Croft has extensive experience working with both clients and professions on Basement Impact Assessment projects of varying scale. For information on other Boroughs, please speak to one of the team today on 020 8684 4744.

Basement Impact Assessments

This report looks at how the construction of a basement affects the ground to the local area and in turn the neighbours.

The Hydrogeology

The councils want to confirm that when you excavate a sizeable hole that its affects have been considered. A sensible approach really. Different boroughs have different criteria and levels of information, but they mainly want to know:

  • Will the basement cause flooding?
  • Will the basement affect water flows around the area?
  • Will the basement affect neighbouring properties?
  • Will the basement affect any historic structures?
  • Will it affect the local highway, or infrastructure (Rail or underground)?
  • Has a trained professional looked at the project and considered the pitfalls?
  • Ensuring the basement is inspected by a trained professional during the works

Ground Movement Assessment

Any excavation in the ground distributes stresses. The ground movement assessment looks to gauge expected movement to strains in local building. This is then given a Burland Scale reference. In line with the CIRIA C820 report Croft have developed their own software for movement of small basements in clay.


The study of water flow through the ground is Hydrogeology. Croft look at how water flow may be affect around the new basement. 1 Basement is of little effect; Constructing all the basements in a terrace will create a dam forcing water to flow into different areas.

Croft BIA Includes

  • Site inspection
  • Soil Investigation
  • Hydrogeology and Geology Statements
  • Ground Movement Assessments
  • Structural Design
  • Structural Drawings
  • Temporary Works
  • Method Statement
  • Surface Water , SUDS and FRA
Our Projects

Delivering projects at varying scale

We understand that a property is a large investment, which is why we work on an ethos of providing a personal approach to all projects. Whether small or large, when appointing Croft you will be assigned your own engineer to personally lead through your construction process every step of the way. We have the resources to deliver projects within a framework that suits you.

Croft Structural + Civil overseeing construction on site

Providing a personal approach to projects