Why detailed Site Investigations are Important

In this article, we look at “Why detailed Site Investigations are so Important for Correct Foundation Designs and why it is important to know exactly what you are building on.

In a significant development near Cambridge, the demolition process has commenced for 36 homes due to foundational concerns. The development site in Cambridge has plans to develop up to 2,500 new, high-quality homes, but after just 90 new homes were built 36 will have to be removed after the developer found faults in their construction. A further 47 plots will have remedial work to address the structural concerns. This decision comes as a precautionary measure to ensure the safety and stability of the affected properties.

The decision to demolish these homes stems from identified issues with their foundations, which were deemed to pose potential risks to residents. The homes in question, located in the vicinity of Cambridge, were constructed on land with complex soil conditions, leading to instability concerns. This extensive development is being completed in phases. Following the discovery of issues with the foundation design of some of the houses in the second phase, a review of the foundation design was commissioned.

It was found that the foundation and ground floor slab design is different between the two phases of development. It was also noted the building control inspector on the development, the NHBC, required heave precautions to be deployed for trench fill foundations where the foundations are deeper than 1.5m depth unless the NHBC is satisfied that the soil is not desiccated.