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
We're expanding our collaborative mission by launching DB Intelligence, an exclusive market research advisory panel. Built environment professionals can now get paid to share their expertise on industry trends, products and services.
Panel members receive direct financial incentives for participating in research projects like short surveys, 1-2-1 interviews and focus groups. Register today to shape the future of the construction sector.
Planning condition discharge in England and Wales
A brief exoplanation from a building compliance expert, with further links.
Overheating guidance and tools for building designers
Guidance for dealing with element of building fabric control that have increasing importance.
Shading for housing, a design guide
From the Good Homes Alliance and British Blind and Shutter Association.
UK Standard Skills Classification (SSC)
A shared framework for describing skills needs.
Social media ban consultation comes to close
CIOB urges UK Government to consider social media’s role in careers guidance in ban debate.
The latest of eight Skills England apprenticeship units
The addition of battery manufacturing welcomed by ECA with a warning about the risks of fast-tracked apprenticeship units.
Building Control Independent Panel final report
A precis of a key report led by Dame Hackitt with full recommendations and link to the government response.
Building Safety recap April, 2026
A short and longer run-through of the month, with links to further information and sources.
CIAT May 2026 briefing.
From medieval scribes to modern word art.
ECA welcomes crackdown on late payment and push for clean energy, whilst CIOB seek fixed cladding removal timeframes.
Cyber Security in the Built Environment
Protecting projects, data, and digital assets: A CIOB Academy TIS.
Managing competence in the built environment
ITFG publishes new industry guide on how to meet the ICC principles.
The UK's campaign to reduce noise pollution: Mythbusting, articles and topic guides.





















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