21 July 2026
Planning Alert: Changes to London Green Belt CIL Relief
Government proposes removing CIL relief for London housing projects partially built on green belt land.
The government has recently proposed disqualifying certain London-based housing schemes from temporary Community Infrastructure Levy (CIL) relief. Specifically, projects that are even partially delivered on the green belt—by as little as 10%—may no longer benefit from these financial exemptions. CIL is a standard charge levied by local authorities on new developments to help fund local infrastructure. Temporary relief measures were originally designed to stimulate housing delivery and development, but this new policy proposal indicates a decisive shift away from incentivizing green belt encroachment. At London Extend, we are monitoring these legislative shifts closely. This proposed change means that developers and homeowners looking to build on or near protected land will face increased financial contributions and tighter scrutiny. It highlights a stricter national stance on preserving London’s green spaces, making it absolutely crucial for anyone planning a major residential project to understand their potential levy liabilities before beginning.
For London homeowners, navigating the complexities of the Community Infrastructure Levy (CIL) is often one of the most daunting financial aspects of a major property upgrade. While the latest government proposal primarily targets larger housing schemes bordering the green belt, the ripple effects of this policy shift are highly relevant to private homeowners planning significant extensions, annexes, or self-builds on the edge of the capital.
Firstly, it signals a hardening of planning policies regarding London's green belt. If you live in outer London boroughs like Bromley, Enfield, or Richmond, where properties frequently abut protected land, local planning authorities are likely to become even more stringent. Gaining planning permission for large outbuildings or wrap-around extensions that significantly increase the footprint of a property near these protected zones will require meticulous design and robust justification.
Secondly, this news underscores the critical importance of understanding CIL liabilities before you break ground. CIL is calculated based on the net additional gross internal floor area of your project. Typically, standard residential extensions under 100 square metres are exempt from CIL, provided they do not result in a completely new dwelling. However, if your ambitions include building a separate habitable dwelling in your garden or an extensive overhaul that crosses the size threshold, you could be hit with substantial fees. The potential removal of relief for green belt-adjacent projects shows that local and national authorities are willing to use CIL as a strict spatial planning tool.
At London Extend, we see this as a vital reminder that early planning and expert architectural advice are non-negotiable. If you are considering expanding your home, especially in ecologically sensitive or edge-of-city locations, you must factor in potential local authority levies from day one. Our team of expert planners and architectural designers specialize in maximizing your property's potential while keeping you safely within the bounds of exemptions wherever possible.
We navigate the bureaucratic red tape so you don't have to. By utilizing clever design strategies—such as optimizing your permitted development rights or ensuring your extension stays just under the CIL chargeable threshold—we help protect your budget from unexpected government taxes. As UK planning laws rapidly evolve, having London Extend by your side ensures your dream home extension remains both legally compliant and financially viable.