Building more homes, with the same skilled workforce, at similar cost.
The Advanced Industrialised Methods for the Construction of Homes (AIMCH) is an initiative led by Stuart Milne with SME Forster Roofing, Barratt Homes and L&Q to gather comparative cost data on using Modern Methods of Construction at scale on real housing sites, versus traditional methods. Meeting Government housing targets is currently limited by the availability of skilled workers, and so requires innovation in build methods. By comparing an industrialised approach alongside a traditional build, and greater collaborative working through the supply chain, the partnership was able to prove that over 70,000 more homes could be built each year with the same workforce across the UK. The new methods are also considerably safer for employees and show significant improvements in productivity, efficiency, speed and cost.
Innovation type: Digital, Manufacturing, Offsite, Process
Organisation type: Housebuilder, Social housing provider, Supply chain
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Lead, innovative constructor Stewart Milne and key supply chain SME Forster Roofing are working together to change the build process, with Barratt Homes (the UK’s largest housebuilder) and L&Q (the second biggest social housing provider in the UK). With the scale (35,000 homes per year) and diversity these companies bring, wider change to the housebuilding sector will be fast and robust.
The industry currently isn't building enough high-quality, high-performing affordable housing at scale to meet Government goals and customer needs. This is caused by a fragmented, risk-averse industry; an ageing workforce with no new skilled workers entering the industry; poor productivity and inefficiencies through the supply chain; and building costs remaining high. So unless things change, these partners can only commit to delivering around 10% of the 300,000 target homes each year.
By embracing improved digital systems, efficient scheduling and standardised supply chain processes throughout the build, more houses can go up in half the time and using the same skilled workforce. These improvements will make home construction more productive at scale, safer for workers, and ultimately better quality and more affordable for the end user. The goal of the project is to support the sector by delivering 120,000 homes for the same or less cost than traditional methods, and built 30% quicker.
The UK government's call to build 300,000 homes a year (an increase from 220,000) cannot be met with the skilled workforce we have currently. The ambition of this project - Advanced Industrialised Methods for the Construction of Homes (AIMCH) - is to transform how we build homes, solving this challenge for good. With robust comparative data the consortium can make the business case to industrialise the housing sector and position themselves as leaders in delivering what the UK needs.
Barratt Homes and L&Q needed firm data on the wider cost impacts of adopting a manufacturing approach to building homes. To do this they committed to trial a mixture of approaches on live, real-world sites, side by side with traditional methods to directly compare. The site data is being used to build a persuasive business case for using such approaches at scale in place of traditional block and brick.
The housebuilding sector has been unconvinced of the need to industrialise. Instead it has continued to build houses using traditional methods of construction, that can’t deliver on volume targets and continue to fall short of quality standards. This has been compounded with the demands being put on the existing workforce due to a growing skills shortages.
Over 30 homes have been built using advanced MMC systems, all with customers now living in them. The methods trialled on real sites alongside traditional block and brick construction employ process approaches common in manufacturing. Parts are prepared in factories to high standards then assembled on-site in a schedule that maximises the time of the skilled labour. An example is that roof tiling is done on the ground and then the roof system lifted into place, a first for Barratt Homes. This limits the use and cost of scaffolding; the inside fit can continue while the outside brick layer is done without scaffolding getting in the way; it is significantly safer for site workers as they are not working at height; and the building can be watertight in a day. Building a house in parts brings quality improvements but also increased productivity - similar hours are logged, but done to more efficient scheduling in parallel with each other, and the skilled workforce are only asked to do what they are good at. AIMCH is exploring how design standardisation (keeping key dimensions the same across different house types) can also deliver greater volume with configurability, so more homes can be built using an industrialised approach; similar to the car industry. Monitoring of all processes in the project is revealing where non-value-add activities can be driven out, for example by reducing waste. 7,000 operative hours of data have been collected across 32 waste product categories.
The project has developed a report on how the housebuilding sector can monitor and evaluate productivity to compare different methods and demonstrate value. 66 metrics were reviewed and data on all is being collected for the project, including benchmarking of current methods. This includes collecting smart data from sites. Close collaboration and a strong spirit of innovation between the partners is driving the development of a digital system that will manage the manufacturing elements of a build, from design to completion and, in doing so, speed up the process. AIMCH has created the Guide to Creating a BIM Housing Manual, providing a framework for developers, housebuilders and stakeholders keen to adopt BIM. The guide allows housebuilders to consider and tailor their BIM transition approach, to suit their specific business drivers, needs and systems.
Whole life innovation
Design and specification choices can affect the whole-life costs of running and maintaining a house. This is particularly important for L&Q managing a stock of homes for tenants. In updating design guides, these factors have been taken into account and form part of the cost analysis.
Manufacturing Technology Centre (MTC) offered expert advice on altering processes to make use of manufacturing best practice and innovation support around business models, products and service models. Construction Scotland Innovation Centre (CSIC) offered advice, funding, facilitation and access to cutting edge equipment and expertise, improving Scotland’s global competitiveness and delivering social, environmental and economic impact.
- Barratt Homes
- Forster Roofing Services
- Limberger Associates
- Stewart Milne Group
Advanced Industrialised Methods for the Construction of Homes (AIMCH) builds on a previously successful project with a similar consortia called AIMC4 which sought to improve processes for housebuilding so carbon emission targets could be met. The consortium consulted with UKRI before submitting the proposal, which was larger than the limits of the competition. Given the commitment to share results across the sector, an exception was made to allow the project to be assessed. It was successful and received £3,938,448 of Transforming Construction funding (delivered by UKRI) over 36 months, up until March 2022.
Long Term Vision
Advanced Industrialised Methods for the Construction of Homes (AIMCH) is proving that modern methods of constructions and supply chain collaboration can really improve the quality and affordability of housing of the end user, and that more houses can be built at pace to meet society's needs and the Government's targets.
Advanced Industrialised Methods for the Construction of Homes (AIMCH) has shown that these modern methods of construction create a safer environment for workers. And improved scheduling also means their time is used well and their skills are used effectively. Workers are only asked to do what they are good at, and so avoid brickies doing block or tilers lugging tiles up scaffolding.
Thanks to the excellent collaboration along the supply chain and advice from MTC and CSIC, there has been a dramatic improvement in the capturing and sharing of data to improve processes. This is all making a powerful business case for why the industry should embrace modern methods of construction.
Building a house in parts using manufacturing processes means house builders can do more, at greater pace, yet with the same workforce. Early indications suggest 30% more. Extended across all housebuilding, that means over 70,000 more homes can be build a year with the same skilled workforce. One partner, Stewart Milne, has already seen an increase in order book revenue for 2022 of around £200m.
The Barratt Z House is testing different integrated heating and power solutions. It includes infrared panel heaters in the ceiling, an air source heat pump and vehicle-to-grid electric vehicle charging to increase the storage capacity beyond the integrated batteries. With photovoltaics on the roof and energy efficiency through the house is energy positive and will be used to see which technologies offer comfort at the lowest overall cost.
AIMCH aims to produce a single seamless digital system (an Enterprise Resource Planning or ERP system) that will allow businesses to process offsite manufacturing from concept design to completion. This will demonstrate an increase in efficiency, quality and a reduction in lead-time, downtime and processing time.
There are an estimated 120 companies engaged in AIMCH offering a powerful opportunity to show the benefits of collaboration to industry stakeholders, so the whole sector comes with them. This is being profiled on the AIMCH website and on Twitter.
If AIMCH learnings can be extended across all housebuilding, over 70,000 more homes could be built in the UK each year with the same skilled workforce.
As part of the project, Barratt Developments has built a zero-carbon home of the future at Salford University. It includes numerous technologies to reduce embodied and lifetime emissions, while providing a home that will be loved by occupants. Based on an existing Barratt home design this showcase building, built using modern methods (no bricklayers), will be used to prepare supply chains to deliver lower embodied components and meet net zero carbon standards. The Z House has cut in-use emissions by 100% and has technology enabling lifestyle-related emissions to be cut such as a fridge that reduces food waste and water saving devices. The project was used to drive innovation in Barratt’s supply chain and looked at embodied emission aspects such as using thinner bricks and tiles.
Stewart Milne is spinning out the Timber Solutions part of the business, which delivers panel components to multiple housebuilder customers and is based on AIMCH outputs. They have invested £40m in new capacity and capability including £8.2m to upgrade the existing factory in Whitney while £6m is being used to double capacity (a further 20,000 homes over 5 years) by building another factory in Falkirk using the design template developed in the project. Timber Solutions has a £300m order book and the sale will enable expansion overseas.
Early indications suggest house builders could build 30% more homes with the same skilled workforce mainly through automation of processes, better scheduling on site and removing the need for scaffolding. Forsters is targeting a 50% improvement in productivity for its skilled roofers through adoption of automation for routine processes.
One output of the project is an open-source pattern book for affordable housing that home developers can use to easily apply modern methods to their developments. It provides an off-the-shelf timber frame solution. In comparing costs across different sites in different regions, it has been confirmed that every region currently has a significantly different cost benchmark due to variations in the cost of labour, materials and subcontractors. These benchmarks will be developed to incorporate actual onsite costs and provide a true benchmark for analysis between the current standard house construction and modern methods of construction.
Homes constructed with factory-made frames and roofs tiled on the ground remove the need for scaffolding and in doing so improve the safety of the workforce. Better scheduling and planning also prevent accidents and defects. The project is working with the HSE to capture improved risks onsite, including reduced working at height; less manual handling; and reduced silica dust.
The project has calculated a 52% faster build than brick-and-block (14 vs 29 weeks), and even this seems conservative compared with Stewart Milne targets of 6-8 week builds.
The consortium deliver 35,000 homes a year between them. Impacts would be scaled up rapidly once demonstrated. AIMCH partners are already seeing business opportunities where this work can be exploited within their businesses. In the case of Stewart Milne Homes, the recommendations have been utilised in the creation on a new housing range for deployment within the business in the next 12-36 months. The project applied outputs on £1bn of new builds in 2021, with this rising to £2.5bn by 2025.