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MMC Modern Methods of Construction (CPD) G#309 N#310

GBE CPD MMC Modern Methods Of Construction A03 BRM 180520 S1 PNG

MMC Modern Methods of Construction CPD

GBE > Encyclopaedia > Files > CPD > G#309 N#310

MMC Modern Methods of Construction CPD

  • MMC Modern Methods of Construction
  • © 2007 – 2020
  • This Presentation on GBE:
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  • ‘a broad range of processes that aim to produce more, better quality homes in less time.
  • The definition is categorised in terms of products:
  • Panellised, volumetric, hybrid and other methods,
  • and may involve off site manufacturing.’
  • NAO (National Audit Office)

GBE Brain Dump

  • MMC

Unintended Consequences MMC

  • Building more housing rapidly to solve housing crisis using the wrong materials will add to:
  • ‘Carbon Burp’ if carbon intensive materials (Plastics) are used or
  • ‘Energy Burp’ is using energy intensive materials (Metals and mineral fibres) are used
  • let alone other issues (described below)


  • Many timber-based methods as well as metal or concrete
  • Insulating, thermal bridge free, airtight construction, Low Embodied Carbon, Low energy demand in use, no overheating, Bio-based v petro-chemical construction
  • Better buildings than business as usual, lowering prices of home ownership or more business as usual profiteering at the expense of customers?
  • ‘Need for speed’ by Government, at the expense of getting it wrong, again.
  • Quality of MMC for manufacturers or quality of building for users?

Offsite process and smart Tech influence on Construction

  • Improvements in competency
  • Tolerance (On-site inaccuracy accommodation)
  • Modular design (As bought material sizes) and waste minimisation
  • Design for construction/assembly and deconstruction/reconstruction for second life applications
  • BIM with CAD CAM capability
  • BIM with clash detection,
  • BIM with materials intelligence
  • BIM with energy and comfort modelling apps
  • Logistics Software and logistics of supply to sites

MMC Format:

  • Framed, Infill, Pod, Panel, Modular, stacking assembly and joining techniques.
  • Modular acknowledging the size of materials to reduce off-cut waste
  • Modular to enable reuse at end of first life.

Building Performance:

  • Strength, Fire, Acoustic, Thermal, Thermal bridging, wind and air tightness, Moisture integrity
  • MMC cannot be looked at in isolation from performance and how the building will be serviced (temperature, humidity, etc. control)
  • And if it is to be Vapour open or Vapour closed construction and materials choices subsequently

Forms of off-site construction and delivery

  • Production benefits associated with off site construction including modular construction, factory construction, automation and robotics, and 3D printing

Pods and Modules; How installed

  • Consider how pods and modules are inserted into framed construction, into or onto floor thickness,
  • interface with preceding and following trades,
  • maintaining all performance integrity, connecting to services and finishing off the connections and accesses.

Modules: How assembled

  • Consider how modules are assembled and maintaining thermal bridge free construction
  • Consider how modules attach thermally-broken from and to:
    • any other structure: frames;
    • and to secondary elements: Stairs, landings, balconies

Framing and thermal bridges

  • Needs to consider framing/non-framing methods of panel production,
  • alternative framing materials and potential for thermal bridging,
  • impact of strengthening at edges and openings on the increases in thermal bridges.


  • Consider acoustic performance of external fabric with various thermal insulation choices

Insulation choices

  • Need to consider insulation choices for:
    • winter heating (normal) and
    • summer cooling (essential with MMC) and risks of overheating or
    • risk of high energy/carbon over life of building with retrofitting ‘comfort cooling’ air conditioning.


  • Consider top floors and single aspect
  • to be able to stay cool in summer overheating potential
  • Security,
  • smells,
  • noise and night time noise in use,
  • windows and vents

Panel/Joint and Psi values

  • Needs to consider insulation material choices and potential thicknesses
  • and (thermal bridge psi values increase in thicknesses.

Insulation thickness: on Module Size

  • Thickness of panels size
  • impact on Modular and Panels on the transport implications.

Joints: Air and Wind Tightness

  • Consider panel and semi-modular assembly and wind and air tightness
    • regimes and
    • details of any Penetrations
    • Including Services

Integrating Services

  • Integrating services
  • rewiring during life,
  • wiring across junctions and joints,
  • adding new services during use


  • All or most of the site issues move to the factory
  • or duplicate the issues on site and in the factory
    • –Waste,
    • –H&S,
    • –Wet trades,
    • –Tolerances,
    • –Factory Dry, weather-free conditions
    • –Skills shortages,
    • –Training to Approved status,
    • –No time to care

Management need to manage

  • Management, Supervision,
  • Modern and Innovative methods need Trade Toolbox talks

Impact of off-site construction on

  • assembly,
  • time on-site,
  • quality,
  • waste minimisation,
  • Safety

Social, economic, environmental and cultural factors:

  • Consider:
    • –Bio-based methods of construction: solid wood, CLTP, LTF, SIPS, ISPS.
    • –Bio-based insulation, consider Embodied Carbon. Operational Carbon, Whole Life Carbon, Whole Life Costs, Whole Life carbon Costs.
    • –Plastic free construction.
    • –Products accessories and systems on the market.

Different production models

  • Trade schools and skilling for the tasks.
  • Wet or dry trades,
  • pre-drying,
  • curing,
  • performance optimisation


  • Traffic, overnight haulage, preplanning route, consolidation yard, final delivery, cranes, handling,

On-site installation

  • Stacking, interlocking, guiding technology or inserting into existing, sliding, inserting from cranes,
  • Safety issues
  • Tolerances, assembly creep, replacing intermediate units/panels, design for assembly, designing for deconstruction, Servicing, integrity proofing,
  • Energy performance
  • Building Regulations and SAP or SBEM
    • –are not good enough for Climate Emergency

%%% More work to do


  • –Passivhaus & EnerPHit
  • –AECB CarbonLite,
  • –LETI,
  • Users Expectations
  • Better informed public are expecting better
  • If MMC want to show the Construction Industry how to do things in a competent manner, then they need to address everything.
  • Retrofitting MMC
  • Retrofitting inadequate MMC will be impractical and makes no financial sense.
  • I would want to sue the MMC sector for ignoring the obvious and sue them for ignoring climate change and for creating overheating buildings.
  • Comfortable with no overheating
  • Passivhaus energy standards are based in comfort conditions
  • Economy/market
  • Viability of main electricity and carbon intensity to serve the MMC services and maintain a low carbon solution
  • Procurement
  • MMC manufacturer as contractor and site works as sub-contractor
  • User/stakeholder requirements.
  • PII risk free
  • Competent, condensation free, mould free, overheating free, no fire risk, no unsellable homes,
  • Detailed Analysis
  • MMC
  • Offsite Configurations:
  • Volumetric,
    • –Modular
  • Domestic: parts of flats or houses
  • Motels: Bedroom bath corridor bath bedroom
    • –Podular
  • Bathrooms
  • Kitchens
  • Plant rooms
  • Freezers
  • Panellised: Walls, floors, roofs, partitions
  • Turn key solutions

–Fast food chains: Complete fit out at factory

  • Opportunities:
  • Off-site factory production
  • On-site in factory conditions
  • Waste minimisation in factory, minimal site waste
  • No surpluses delivered to site, used in factory
  • Packaging waste onsite minimisation
  • Efficient site work

–Unhindered ground works

–Servicing connection and completion

  • Lean Construction
  • Aim to minimise waste in all its forms

–Management time

–Labour time

  • Factory production can exploit this well

–Production line efficiencies

–Trade or task Specialisation

–JIT deliveries

  • Lean Gone Wrong
  • But lean is being misinterpreted and going wrong, seriously wrong



  • Design Issues:
    Factory Production
  • Created to standard/design sizes

–Ignore site reality

–Base inaccurate setting out?

  • Site/Factory tolerances

–sometimes things go wrong

  • Site operative idea of tolerances don’t match factory
  • Wasted on site if wrong size
  • Design Issues:
    Site production
  • Create site factory under canvas
  • When offered up, if wrong size, rework and reinstall
  • Potentially less waste
  • Design Issues: Insulation
  • Rarely have any thermal mass or decrement delay
  • Use thin high embodied carbon and embodied energy insulating materials
  • Gappy insulation > Performance Gap
  • Gaps between units? Heat loss
  • Design Issues: Installation
  • Big strong operatives may damage fragile parts
  • Site operative idea of tolerances don’t match factory
  • Wasted on site if wrong size
  • ‘Helping hand’ supports permit adjustment

–Potentially one man operation

  • Procurement:
  • High % of Costs: are in the Modules
  • Low % of Costs: Site works
  • Profits for attendance and preliminaries by Main Contractor if % become large
  • Site Works Contractor/Operatives may become a subcontractor of the Modular manufacturer

–More control over site setting out and tolerances

  • Site Preparation:
  • Similar to Normal sites
  • All services in and wastes out
  • Landscape: Hard, soft and wet
  • May include reclaim and reuse of water
  • May include permeable pavement
  • Bases for MMC need to be accurate
  • Logistics Issues
  • Volumetric:

–Transporting lots of fresh air

–Avoided by panellised

  • Just in time delivery

–Needs buffer park-up place near site

  • Road closures

–Expensive crane hire

  • MMC Elemental Assemblies
  • Materials and methods
  • Light Timber Frame (LTF)
  • Light Metal Framed (LMF)
  • Prefabricated panel construction
  • Metal Stud External Walls
  • Greenwich Millennium Village Phase 2a
  • Egan initiative implemented:
    prefabrication off-site, simple
    assembly on site,
    of site waste
  • later on-site
  • Metal frame walls
  • Balloon frame Platform Frame
  • Concrete Frame

Infill panels

Curtain wall

  • Factory Prefabrication:
  • Conditions ensure no deterioration
  • No mud or cement splashes
  • No rain to spoil
  • Use of all the materials supplied
  • Reusing until all is gone
  • Virtually no waste
  • Compound Studs ‘I Studs’ to accommodate more thermal insulation
  • MMC Modern Methods of Construction
  • Opaque Timber Walls Timber Constructions
  • Compound Studs ‘I Studs’, inner and outer boards and thermal insulation
  • Compound studs ‘I studs’, inner and outer boards and thermal insulation
  • Insulated structural Panels

Roof panels create

Habitable Roof Space

Platform Frame

  • SIP Structural Insulated Panel
  • SIP Structural Insulated Panel
  • Structural Insulated Panels

Roof panels create

Habitable Roof Space

Platform Frame

  • Load-bearing Cross Laminated Timber Panel walls (CLTP)
  • Opaque Timber Walls Timber Constructions
  • Load-bearing Structural Cross Laminated Timber Panel
  • Cross Laminated Timber Panel
    shear walls floors and roofs
  • Cross Laminated timber Panels

Roof panels create

Habitable Roof Space

Platform Frame

  • Load-bearing Timber blockwork
  • Opaque Timber Walls Timber Constructions

© GBE 2007 – 2020

© GBE GBC GBL NGS ASWS Brian Murphy aka BrianSpecMan **
29th April 2014 – 20th April 2021

MMC Modern Methods of Construction CPD


GBE CPD MMC Modern Methods Of Construction A03 BRM 180520 9H1 PNG

GBE CPD MMC Modern Methods Of Construction A03 BRM 180520 9H1 PNG

GBE CPD MMC Modern Methods Of Construction A03 BRM 180520 9H9 PDF

GBE CPD MMC Modern Methods Of Construction A03 BRM 180520 S1 PNG


© GBE GBC GBL NGS ASWS Brian Murphy aka BrianSpecMan **
29th April 2014 – 20th April 2021

MMC Modern Methods of Construction CPD
See Also:

GBE Jargon Buster

  • IMC
  • MMC
  • Factory Assembly
  • Innovative Methods of Construction (IMC)
  • Modern Methods of Construction (MMC)
  • Off-site
  • Prefabricated
  • Pre-assembled


CPD Topics N#478

GBE CPD About Specification G#560 N#580

GBE Brain Dump

© GBE GBC GBL NGS ASWS Brian Murphy aka BrianSpecMan **
29th April 2014 – 20th April 2021

MMC Modern Methods of Construction (CPD) G#309 N#310

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