Unlocking brownfield sites through digital design and offsite construction

One of the most pressing current issues in the UK is the housing crisis. 275,000 homes a year are needed and there are a lot of questions on where these will be built. The Campaign for the Protection of Rural England (CPRE), recently published their report, State of Brownfield 2018, highlighting that there is sufficient suitable brownfield land currently available for more than 1 million homes. In January 2018, the new Ministry for Housing, Communities and Local Government announced that 310 local authorities had published brownfield registers identifying 26,000 hectares of brownfield land, and the CPRE have shown that this can be extrapolated further for unpublished registers.

We are also seeing regional plans taking a similar approach. The recent Draft New London Plan also backs development of brownfield land and intensification of the suburbs of London, through boroughs making proactive use of brownfield registers to increase planning certainty for those wishing to build new homes.

It can be easily recognised that we should not be sacrificing greenfield land for development when we are not maximising the potential of existing brownfield sites. Arguably, we still need to have some grown-up conversations about land that is currently designated green-belt that clearly does not provide the benefits. However, until such a time we must make best use of the land that is available and not up for debate.

So why are we not already making the most of this abundance of brownfield land? There are many challenges and constraints that can be imposed by a site and its previous uses. These can include lack of site records, contamination, obstructions in the ground, historic structures, archaeological remains, existing site infrastructure and utilities that need to remain or be rerouted, interfaces with adjacent properties and limited access, to name just a few! It is no surprise that these sites have been given a wide berth, when proving viability can be such a challenge. This is where the latest innovations in digital design and offsite construction can assist.

Historically, construction has been slow to innovate compared to other industries, as we continue to design and build with the same approaches that have been used for generations. The fact is that the world has been going through a digital revolution and we as an industry need to be embracing it to a far greater extent than we have to date. A digital design-led approach can be key to unlocking brownfield sites and maximising potential, through making use of parametric tools to create generative building forms and evaluate their performance against key constraints.

Bringing this engineering input to the initial stages of a project to inform the design can maximise the opportunities and increase the viability of a development, which can be especially critical for a constrained brownfield site. We are developing suites of tools that deliver greater efficiency throughout the whole design process, whether from the initial masterplanning and massing stages to detailed panelisation to minimise wastage. When combined with BIM the opportunities are endless.

When integrating these new approaches with modern methods of construction there will be combined benefits. We have seen offsite construction coming to the forefront of public and industry consciousness, with the political and media attention following the likes of Mark Farmer’s review, “Modernise or Die”, and the Housing White Paper. The advantages are clear, especially so for constrained brownfield sites. Lighter weight construction (such as cross-laminated timber or light-gauge volumetric steel pods) requires smaller foundation solutions with less intrusive groundworks, minimising the risks in the ground. Constructing offsite, whether fully modular or taking a “kit of parts approach”, can minimise transportation to sites that may have challenging access as well as simplifying the onsite logistics. The benefits of offsite can be ideal for overcoming the obstacles and constraints that brownfield land throws up.

To meet our ambitious housing targets, the large housebuilders cannot work alone. Indeed, a large proportion of brownfield sites will be too small for many of the larger housebuilders, so we need to make these sites more attractive to small and medium sized developers and contractors, or even “self-builds”. New technological tools, along with a number of the emerging offsite systems, could be the perfect solution to tip viability in the right direction, encouraging the development of brownfield land. Additional funding that may arrive via Homes England or other routes would also certainly help.

As an industry we really are on the verge of a huge shift in approach that, if we chose to embrace it, could bring massive benefits. Adopting modern and innovative approaches to both design and construction will help unlock the vital community resource that brownfield sites offer.