Mace Construct’s Build Smart, Build Better report draws on five years of project data to examine why construction productivity remains stubbornly low. Tim Carey, Director and Head of Design at Mace Construct, spoke to the Industrialised Construction Journal about why the biggest gains depend on decisions made before the project reaches site.
Construction productivity is often treated as a delivery problem. Once work starts, project teams are expected to improve sequencing, reduce downtime and find efficiencies against a design, procurement route and supply chain that may already be fixed.
For Tim Carey, Director and Head of Design at Mace Construct, that places the emphasis too far downstream.
“The majority of a project’s productivity potential is determined before mobilisation,” he says. “Productivity is therefore not primarily a site management issue; it is fundamentally a project set-up issue.”
Mace Construct’s report gives that argument an evidence base drawn from 234 projects delivered between 2019 and 2025, examining hours worked, value generated, margin retained, workforce composition, contract structure, digital maturity and modern methods of construction.
The productivity commitment point
Carey identifies RIBA Stages 0–2 as the period in which the main productivity levers remain available. Decisions on procurement, contractor involvement, design maturity, PMV and MMC strategy, digital coordination and supply chain integration become harder to change once detailed design is under way.
The report recommends treating the end of RIBA Stage 2 as a “productivity commitment point”. By then, the delivery strategy should show how the building will be produced, not simply what the asset should look like.
It doesn’t mean freezing an immature design. It means bringing construction and manufacturing knowledge into the process early enough to shape components, interfaces and sequencing.
Once a project reaches RIBA Stage 4 or 5, Carey says, “many of the productivity levers have already been lost”. Site teams can improve execution, but cannot readily recover opportunities for standardisation or prefabrication that were never designed in.
Designing around production
Carey describes designing for production as approaching a building in the way a manufacturer would approach a product. The operational brief at Stage 0 should establish how the asset needs to perform. During Stages 1 and 2, teams can identify repeatable components, standardise interfaces and assemblies, assess MMC opportunities and agree an appropriate PMV ambition.
This allows coordinated models to be developed before site work begins. It resolves interfaces while prefabrication, sub-assembly and factory manufacture are still viable options.
“Designing around logistics, installation sequence, and repeatability, not just design intent is also critical,” says Carey.
Manchester Airport Terminal 2 shows what that can deliver. For Pier 2 Phase 2, Mace Construct and WSP developed a kit of parts for the fixed links and nodes connecting the pier to the terminal. Thousands of individual components were reduced to fewer than 100 repeatable sub-assemblies, with around 80% of construction activity completed under factory conditions.
The report records more than 5,400 personnel hours delivered offsite, around 79,000 fewer operative movements in the live airside environment and gross value added per operative hour of £399, compared with around £150 using traditional methods.
PMV is not the result
The report also challenges the assumption that a higher PMV figure automatically indicates a more productive project.
“PMV is an input, not an output,” Carey explains. A team can increase pre-manufactured value through expensive manufactured solutions without achieving a corresponding improvement in programme, labour efficiency or commercial performance.
Mace’s data found that high-MMC projects generated around 50% more commercial value per worker than comparable projects of similar scale and type. More of their work contributed to commercial value rather than being absorbed by clashes, coordination failures and rework.
Carey sees PMV as one indicator within a wider decision-making process: a way to assess how much work is being transferred into controlled manufacturing environments and to test opportunities for standardisation and repeatability.
“The right question is not ‘how do we maximise PMV?’ but rather ‘where can pre-manufacture create the greatest reduction in rework, interfaces, labour intensity, programme risk and carbon?’”
Earlier and more integrated
Delivering that consistently requires a different relationship between designers, contractors and specialist manufacturers. Carey argues that designers often advance too far before construction and engineering knowledge enters the process, while manufacturers are appointed after the decisions they could have influenced have been made.
The alternative is an integrated delivery team working to common production objectives. Designers need to understand manufacturing and assembly constraints. Contractors must be involved before key choices are fixed. Specialist suppliers should be in the room during concept and developed design.
Procurement is central. The report found that early-involvement models on large projects retained more value than traditional single-stage tendering against a completed design. Earlier engagement also supports digital coordination, logistics planning and more stable supply chain relationships.
Carey compares the required model with aerospace and manufacturing supply chains, where designers, builders and manufacturers contribute simultaneously rather than sequentially. Long-term pipelines and repeat systems would allow knowledge to accumulate instead of being dispersed when each project ends.
Early contractor and specialist manufacturer involvement, he argues, should become the default on major projects.
MMC, digital maturity, logistics, workforce stability and margin retention all depend on timing. Get the sequencing wrong and none of them pay back. Site teams can’t out-work decisions made before they arrived – fixing how projects are set up is the only lever left.
“Productivity on site is the wrong target,” Carey says. “What the industry needs is productivity by design.”
Take a deeper dive into Mace Construct’s Build Smart, Build Better at macegroup.com
This article originally featured in the Industrialised Construction Journal, Issue 9. Explore the Industrialised Construction Journal HERE.
