The recent launch of an open-source app to facilitate early planning for using offsite systems is a thoroughly modern solution that should help drive a modern way of working 

Mark Farmer 2017 BW

Last month in London a new digital platform was launched that could mark a real milestone in evolving how we design and plan residential buildings. Prism is a web-based, open-source application that helps developers and their teams consider the opportunities for using pre-manufactured building systems at the very earliest point in the development cycle. It is the first openly available city-wide technology application of its kind in the world.

The application has been developed in a partnership between my business, Cast and the tech-led design consultancy, Bryden Wood. It has been sponsored by the mayor of London, as part of his London Housing Strategy commitment to promote precision manufactured housing. 

This can ultimately create the beginnings of an online marketplace that automates and connects workflows from design and rules-based planning to costing and procurement to manufacturing

Both Cast and Bryden Wood recognised that this was an opportunity to drive a digital aid that was user friendly and intuitive and encouraged people to approach the front end of the development process differently. We know that a bespoke, design-led process leads to much of the opportunity for manufacturing standardisation at an elemental or building “chassis” level being lost. Design for manufacture and assembly (DfMA) is only optimised when it is considered early. All too often, consideration of modern methods of construction (MMC) comes too late for it to be effectively incorporated into a planning-stage design when key variables have become fixed.

What is notable about Prism is that it can be used by anyone, anywhere in the world, free of charge. Although it is focused on Greater London and has GIS mapping data loaded purely for the London, its functionality can be accessed by all. It is also symbolic that Prism was jointly funded alongside the mayor of London by four land-led developers and investors: Greystar, TfL, Legal & General and L&Q. This has not been developed as a sales tool for the offsite manufacturing sector but has been driven by a group of progressive property organisations who all know they have to commission homes differently if they are to achieve their own business plans.

There are two core component parts of Prism. Firstly, there is an open database for anyone with a scheme in London to upload their project and see how their key design and spatial metrics benchmark against a big dataset (all on an anonymised basis). We all know data is increasingly going to be a point of competitive advantage and having democratised, open data sets is going to be more common in the future. This platform looks to initiate that but will only be successful if the market engages. It needs everyone to participate and create what could be a powerful single version of the truth for better understanding what we are actually building and the trends and patterns that result.

The second core functionality of the tool is DfMA optimisation. Prism includes an intelligent design configurator, linked to the London Housing Design Guide, that enables any site in London to be selected and different building shapes and forms to be tested, with an instant overlay of the alignment potential to different building systems. This has been initially launched with only Category 1 and Category 2 MMC system parameters (volumetric and panelised structural systems) but the potential is for this to evolve across the wider spectrum of residential MMC. 

We also see the design configurator having more available building typologies added in the future. It is important to note that this app does not replace architects, it augments and liberates them to spend more time advising their clients on value-add issues relating to aesthetics, context, public realm and placemaking. 

The app can also have much more core functionality added to it in the future. This might include auto-calculation of pre-manufactured value for differently configured design options.

It could also expand to include consideration of the wider categories of residential MMC as set out in the new government definition framework, going beyond the Category 1 and 2 structural building systems that it’s currently been scoped to focus on.

Prism can also form the basis of a maturing online functionality. Through future plug-ins it can link to a digitalised planning environment as well the manufacturing supply chain. This can ultimately create the beginnings of an online marketplace that automates and connects workflows from design and rules-based planning to costing and procurement to manufacturing. This could start to overcome the barriers the market faces in terms of transactional procurement, supply chain immaturity and lack of commercial understanding of MMC. 

The overarching intent of Prism is to start influencing behaviours and attitudes and to get people thinking differently earlier. We also see Prism acting as an educational tool, building on Minecraft principles but more rooted in the real world and with real parameters. As a trustee of built environment educational charity Mobie, I will be exploring routes to how it can be used on our school, college and university programmes. I have always said that industry change will be accelerated by leadership from clients and the key decisions they make at the very outset of a development. This app offers the opportunity to influence that process at a scale not attempted before. I urge you all to engage with it, provide feedback and influence how you want it to further evolve.

Prism is available at

Mark Farmer is chief executive of consultant Cast and author of Modernise or Die