Technical Advice Note (TAN) 15 - reflections, recommendations and advice
Following the publication of the Welsh Government’s new Technical Advice Note (TAN) 15, JBA Associate Director George Baker reflects on how the new policy will impact development and flood risk in Wales, the challenges it will raise, and the support we can provide.
On 31 March 2025, the Welsh Government released the first update to TAN 15 since its initial publication in 2004. The new TAN has come into immediate effect and applies to all planning applications registered after this date.
The updated technical advice note for Development, Flooding and Coastal Erosion was first released in December 2021 but was quickly withdrawn to allow for additional consultation. What then followed was a further draft and consultation from the Welsh Government in 2023. During this time, Local Planning Authorities were tasked with producing Strategic Flood Consequence Assessments (SFCA) based on the first release of the new TAN to support their Local Development Plans (LDPs). This process is something we were fortunate to support the vast majority of Welsh LPAs with, with most SFCAs being delivered on a regional basis.
Building on JBA recommendations
Having published an evaluation of TAN 15 in 2017, it is rewarding to see that the new TAN picks up on all of the recommendations we made (although we did not have a hand in writing the new TAN). Key recommendations from our review that have been implemented in the new policy include:
- Moving from a precautionary to a risk-based approach to decision making.
- Development of new risk-based flood mapping, recognising the advancements in flood risk mapping technology and climate change assessment.
- Strengthening the role of LDPs and SFCAs in plan-led decision making.
- Promotion of flood resilience in development.
- Updates to development vulnerability classifications.
- Incorporation of TAN 14 on coastal erosion into TAN 15.
Much of the negative feedback to the initial release of the TAN came from concerns that it would blight development in existing communities, preventing adaptation to climate change and sustainable development of brownfield sites, and work against the objectives of Future Wales: The National Plan. Additionally, Local Authorities felt that there were circumstances where a reasonable degree of flexibility was necessary to implement strategies to regenerate or revitalise existing settlements or to achieve key economic or environmental objectives.
The Welsh Government’s response has been to update the TAN with far greater nuance to a range of circumstances. This is most notable in the distinction between ‘new development’ and ‘redevelopment’. Far greater flexibility is given to redevelopment, which is defined as the development of Previously Developed Land. Conversely, Greenfield development in flood risk areas is strongly discouraged.
In addition, the Welsh Government have responded to Local Authority feedback in setting out LDP considerations for each flood zone. These considerations provide greater clarity to the potential scope and function of SFCAs and LDPs in strategically responding to flood risk, climate change and the need for sustainable development. Far more weight has been given to site allocation and the early assessment of flood risk for development proposals in flood risk areas.
Expert guidance to support you in negotiating the challenges of TAN 15
I welcome the release of the new TAN 15. It provides everyone with long-overdue clarity concerning development and flood risk in Wales. However, out of necessity, the TAN that has evolved over the last few years has become more complicated. Therefore, the document would have benefited from a focus on presenting and communicating the multi-faceted requirements of the new policy. Such efforts may have helped to head off a few of the gaps and inconsistencies in the policy that we are starting to come to terms with. We are, however, on hand to help our clients navigate their way through any such challenges.
Our knowledge, technology and appreciation of flood risk, climate change and resilience are moving at such a pace that I expect the next update to TAN15 will not take another 20 years to come about.
To find out more about the implications of TAN 15 and the support we can provide, please contact George Baker.
