Get Cusping

Prof Nick Eyre (Leader of Centre of Research into Energy Demand Solutions) regards the heating of buildings (primarily dwellings) as one of the most challenging sectors for significant reductions in carbon emissions. These currently account for about 25 of emissions, and proposals for substantial reductions depend on heat pumps (implying decarbonizing of the grid) and some green gas. The difficulty is being hugely inflated by the scale of under-occupation, possibly amounting to nearly half the bedrooms in the UK (say 10m) not being required for that purpose. Taking the Government
Downsizing home ownersestimate of demand at 300,000 new dwellings per year, the sub-division of existing stock represents a potential for about 16 years supply without any new building. This is critical as 50 of emissions are embodied at substantial completion, and emitted in the decade when the greatest emissions reductions are required. New building also impacts on biodiversity and carbon in plants/soils.
Since 2016 there has been a statutory duty for councils to maintain registers of those wanting to self/custom-build and to permit/provide serviced plots at a number equivalent to those on the registers. Virtually all councils are failing in this duty. Were councils to keep registers of those wanting to downsize (estimated at about 8m households in the UK), under-occupiers could be partnered with those wanting to custom-build (estimated at over 10m). Permissions for residential sub-divisions would be conditional on the whole building being upgraded (to equivalent of CSH C or above current average below D) and the use of low or carbon negative materials. Custom-splitting (cusping) enables downsizing-in-place (with improved mobility standards) and utilises existing services/facilities. Crucially, sub-divisions would result in the occupation of the space being heated and insulated. These multiple benefits point to residential sub-divisions becoming the main target for Government incentives aimed at meeting housing needs.





Trigger (intervention)




Feedback Dynamics


Timescale and scaleability





Daniel Scharf

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