What is a Basement Impact Assessment?

What is a Basement Impact Assessment?

“If your proposed development includes a new or extended basement you may need to submit a Basement Impact Assessment, also known as a BIA.  This risk assessment report is tailored to assess the impact of the development on drainage, flooding, groundwater conditions, and structural stability.

A basement impact assessment typically evaluates the potential effects or consequences of constructing a basement or excavating below ground level in a particular area.

This assessment is important for several reasons:

  • Structural Integrity: It helps determine whether the proposed basement construction could affect the stability or integrity of existing structures nearby. Excavating near buildings or infrastructure can potentially compromise their foundations, leading to structural issues
  • Groundwater Management: Excavation can disrupt groundwater flow and affect local water tables. A basement impact assessment evaluates the potential impact on groundwater levels, drainage systems, and nearby water sources to ensure proper management of water during and after construction
  • Environmental Concerns: Construction activities can have environmental consequences such as soil erosion, habitat disturbance, and contamination of water sources. An assessment helps identify potential environmental risks and provides measures to mitigate them, ensuring compliance with environmental regulations
  • Risk Mitigation: It identifies potential risks associated with basement construction, such as soil instability, slope stability, and the presence of underground utilities. By assessing these risks beforehand, appropriate measures can be implemented to minimise the likelihood of accidents or damage during construction
  • Regulatory Compliance: Many Local Authorities require developers to conduct basement impact assessments as part of the planning permission process. These assessments help demonstrate compliance with building codes, zoning regulations, and environmental laws

What is a Basement Impact Assessment and Why Would I need One?

Risk Assessment to Support Planning Permission

The BIA is an evaluation that is completed to understand the potential effects or consequences of excavating below ground level or constructing or extending a basement.

A BIA is a  a comprehensive review that scrutinises a proposed basement development and its potential effects on the site and its immediate vicinity. Basement projects, though promising, are not devoid of concerns. Issues such as groundwater level disturbances, surface water and sewerage flooding risks, and the potential loss of local environmental features can be of great concern. Hence, ensuring the appropriateness of proposed basement developments and adherence to building regulations, local authority planning permission and health & Safety policies is imperative.

The starting point is a screening desk top study.

This is a preliminary risk assessment report for a development site, conducted by an experienced practitioner. By compiling available information in relation to a site’s environmental, geological, hydrogeological, hydrological setting the basement impact risk can be established and if required  a cost-effective and focussed site investigation will be developed.

If the Desk Study highlights the possibility of risk or impact from the basement excavation further investigation would be needed depending on the risks highlighted.

At Earth Environmental & Geotechnical we provide a comprehensive range of  risk assessments and site investigation services.

If you are planning a new development and need geotechnical services contact us now to discuss Geotechnical and Geoenvironmental Services throughout the UK.

Basement Impact Assessment Hackney London

Basement Impact Assessments are Essential for Planning Permission in some parts of the UK if you are development includes a new or extended basement.

Basement Impact Assessment & Surface Water Drainage Design

What is included in a Basement Impact Assessment?

  • Desk Top Screening Assessment
  • Preliminary Technical Report
  • Desk Top study of groundwater and surface water flow
  • Identification of potential risks and site investigations required

For a fixed price of £995 +VAT Earth Environmental & Geotechnical Ltd. provides the information and recommendations of any further investigations which would be required to support your planning application so your basement development can progress safely.

The price is based on an average size, complexity, and location. If your development has additional complexities then one of our team will discuss the options and the most pragmatic strategy to progress.


What is a Basement Impact Risk Assessment and When Would I Need One?

A BIA reviews a proposed basement development and its impacts on the site and local area.
Basement development can raise some concerns – there is a potential for development to cause issues with groundwater levels and surface water/sewerage flooding, as well as the possibility of a loss of local environmental features such as gardens, trees, and biodiversity.

You will need to ensure your proposed basement development is appropriate and that policies have been met where required.

Whilst not all Local Planning Authorities require a BIA as part of the planning application process many LA’s do. It should be noted that there is no national guidance on how to produce a BIA, so you will need to review your Local Authority’s guidance closely. Earth Environmental & Geotechnical Ltd. can assist you with this. Each Local Authority will have its own requirements for the assessment, at Earth Environmental & Geotechnical Ltd. we have extensive knowledge of providing basement risk assessments in line with local authority guidelines around the UK, including extensive projects in Hammersmith and Fulham, Kensington and Chelsea, Westminster, Camden, Haringey to name a few.

Why Choose Earth Environmental & Geotechnical Ltd?

  • Expertise: With years of industry experience and a team of seasoned professionals, we possess the geotechnical & geoenvironmental skills required
  • Customised Solutions: We understand that every property and development site is unique, which is why we offer  solutions tailored to your development sites specific needs and circumstances
  • Compliance: Our adherence to regulatory standards and best practices ensures that your project remains in full compliance with legal requirements and industry regulations.
  • Commitment to Excellence: From the initial consultation to project completion, we prioritise excellence in every aspect of our service delivery, striving to exceed expectations at every turn

Earth Environmental & Geotechnical Ltd delivers comprehensive solutions that prioritise safety, efficiency, and compliance. With our expertise in basement impact risk assessments and site investigations, we have the skills and knowledge your development site requires.

Contact us today to learn more about how we can support your project’s success.

More About Earth Environmental & Geotechnical Ltd.

We have worked on a huge array of your sites, from former gasworks, Victorian reservoirs, sewage works, battery storage facilities, renewable energy projects, asbestos factories, electricity sub-stations, collieries, fuel retailing stations, airports, abattoirs, quarries, landfills, etc.

Our services have been used to assist in securing planning permission and for the planning and design of new retail stores, housing projects, renewable energy, windfarms solar projects, landfills, quarries, and the restoration of numerous brownfield sites.

We deliver, and take pride in, providing cost effective and pragmatic geotechnical and environmental solutions from our 12 offices in Bath, Cardiff, Edinburgh, Inverness,  Stockport, Maidstone, Reading , Exeter, Southampton, Norwich, Birmingham, and Wilton.

All of our offices are run by highly experienced Directors, backed by degree-qualified staff.

Contact Us now to discuss your project