What is MMC, and how is PMV calculated?


Modern Methods of Construction (or MMC) is constantly being redefined with the creation of new production styles and platforms designed for speed and ease of assembly, reducing material use and wastage, and, in many circumstances, relying less on skilled trades and traditional construction techniques. But it doesn’t stop there, the aim of achieving more consistent quality or tighter tolerances is also taken into consideration making sure that the speed of construction doesn’t impair the quality of the build.

Government policy and investment is spurring the increased adoption of frames, panels and other MMC, which address multiple challenges. At the forefront is sustainability concerns, like net zero targets and resource scarcity. Linked to that are rising material costs and long lead times. There’s also a shortage of skilled labour available to build in traditional onsite techniques.

UK construction is adapting to multiple challenges MMC is characterised by partial or complete offsite manufacture that offers faster, more efficient, less carbon-intensive ways of constructing lightweight buildings. Having invested in helping the UK construction industry to develop MMC solutions, the government is promising that those solutions will be procured on central projects to drive uptake of them more widely.

The Government’s Affordable Homes Plan, delivered through Homes England, specifies that the projects it funds must contain a minimum of 25% MMC. It also sets a measure against which MMC projects will be assessed – the Pre-Manufactured Value (PMV). This is the financial proportion of a project’s gross construction cost through premanufacturing. To pass Homes England’s MMC test you need to have at least a 55% PMV

Calculating PMV

To calculate a building’s PMV, each element that is delivered through an MMC process or product will add to the overall percentage. There are seven categories awarding percentage points. For example, category one is Pre-manufactured 3D primary structural systems which includes volumetric modular housing units. This will give you the highest percentage. In category three Pre-manufacturing components (non-systemised primary structure) components - such as beams, staircases or trusses would also boost your percentage.  Category six deals with building products and systems that reduce labour on site and improve productivity. This is where the Weber range of products would sit, for example specification of weberwall brick a lightweight modern alternative to traditional brickwork would improve the PMV of the project.

The MMC framework identifies the following categories:

  • PMV Category 1

    Category 1

    Pre-manufacturing – 3D primary structural systems  
    e.g. volumetric units, pod construction

  • Weber UK

    Category 2

    Pre-manufacturing – 2D primary structural systems 
    e.g. flat units or frames, complete with utilities or completed on site

  • PMV Category 3

    Category 3

    Pre-manufacturing – Non systemised structural components
    e.g. load bearing beams, columns, walls and slabs made from timber, steel or pre-cast concrete

  • PMV Category 4

    Category 4

    Pre-manufacturing – Additive Manufacturing 
    e.g. digital design and manufacturing techniques, 3D printing

  • Weber UK

    Category 5

    Pre-manufacturing – Non-structural assemblies and sub-assemblies 
    e.g. kitchen assemblies, roof, floor and partition cassettes, pre-hung doorsets

  • PMV Category 6

    Category 6

    Traditional building product-led site labour reduction/productivity improvements
    e.g. products manufactured in large format or pre-cut, easy-install

  • PMV Category 7

    Category 7

    Site process led labour reduction/productivity improvements
    e.g. site robotics, productivity planning tools, autonomous plant and equipment

The final finish

All solutions require a suitable finish and render is a popular option – but there are different rendering options depending on the type of construction. If you would like to learn more, please see our Guide to renders and decorative finishes for modern methods of construction which will help you identify what you need from a render system for it to deliver the required performance, what the technical challenges it has to meet, and how you make sure it looks right once installed.

Also available is our RIBA approved CPD Modern render systems for framed construction and other MMC solutions that can be conducted face-to-face at your location of your choice, or virtually over MS Teams.

Click Compare to help you choose the right product for your project, if you need further assistance please email technical@netweber.co.uk