Written by The SiteSolve Team on 26/03/2020

Case Study: Transport For London

The Housing Strategy Team, part of Transport for London (TfL) Commercial Development, is building a case for land associated with transport infrastructure that could be released for development in key locations in London. As part of their case to government, TfL want to understand the potential number of homes they can unlock through the investment of infrastructure routes. Ramboll was commissioned to use SiteSolve to undertake a mass land study to evaluate the viability of over 2000 plots of land. The outcome of the study enabled TfL to understand the viability of all the sites and prioritise the land with greatest potential. This gave them important insight into a number of key metrics, including cost, value and the number of units that could be achieved over these sites to help support their strategic decision making.

SiteSolve’s generative design engine enables thousands of massing options to be tested for each site to identify an optimal arrangement for each one that considered the actual plot geometry, access and planning constraints. The algorithm targeted the desired apartment mix by packing apartment types around cores sized and located based on real engineering rule sets and insight.

For every single site, SiteSolve gave a detailed breakdown outlining the likely number of achievable units, the target mix achieved as well as a cost and value breakdown. Flags highlighted key risks associated with the site, such as topological slope steepness or contaminated land risk, to give an understanding into how different restrictions and constraints could affect the potential to build out each plot of land.

Transport For London

Transport For London

By engaging and collaborating with external parties, Ramboll was able to embed the planning, value and cost information to create a data-driven optimisation approach. Urban Intelligence provided planning information and site boundaries which SiteSolve could automatically extract and use to generate massing within the planning limits. The live link with Turner and Townsend’s cost API, meant each option could be costed with real information that considered the site-specific constraints, such as track adjacency or flood risk. Finally SiteSolve could also calculate the value of every option based off local market data supplied by Hometrack, while Hatch provided data that allowed likely value uplift up to 30 years into the future to be considered.  By acting as a hub into which all this data was fed and incorporated into the massing generation process, SiteSolve developed credible solutions which were optimised for true return on investment.

Transport For London

This innovative approach resulted in greater certainty than traditional policy-based density regulation methods in determining the number of apartments achievable on each site as it enabled a value-based, data-driven approach. It gave a higher level of informative detail as well as a visual sense of the capacity of every plot giving TfL greater understanding of the risks and opportunities over the whole portfolio of sites. By utilising a cloud-based system thousands of sites were analysed in parallel, this mass land viability study could be undertaken in only a matter of hours, a fraction of the time it would take a human designer or planner to look at just one.

Using SiteSolve to rapidly evaluate this large land portfolio ensured no site was overlooked, and every site was optimised to maximise its potential. Furthermore, the more accurate analysis that SiteSolve provided will help de-risk the development of marginal land and increase land use efficiency. This study is a crucial piece of work to identify opportunities for unlocking land for affordable homes, alongside better journeys.

Transport For London


“Sitesolve has been a key delivery partner supporting us on a first-of-a-kind pilot project to analyse and appraise a large volume of potential development sites in London. Sitesolve is a powerful tool driven by a very experienced team that enable us to gain an in-depth understanding of the portfolio, providing excellent results in a short amount of time and cost-efficient way”

Candice Lemaitre - Transport For London - Commercial development Innovation Lead


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