engineer, Evolution Safety Solutions can help.

Our BRE 365 infiltration testing service provides practical site investigation and clear professional reporting.

Standard hand-excavated testing from £850 + VAT.

Get in touch with our team to discuss your site, testing requirements and availability.

Call 03333 399 037

ENQUIRE NOW – BOOK YOUR BRE 365 INFILTRATION TEST

Evolution Safety Solutions Ltd – Professional BRE 365 Infiltration Testing, Soakaway Testing and Environmental Consultancy Across the UK.