Navigating historical structures to deliver construction elements with minimal tolerances.

The Kitchener Barracks project involved the redevelopment of a historic military site in Chatham, Kent. Providing over 300 much needed new homes, the project is one of the largest residential schemes to adopt modular construction processes in the UK. K5 Construction was engaged under sub-contract to handle the strategic approach for the delivery of the first phase of the project and deliver enabling works, cut & fill, drainage & infrastructure, RC works, house foundations, hard standings and roads.

We were pleased to be engaged to provide key services to our clients on what was a complex site on which to build both technically and logistically. During the construction phase, we fully managed our project works and coordinated site meetings with appointed consultants, architects, engineers, sub-contractors, local authorities and third-party representatives.

Some buildings and structures were protected and listed, and consideration needed to be given to these elements in terms of the preservation and protection treatments. The site has WW2 service tunnels originally running from the River Medway, west under the barracks and subsequently turning out of the north boundary. These tunnels required inspection and remediation and were under the care and interest of Historic England. The presence of the tunnels dramatically affected the cut and fill elements along with the required ground remediation works. In addition to this, we were working with the Archaeological Team to remove historic foundations section by section to allow for the recording of the historic elements.

It was clear that a careful design approach and logistical management would be required if the project were to be delivered to the client’s requirements and comply with the expectation of the local authority and conservation organisations. The primary goal was to understand the design intent and our building engineers worked closely with the Architects and Structural Engineers to prove constructability and value engineer the construction elements. Our direct technical input reduced the projected costs of the retainment, remediation, and foundations by over £750,000. The costs associated with the lower-level car park, integral frame arrangement and podium slab were reduced by a significant £1.2M.

The tolerances across the site were as low as 3mm on the horizontal plain and reduced vertical tolerances that would allow for the coupling of services including storm and foul during the vertical installation of the modules. During the pre-construction period, the K5 team appraised the phasing, logistical and traffic management plans to ensure that we were able to accommodate the phased delivery of the modular housing elements. Effective programming was critical to the delivery and it would mean that K5 would be required to not only deliver the construction requirement but understand the logistical and environmental impacts along with the project risks.