Savills responds to publication of ‘Support for Housebuilding’ measures

A summary of the emergency, time-limited measures, and our initial thoughts, are set out below:

• Relaxed design guidelines to support higher densities, including increased flexibility on cycle parking provision.
• Dual aspects requirements are now governed through Building Regulations, albeit there is still a desire to maximise provision of dual aspect units.
• A reduced threshold for being eligible for the Fast Track route (whereby a Financial Viability Assessment is not required) at 20% affordable housing is now adopted (35% on public land). This is referred to as the ‘time limited planning route’ as this is not a permanent change.
• Co-living and purpose-built student accommodation (PBSA) schemes do not benefit from the time-limited planning route or schemes where either of these (or together) comprise of 50 per cent or more of total scheme residential Gross Internal Area (GIA) floorspace.
• Also for sites on industrial land that do not re-provide industrial floorspace capacity, the 20% affordable Fast Track route will not apply.
• The desired affordable housing tenure split remains at 60% social rent 40% intermediate.
• The time-limited revised Fast Track affordable housing thresholds will be available for planning applications which have been validated by a local planning authority by 31 March 2028. This timeframe has been extended from the consultation draft in response to feedback from the industry.
• Schemes that commit to providing affordable housing at or above the relevant affordable housing thresholds, during the new time-limited planning route, will be eligible for grant funding.
• The Late Stage gain-share mechanism has also been replaced by an Early Stage Review, aligning directly with the Greater London Authority’s (GLA) current Fast Track route, with no further reviews required beyond this.
• The Early Stage Review will be triggered where an agreed build out milestone is not met within a stipulated time period, with a default position comprising of a build out milestone of a first-floor slab to be achieved within 30 months, starting from the grant of planning permission.
• The new time-limited planning route can also be utilised by developments with existing planning permission(s), with the GLA and government strongly encouraging local planning authorities (LPAs) to favourably progress deed of variations to S106 agreements and S73 amendment applications where the proposals would meet the new minimum requirements and eligibility criteria under the time limited planning route.

In addition to the LPG changes now in force, secondary legislation is to be brought forward to expand the mayor’s Call In Powers, which should be in force in May 2026. This will mean that schemes of 50 dwellings or more are eligible to be called in for determination by the mayor. The current threshold – in place since 2008 – is 150 dwellings.

Changes to the Community Infrastructure Levy (CIL) Regulations are also to be brought forward for temporary CIL relief for eligible schemes.

Schemes that provide 20% affordable housing (with at least 60% social rent tenure) can secure a 50% reduction in the borough CIL charge, but this is now to be viability tested in the final version of the LPG. This CIL reduction can increase for schemes delivering more than 20% affordable housing. The government “intend to consult on the draft CIL amending regulations as soon as possible in the spring”.

The adoption of these temporary emergency measures, as part of the Support for Housebuilding LPG, represents a positive and proactive response to the immense challenges faced by current housebuilders in this economic and political climate.

The government and GLA hope that the combination of increased design flexibility, more efficient viability mechanisms, and financial support will act as a catalyst for accelerated housebuilding across London. This is to enable new schemes to come forward and help stalled schemes progress.

The success of these measures in actually delivering more homes across London will clearly be dependent on a number of factors, including those outside of planning control. It will also depend on how LPAs process applications or stalled sites with these measures in place, and their willingness to engage with them. The extent to which the Mayor utilises his newly expanded powers will also be important.

The newly published LPG sits alongside the updated ‘Accelerated Funding Route’ (November 2025). This allows grants for development in the Affordable Homes Programmes. Further detail on the funding guidance can be viewed here.

Savills looks forward to the positive outcomes that these emergency measures may unlock for housing delivery across the capital.