Our NPPF 2026 Update – Changes to National Planning Policy Framework

The key policy changes to the National Planning Policy Framework (NPPF 2026) affecting heritage sites.

By Sam Mayou, PG Dip Arch Cons, Director, CAD Heritage

On 17^th August 2026, the UK Government published a completely overhauled and restructured National Planning Policy Framework (NPPF 2026), following an extensive consultation process.

This 130-page document replaced the previous December 2024 version of the NPPF with a new rules-based system designed to accelerate housebuilding and economic growth.

Across all of our three CAD divisions; CAD Architects, CAD Heritage and CAD Planning, we have been keenly anticipating this important update to the NPPF and we have been assessing the revised edition to advise our collective divisional thoughts.

Within CAD Heritage, a leading conservation architecture practice and heritage consultancy operating across Cornwall, Devon, Somerset and Dorset, we are interested to see how heritage policy has been substantially restructured, with significant changes to the terminology used to assess the effects of development on heritage-led assets.

For more on how these NPPF changes impact Architectural and Planning based projects, please see our respective CAD Architects & CAD Planning comments on the new NPPF via the following links:

CAD Architects National Planning Policy Framework Update

CAD Planning National Planning Policy Framework Update

Primary Policy Changes in the NPPF 2026

First, we will look at the main planning policy changes in the NPPF overall, before looking more closely at the changes directly relevant to conservation architecture and traditional buildings.

• Presumption for Sustainable Development: Development inside defined settlement boundaries receives strong in-principle support. The new framework recalibrates the within-settlements test under Policy S4, requiring approval unless adverse effects “substantially outweigh” the benefits. This sets a supportive policy starting point that sustainable development proposals should be approved without delay. “In all locations, development proposals that accord with both an up-to-date development plan and the decision-making policies in this framework should be approved without delay.”

Naturally we perceive a high degree of sustainability in the retention of historic buildings, structures and settlements. Reinforcing settlements and the expansion and infilling of settlements will be of particular benefit to landscape designations (such as World Heritage Sites), ensuring these settings can be carefully managed.

• Community Asset Protection: Adds new protections that include stringent proofs that a community asset such as a pub or music venue is not viable before allowing it to be converted or redeveloped.

With works affecting historic buildings and structures we are strong advocates of commercial viability. This change puts one of our key focus points on the radar at national level- commercial viability is integral to the long term benefit and maintenance of historic and listed buildings.

• Economic support: Provides stronger support for local high streets.

We believe this is long overdue, retaining the character and vibrancy of our traditional high streets and town centre cores are vital.  

Key Changes directly impacting Heritage and Conservation in the NPPF 2026

• Removal of “Less Than Substantial Harm”: The familiar phrase “less than substantial harm” has been removed altogether. Heritage assessments now evaluate impacts using a new framework categorized according to whether the impact delivers a positive effect, no effect, harm, substantial harm, or total loss.

For the first time, the NPPF also expressly describes substantial harm as occurring where development would “seriously affect a key element of a heritage asset’s significance,” making it vital to comprehensively assess all heritage asset elements at the outset.

• Positive Role for Heritage: Chapter 20 is restructured around a thematic approach that emphasizes supporting proposals with positive effects on the potential of heritage assets to drive sustainable redevelopment and growth, rather than simply measure degrees of harm. Positive development can repair historic fabric, bring buildings back into use, better reveal significance, improve settings and secure the long-term future of heritage assets. The new NPPF gives those outcomes a clearer place within the assessment.

• Redefining Public Benefits: The concept of “optimum viable use” has been omitted. Instead, the NPPF explicitly lists enabling energy-efficiency measures, low-carbon heating, and securing the long-term reuse of vacant or underused listed buildings as key public benefits.

This change does some way to improve high energy demands of historic buildings – a particular touch point for those involved within the rental sector targeting EPC levels between A-C, which in most cases are difficult to achieve within historic and listed buildings.

• Separation of Assets: The NPPF introduces dedicated policies for designated assets, non-designated assets, World Heritage Sites, conservation areas, and archaeological assets.

• Heritage Impact Assessments are expressly recognised. There is also a useful change in Annex C of the Framework. The national information requirement associated with HE5 is expressly identified as a Heritage Impact Assessment, comprising an assessment of the significance of the assets affected, including the contribution made by their setting, and the potential effects of the proposal on their significance. For applicants, this reinforces the importance of proportionate heritage assessment at an early stage of design.

We are pleased to see the launch of the new NPPF and the positive role it affords to conservation architecture and heritage-led assets. We look forward to helping our clients achieve continued success using this new framework as part of our justifications to enable alterations and development to traditional dwellings and heritage structures alike.

You can see the full updated NPPF here.

For more information about the NPPF and a no obligation discussion about your own conservation architecture or traditional building project, contact us today.

You can email us at info@cadheritage.co.uk or book a free consultation here.