Best London Housing Emergency Measures Guide to Boost Building and Cut Delays

Shoppers of policymaking and developers alike are watching closely as ministers and the Mayor unveil emergency measures to kick-start London housebuilding, a move aimed at reversing record lows in starts and completions and easing pressure on rents and mortgages across the capital.

• Fast-track option: Developers can use a time-limited fast-track planning route with a 20% affordable housing floor, at least 60% of which must be for social rent.
• Fewer upfront hurdles: Schemes in the fast-track avoid an initial viability assessment, cutting early delays and costs and speeding decisions.
• Gain-share safety net: If a scheme later becomes more profitable, a gain-share review forces delivery of extra affordable homes.
• Mayor’s new powers: The Greater London Authority can call in schemes of 50 homes plus and decide on larger green-belt proposals, giving City Hall more levers.
• Big caveat: Industry says the measures don’t fix the core problems , expensive finance and high construction costs , so meaningful new delivery depends on investor confidence and local buy-in.

Why ministers say emergency measures could break the logjam now

London’s development pipeline has slowed to levels not seen in decades, so the government and the Mayor have pushed emergency planning changes to try and get schemes moving again. The main visual here is speed: cut through upfront viability tests, offer CIL relief for certain starts and relax some design rules so planning teams can clear applications faster, at least until March 2028 or until a new London Plan lands. The idea is practical and immediate, and it smells, frankly, of crisis management , quick tweaks to get dirt moving in the short term.

Officials argue the changes will unclog delays that add months and millions to projects. For buyers and renters, faster starts could mean more homes sooner; for developers, fewer early hoops can reduce costs and uncertainty. But the emergency feel , a fixed end date and consultation window , also underlines that this is a stopgap rather than a long-term overhaul.

What developers and investors actually like , and what still worries them

Some housebuilders welcome the pragmatism. Removing an early-stage viability test is attractive because it trims a common bottleneck and can speed decisions that otherwise sit in limbo for months. Relief from the Community Infrastructure Levy for qualifying starts is another carrot that could nudge a marginal scheme into buildability.

Yet investors are uneasy about late-stage gain-share and upward-only reviews because they create retrospective uncertainty; equity investors don’t want profits clawed back unpredictably. And beyond planning tweaks, the sector keeps coming back to two constants: finance is expensive and material and labour costs are still elevated. In other words, planning reform helps, but it won’t by itself make marginal schemes viable again.

How the Mayor’s new powers change the London planning map

One of the more striking shifts is political: Sadiq Khan’s office emerges with sharper tools. The GLA will be able to call in borough decisions on schemes of 50 homes or more and decide on larger green-belt proposals. That centralisation gives City Hall the chance to override local vetoes more often, which proponents say could unblock stalled decisions and deliver homes where borough politics have held things up.

Critics say the deal between central government and the Mayor means Whitehall hasn’t fully asserted control, and that late-stage GLA powers could still deter overseas investors who dislike unpredictability. The upshot is a tug of war: a national push for more homes, met by a mayoral strategy that keeps decision-making closer to the capital but with new intervention points.

Who benefits from the fast-track and who might miss out

The fast-track route is deliberately targeted: a lower affordable housing threshold (20% instead of 35) and a requirement that most of that 20% be social rent. That will help some developments clear planning more quickly, especially those that struggle to meet higher on-site affordable quotas. Smaller or less complex schemes that can meet the 20% test are likely to be the first to move.

But many in the sector warn the measures favour schemes that are already near viability; truly marginal sites still face the same arithmetic of high financing costs and weak buyer demand. There’s also a timing squeeze , developers realistically need to have started on site by the end of 2028 to capture the benefits, which isn’t a long runway for large schemes.

Practical advice for councils, developers and buyers navigating the changes

Local authorities need to signal buy-in if this is going to work. Fast-track only helps where boroughs are willing to process and approve applications quickly, and where legal and design checks are still robust but streamlined. Developers should use the short consultation window to test assumptions and be ready to show how they meet the 20% affordable threshold and social rent split.

For would-be buyers and renters, the measures should be seen as a potential accelerant rather than an instant fix. More starts today don’t translate to new homes tomorrow; it will take time for completions to rise and for prices or rents to feel the effect. Keep an eye on schemes granted under the fast-track and public funding pots such as the Mayor’s new housing kickstart fund for signals that delivery is actually happening.

What the reforms don’t solve and what needs to come next

The blunt truth from industry insiders is that planning process change is a piece of the puzzle, not the whole picture. With interest rates still high relative to the pre-2019 era and construction costs elevated, many build-to-rent and mixed-tenure projects remain uneconomic. Longer-term fixes will need a mix of demand-side support, clearer tax incentives for long-term investors, and targeted public funding to de-risk large schemes.

If these emergency measures can be paired with steps that address finance and demand , whether that’s targeted subsidies, mortgage support for first-time buyers, or investor incentives , then the policy cocktail might finally alter London’s delivery trajectory. Until then, it’s a helpful push, but not a silver bullet.

Ready to see which schemes might benefit or how your area is affected? Check current planning consultations and watch for borough statements to see where the fast-track is likely to land.