Background

Following the demise of the Masters chain, our client wanted to convert part of an existing warehouse structure into a multi-brand car dealership and workshop for a new tenant.

As the budget was very tight, their primary objective was to maximise the re-use of the existing structure in order to reduce dismantling, replacement and removal costs. 

Challenge

Re-using the existing structure posed difficulties as warehouse buildings are typically designed for economy and are often very flexible with little residual capacity. A dealership is much more heavily loaded and has many brittle finishes and glazing which cannot tolerate much movement, meaning much of the existing structure would be incompatible with the new use.

The redevelopment required the end bracing wall of the main warehouse to be moved 16m while the main warehouse roof remained intact. This posed two challenges; it would render the entire structure completely unstable during construction and required access that was not available with the roof structure and sheeting in the way. 

Solution

We remodelled the entire existing structure to determine the key structural elements required to support the new loads. We then explored ways of strengthening the non-compliant elements to avoid disassembling the entire structure just to replace an element. Our thorough approach enabled over 55% of the roof to be re-used rather than replaced, resulting in substantial savings in labour and material costs.

By leveraging BIM, we were able to accurately identify which removed members could be reused elsewhere on the project, thereby reducing both the amount of new steel required and the transport costs to site.

Our modelling and analysis of the existing building provided a clear understanding of how the structure would behave without the bracing wall. We then developed a temporary bracing system which stabilised the entire building while the bracing wall was relocated safely.

We liaised with the steel erectors to develop a design methodology to replace the new wall using small parts which could be erected inside the existing building. This allowed construction to happen underneath the existing roof, without needing a crane, which avoided removing 1700m² of the roof.

By maximising the reuse of existing material and limiting the amount of structure that needed to be dismantled, we reduced project costs by over $500k.