Town and Country Planning Act abandoned ‘Four-year rule’, what are the impacts?

The Levelling-up and Regeneration Act 2023 significantly advances the UK’s urban development and planning regulations. Enacted on 26th October 2023, this comprehensive reform significantly amends the country’s planning system, impacting developers, property owners, and local planning authorities, especially regarding unauthorised developments. One critical change is the amendment to Section 171B of the Town and Country Planning Act (TCPA) 1990, which alters the enforcement period for unauthorised developments.

Previously, the “four-year rule” under the TCPA 1990 provided immunity from enforcement action for developments or land uses existing continuously for four years without challenge. However, the Levelling Up and Regeneration Act 2023 extends this period to ten years in England, effectively doubling it. This extension offers local planning authorities in England a broader timeframe to address unauthorised developments, potentially reducing instances of unauthorised construction.

This amendment significantly impacts enforcement practices, development dynamics, and due diligence processes. Developers and property owners now face increased scrutiny and must exercise greater caution when undertaking projects without proper planning permissions. The extension provides local planning authorities in England with more time to curb unauthorised construction and enhance adherence to planning regulations.

The transitional provision accompanying this amendment ensures consistency in enforcement practices, maintaining the previous four-year enforcement window for developments completed or breaches occurring before 25th April 2024. However, it also introduces regional disparity in planning legislation between England and Wales, potentially resulting in divergent approaches to addressing unauthorised development.

The rationale behind extending the enforcement period is multifaceted, aiming to enhance regulatory compliance, deter unauthorised construction activities, and support sustainable development. Overall, the Levelling-up and Regeneration Act 2023 represents a significant step forward in the UK’s planning system evolution, with the extension of the enforcement period for unauthorised development standing out as a prominent amendment.

In conclusion, this legislation heralds a new era in town and country planning, characterised by extended enforcement periods and regional variation in legislation. By providing local planning authorities in England with more time to address unauthorised developments, this change aims to promote regulatory compliance and sustainable development practices. However, it also emphasises the importance of vigilance and strategic navigation of planning regulations in the evolving urban landscape of the UK.


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