New Prisons Programme

Our environmental engineers are conducting ground investigations (GIs) at potential sites, scoping each investigation, and tendering for all survey works. We are leveraging our experience from similar complex sites to ensure there are no surprises regarding the number of investigations required.

Our environmental engineers’ appointment covers several potential locations for the new prisons, with site development running simultaneously. From our past experience, we recognise that large, complex sites often require multiple phases of site investigation.

We have structured our GI work to align with the RIBA stages, planning for multiple phases. We also explained to the Ministry of Justice (MoJ) the advantages of a phased approach to site investigations and the need to cost potential risk items. This ensures our investigations are precisely tailored for each site, even when the ground conditions encountered differ from those anticipated during scoping.

During RIBA Stage 2, we conduct desk studies and scope site investigations on a grid basis to assess the risks and constraints at each site. These studies enable the entire design team to provide Stage 2 designs with informed assumptions, such as requirements for piling, cut and fill, or soakaway drainage. This establishes a reliable ground model for RIBA Stage 3. For example, our desk studies and investigations confirmed that conventional strip footings would be unsuitable for certain buildings, evaluated the suitability of soakaways for drainage, and provided an initial assessment of site contamination. The MoJ and their quantity surveyor benefit from our early risk assessments, which include requirement for remediation or more expensive foundation solutions; a reasonable assumption re costs of waste soil removal; and requirements for import of materials for cut and fill, as we have assessed underlying soils' suitability for reuse.

Our design team assist with scoping any second phases of GI works, which are specifically targeted to known needs. These have included deep boreholes for piles; correct testing for re-engineered fill; and contamination assessment of identified hazards or areas not initially accessible with original investigation solutions.

RIBA Stage 3 phase works, across various sites, is carried out by our teams and supply chain simultaneously: so we meet the tight timescales for each project. All of our fee proposals include remeasurable risk items within the cost, so the MOJ is aware of the maximum costs and approved these from the outset.