How to optimise the pre-construction period

13th January 2022

We examine how the pre-construction period can be optimised to achieve significant cost and time efficiencies

The pre-construction period is an important time in the business of buildings. It’s that crucial time prior to starting to work on the physical building that allows us to ratify the design rationale, complete any designs that we have taken on and coordinate design decisions between the various disciplines involved. It’s the opportunity to consider decisions that might otherwise be made in a more pressurised environment on site and avoid realising too late in the process that things need changing. It could mitigate modifications to things like ductwork or pipework, which are quite rigid materials.

But there are a few different schools of thought as to how long the pre-construction period should be. Sometimes with a construction period of 30 weeks, we’ll be given 8 weeks for pre-construction. But there is an argument to be made for rethinking those proportions and extending the pre-construction period. We need to overhaul the preconception that the project is not moving forward just because people aren’t on site.

A longer pre-con period can, in fact, bring with it various benefits from a longer time to coordinate tasks and disciplines to capturing change in a time efficient and cost saving manner. If a project is run in this way, it could contribute to cutting down on the scope creep which is usually 10-15%. The longer time that you have to validate, investigate and ratify decisions, the less the risk of scope creep. After all, it’s the end date and the cost that matters and we’re incentivised to keep within budget. The more time the consultants give us to de-risk things, the better and that includes our supply chain: being able to de-risk things downstream as well.

A longer pre-construction period gives more time to really sequence and plan the works out. For a particular project we completed earlier this year, the pre-construction period was much longer, driven by base build delays and the impact of Covid-19. In that pre con period, we are able to look at how the heating, cooling and electrics, as well as the more visible architectural elements are sequenced, designed and signed off. We had the luxury of being able to coordinate and design everything before it reached the site. We could pass the services through the walls and correlate that with the architectural elements, which can often be quite an ad-hoc process on site. But in this instance because we’d spent time considering how to do that in the pre-con period, we could keep things very efficient If there are delays with the base build or with other contractors, we can then take more time in pre-con, avoiding overlap and ultimately control and manage the process better. Given the current high demand and short supply of certain building materials such as plasterboard, any potential waiting time can also be spent ratifying, finalising and de-risking things, helping to ease this bottleneck in the supply chain

Even with innovations down the decades from CAD to BIM, it’s impossible to completely eliminate inefficiencies but making the most of the pre-con time you have available can help. As well as architectural elements, things like partitioning and joinery can be better coordinated, the same goes for lighting, ventilation grills, fire alarms and sprinklers. Sequencing and programming of a construction project is so key because when you lose that sequence, that’s when things can start to go wrong. It gives you the opportunity to look at what might be the most efficient order in which to build elements such as the services, the walls, floors, ceilings and lighting. This aligns with our overall goal at BW of Defect Free at Practical Completion (DF@PC).

That’s why we, at BW, believe that whatever the pre-con period it should be optimised to its full potential. There can be a tendency to carry on doing things in the traditional way because that’s the way they’ve always been done but as we’ve seen with other industries such as car manufacturing, huge inroads have been made in terms of process and cost efficiencies. The subcontractor, the contractor and the consultant are all on the same side in terms of saving money and building a better project for the client so the more we can do within the pre-con period to achieve that, the better!