United Kingdom

policies

The NPPF provides detailed information promoting the effective use of land by prioritising upward extensions under section 11. It emphasises that the planning policies and decisions should support opportunities to use the airspace above existing residential and commercial premises for new homes.
The House of Commons also specify specifies the prioritisation of retrofit and reuse of existing buildings over new builds to conserve resources, minimise embodied carbon emissions, reduce demolition waste and deliver cost-effective solutions to delivering on housing demand.
The Net Zero Strategy published in 2021 sets out the measures that will be taken by UK to increase the use of timber in construction with the primary action being establishing a cross-government and industry working group tasked with identifying key actions to safely increase timber use and reduce embodied carbon.
The UK government has also published documents like the Timber in Construction Roadmap to focus on the promotion of the use of safe, high performing timber construction and introduced the Timber in Construction Innovation Fund which will provide £1.7m of funding to homegrown wood and wood fibre in construction.

The City of London City Plan 2040 highlights that the City Corporation will facilitate significant growth in office development of the highest quality to meet projected economic and employment growth.
Strategic Policy S4 specifies that the City’s office floorspace stock will be increased by a minimum of 1,200,000 m2 net during the period 2021 to 2040.
The policy DE1 for Sustainable Design also mentions that the development proposals should follow a retrofit first approach, thoroughly exploring the potential for retaining and retrofitting existing buildings as the starting point for appraising site options.
Several other policies like OF1 and OF2 in the City of London City Plan 2040 provide further information for prioritising retrofitting existing buildings and increasing office floorspace.

The Westminster City Plan 2019-2040 specifies the locations where the possibility of extensions having one storey or more will be supported. For example, the context height for the wider Paddington area, Marylebone flyover/Edgeware road junction and Victoria is identified as 6 residential storeys (20m) with a varied context.
The City Plan Approach mentions that design will prioritise sustainable construction where specialist attention will be given to retrofitting the historic buildings.
The Design and Heritage section recommends sensitively refurbishing or retrofitting buildings prior to demolition steering the construction of upward extensions.