Pre-manufacturing (2D primary structural systems)
Modern Methods of Construction, Introducing the MMC definition framework, published by Ministry of Housing, Communities & Local Government (MHCLG) in 2019 defines 7 categories for MMC:
- Category 1 – Pre-manufacturing (3D primary structural systems).
- Category 2 – Pre-manufacturing (2D primary structural systems).
- Category 3 – Pre-manufacturing components (non-systemised primary structure).
- Category 4 – Additive manufacturing (structural and non-structural)
- Category 5 – Pre-manufacturing (non structural assemblies and sub-assemblies).
- Category 6 – Traditional building product led site labour reduction / productivity improvements.
- Category 7 – Site process led site labour reduction / productivity / assurance improvements.
Category 2 – Pre-Manufacturing (2D primary structural systems) is defined as:
‘A systematised approach using flat panel units for basic floor, wall and roof structures of varying materials which are produced in a factory environment and assembled at the final workface to produce a final three-dimensional structure. The most common approach is to use open panels or frames, which consist of a skeletal structure only, with services, insulation, external cladding and internal finishing being installed on site.
‘More complex panels – typically referred to as closed panels – involve more factory-based fabrication and include lining materials and insulation. These may also include services, windows, doors, internal wall finishes and external claddings. The system includes structural performance for primary walls and all floors (note – this excludes unitised or composite external walling systems that are not load bearing included in Category 5).’
[edit] Related articles on Designing Buildings Wiki
- British post-war mass housing.
- Design for deconstruction.
- Design for Manufacture and Assembly (DfMA).
- MMC definition framework.
- Modern methods of construction.
- Off site, on track.
- Off-site construction.
- Off-site prefabrication of buildings: A guide to connection choices.
- Prefabrication.
- Pre-manufactured value
- Volumetric.
Featured articles and news
The sad story of Derby Hippodrome
An historic building left to decay.
ECA, JIB and JTL back Fabian Society call to invest in skills for a stronger built environment workforce.
Women's Contributions to the Built Environment.
Calls for the delayed Circular Economy Strategy
Over 50 leading businesses, trade associations and professional bodies, including CIAT, and UKGBC sign open letter.
The future workforce: culture change and skill
Under the spotlight at UK Construction Week London.
A landmark moment for postmodern heritage.
A safe energy transition – ECA launches a new Charter
Practical policy actions to speed up low carbon adoption while maintaining installation safety and competency.
Frank Duffy: Researcher and Practitioner
Reflections on achievements and relevance to the wider research and practice communities.
The 2026 Compliance Landscape: Fire doors
Why 'Business as Usual' is a Liability.
Cutting construction carbon footprint by caring for soil
Is construction neglecting one of the planet’s most powerful carbon stores and one of our greatest natural climate allies.
ARCHITECTURE: How's it progressing?
Archiblogger posing questions of a historical and contextual nature.
The roofscape of Hampstead Garden Suburb
Residents, architects and roofers need to understand detailing.
Homes, landlords. tenants and the new housing standards
What will it all mean?



















Comments
This article is very informative, thank you for sharing helpful content