B11 Prefabricated Building Units Checklist
Index:
Issues:
Problems:
Misunderstandings:
- It is assumed prefabrication reduces waste, because no off cuts occur on site and no excess materials need to be delivered to site
- In reality waste occurs and on site it usually ends up in the skip, shared by many trades and one man’s waste can spoil another’s man’s, without hope of reuse and heading for landfill
- In a factory there is more chance that off cuts can be stockpiled and reused to complete tasks
Solutions:
Consider:
- Off-site prefabrication: Construction Industry Skills shortage needs more factory production
- On-site temporary factory production, benefits: less vehicles to deliver materials, aiming for factory conditions and better quality work and less waste
- Set up on-site factory-production in weatherproof enclosure on solid base and thermally comfortable conditions
- Use of standard size components without cutting, to minimise offcuts and waste
- Balance with avoiding transporting large volumes of air
- Panelisation in preference to volumetric, unless fully equipped, furnished and heavy
Avoid:
- Factory controlled tolerances being spoiled by poor assembly tolerances on site
- Cassette panels being delivered without any offcuts to permit propping and spacing off, causing operatives to cut out studs to do this
- Composites which are difficult to recycle although there is some evidence that technology is catching up and permitting easy separation in the future
Minimise:
Substitute:
Methods of Construction
- Preassembled and pre-insulated panels
- Wall, floor or roof preassembled and pre-insulated panels
- Compound timber sections in preference to solid timber studs and joists
Materials:
- Recycled newspaper cellulose fibre thermal insulation, spray into open panels, loose fill in panels, dry injected through holes cut and filled by machine
- Timber studs in preference to steel studs
- Composite timber studs in preference to timber studs
Health:
- Adopt vapour open construction in preference to vapour closed construction to reduce risk of condensation, mould and asthma and avoid risk of interstitial condensation and rot
Wellbeing:
Biodiversity:
- Avoid trying to incorporate boxes and roosts within the panels destroying the integrity or performance of the panels
- Incorporate them within the cladding zone
Safety:
Precautionary principle:
Resource Efficiency Issues:
- Prefabrication has the potential to reduce waste
Reduce:
- Reduced waste opportunities with factory condition production and segregated waste containers
Reclaim:
Reuse:
- Reuse timber studwork
Recycle:
- Recycled newspaper cellulose fibre thermal insulation, spray or loose fill in panels
Recover:
Waste Issues:
Hazardous waste:
Deleterious Substances:
Waste statistics
- 30 m tonnes (33% of 90 m. tonnes/year) of waste is offcuts
- Site practices tend to put all waste into mixed skips and the likelihood of a scrap coming out of a mixed skip are poor.
- Factory production segregated waste and clean methods of working mean scraps are more likely to be used to finish a job than not.
Waste minimisation
End of Life options
HERACEY:
Healthy:
Environmental:
Resourceful:
Appropriateness:
Competence:
Effectiveness:
Yardstick:
Maintenance issue:
Industry/Sector Initiatives:
Information sources:
© GBE NGS ASWS BrianMurphy
aka BrianSpecMan
25th August 2014 – 11th December 2016
B11 Prefabricated Building Units Checklist
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© GBE NGS ASWS BrianMurphy
aka BrianSpecMan
25th August 2014
B11 Prefabricated Building Units Checklist
See Also:
GBE CPD
GBE JARGON BUSTER
Initials, Abbreviations, Acronyms
- MMC
Names and phrases
- Modern Methods of Construction (MMC)
GBE PROJECTS
GBE SPECIFICATIONS
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GBE LIBRARY
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© GBE NGS ASWS BrianMurphy
aka BrianSpecMan
25th August 2014
