Delivering significant construction cost savings

The 2015–20 capital programme represented a significant opportunity for us. The traditional challenges around time and cost demanded disruptive solutions to confront the normal ways of working. Conventional on-site manufacturing can be noisy and disruptive for our customers and neighbours, and it can be expensive to remove the inherent safety risks that go with being on busy construction sites.

Designing and building off-site in a factory reduces the disruption for customers and lessens the on-site safety risk. Design for manufacture and assembly (DfMA) involves the digital design and prefabrication of a significant proportion of a project offsite. Working in a DfMA and Building Information Modelling (BIM) environment allows standard supply chain products to be embedded within the BIM model and then ordered and built within the supply chain. We have seen this with electrical kiosk design, procurement and assembly, where the risk for rework and on-site modifications was significantly reduced as a result of this new approach.

Strategic success

Having already made a significant return on investment, the DfMA initiative has been a strategic success. It started as an innovation project, but now it is the accepted way of working within our business and our supply chain.

As a result, we have already delivered over £5.2 million in direct construction cost savings, nearly 11,500 site days, as well as innumerable productivity and health and safety benefits.

The default programme approach to DfMA has driven a culture within our partners and their supply chain, which will benefit capital programmes in the future. We will see more and more standard products being developed by our supply chain, which will increase the proportion of our construction projects going forward that use DfMA.

Jackson's Edge service reservoir

We appointed a construction company to replace an existing service reservoir that was over 100 years old with an expired asset life. The new asset consists of two reservoir compartments, the first of which was to be commissioned prior to commencing construction of the second, thereby allowing the existing asset to be demolished whilst maintaining supply.

Due to its proximity to residential properties, and in order to deliver the scheme as efficiently as possible, a DfMA approach was selected using a system of modular pre-cast wall panels. DFMA led to a significant reduction in the timescale of the overall programme (8-10 weeks) as well as a reduced number of people on site.

Further efficiencies were achieved through the use of BIM and the coordination of civil, structural and mechanical discipline models, helping to ensure the design was right first time. The project was completed in October 2016.