Carlyle Business centre, Gogmore Lane, Chertsey, KT16 9AP, KT16 9AP

Carlyle Business centre, Gogmore Lane, Chertsey, KT16 9AP, KT16 9AP — Runnymede Borough Council — by C Walker BA (Hons) DipTP MRTPI an Inspector appointed by the Secretary of State Decision date: 29 August 2025

Carlyle Business centre, Gogmore Lane, Chertsey, KT16 9AP, KT16 9AP — Runnymede Borough Council — Carlyle Business Centre, Gogmore Lane, Chertsey, Surrey KT16 9AP • The appeal is made under section 78 of the Town and Country Planning Act 1990 (as amended) against a refusal to grant approval required under Article 3(1) and Schedule 2, Part 3, Class MA of the Town and Country Planning (General Permitted Development) (England) Order 2015 (as amended). • The appeal is made by Mr M Kachmar of IMKO Premier Ltd against the decision of Runnymede Borough Council. • The application Ref is RU.24/1574. • The development proposed is described as prior notification requirement under Part MA of the GPDO for the change of use of Class E space to form 9 apartments.

Carlyle Business centre, Gogmore Lane, Chertsey, KT16 9AP, KT16 9AP — Runnymede Borough Council — Carlyle Business Centre, Gogmore Lane, Chertsey, Surrey KT16 9AP • The appeal is made under section 78 of the Town and Country Planning Act 1990 (as amended) against a refusal to grant approval required under Article 3(1) and Schedule 2, Part 3, Class MA of the Town and Country Planning (General Permitted Development) (England) Order 2015 (as amended). • The appeal is made by Mr M Kachmar of IMKO Premier Ltd against the decision of Runnymede Borough Council. • The application Ref is RU.25/0688. • The development proposed is described as prior notification requirement under Part MA of the GPDO for the change of use of Class E space to form 9 apartments.

Carlyle Business centre, Gogmore Lane, Chertsey, KT16 9AP, KT16 9AP — Runnymede Borough Council — Warning and Evacuation Strategy dated November 2024 were before the Council https://www.gov.uk/planning-inspectorate

Carlyle Business centre, Gogmore Lane, Chertsey, KT16 9AP, KT16 9AP — Runnymede Borough Council — Warning and Evacuation Strategy dated November 2024 were before the Council https://www.gov.uk/planning-inspectorate

Carlyle Business centre, Gogmore Lane, Chertsey, KT16 9AP, KT16 9AP — Runnymede Borough Council — Warning and Evacuation Strategy dated November 2024 were before the Council Appeal Decision APP/Q3630/W/25/3365693 and 3368331 at the time of determination. However, in the case of Appeal B, these documents were updated in May 2025, and also included details of a Dry Access Route (figure 3) with the Council determining the application on the basis of these. Both appeals now advance the May 2025 versions of the flood risk information for consideration. As these documents have been subject to consultation and do not make a substantive change to Appeal A, no party would be prejudiced by my acceptance of these documents. I therefore proceed on this basis and reference to the FRA hereafter, relates to the updated version. 5. The appeal schemes relate to prior approval notifications made under Article 3(1) and Schedule 2, Part 3, Class MA of the Town and Country Planning (General Permitted Development) (England) Order 2015 as amended (the GPDO). 6. Where an application is made for a determination as to whether prior approval is required for development, the local planning authority may refuse the application where it considers that the proposed development does not comply with the conditions, limitations or restrictions that are applicable to such permitted development.

Carlyle Business centre, Gogmore Lane, Chertsey, KT16 9AP, KT16 9AP — Runnymede Borough Council — Warning and Evacuation Strategy dated November 2024 were before the Council In this case, prior approval is required in respect of a number of matters, including the flooding risks in relation to the building. 7. The provisions of the GPDO do not require regard to be had to the development plan. Therefore, I have only had regard to the policies of the Runnymede 2030 Local Plan (adopted 2020) (Local Plan) and the National Planning Policy Framework (the Framework) in so far as they are a material consideration relevant to matters of flood risk. Main Issue 8. In light of the above, the main issue is the effect of the proposed development on flooding risks in relation to the building. Reasons 9. Comprising a commercial building, the appeal site is located on the corner of Gogmore Lane in Chertsey. The proposed scheme is a car free development for a total of 9 no. one and two-bedroom apartments. Pedestrian access to and from the building is proposed to be taken from the north and west entrance doors fronting onto Gogmore Lane. 10. The appeal site is located within Flood Zone 1, on what is described as a dry island. During a flood event the dry island would remain free from flooding itself, but would be surrounded entirely by land at a higher risk of flooding, within Zones 2 and 3. 11.

Carlyle Business centre, Gogmore Lane, Chertsey, KT16 9AP, KT16 9AP — Runnymede Borough Council — Warning and Evacuation Strategy dated November 2024 were before the Council Amongst other things, Policy EE13 of the Local Plan sets out that when a site is located on a dry island, applicants will be expected to consider the onset and duration of a flood, the vulnerability and willingness of occupiers to evacuate the site in a flood event and the ability of the site to operate an effective flood evacuation procedure. 12. The Runnymede Borough Council Strategic Flood Risk Assessment (SFRA) (2018) is clear that during a flood event, properties within a dry island could be affected by loss of key services and by being surrounded by deep flood water. In this context, the development must demonstrate that it would be safe for its https://www.gov.uk/planning-inspectorate 2

Carlyle Business centre, Gogmore Lane, Chertsey, KT16 9AP, KT16 9AP — Runnymede Borough Council — Warning and Evacuation Strategy dated November 2024 were before the Council Amongst other things, Policy EE13 of the Local Plan sets out that when a site is located on a dry island, applicants will be expected to consider the onset and duration of a flood, the vulnerability and willingness of occupiers to evacuate the site in a flood event and the ability of the site to operate an effective flood evacuation procedure. 12. The Runnymede Borough Council Strategic Flood Risk Assessment (SFRA) (2018) is clear that during a flood event, properties within a dry island could be affected by loss of key services and by being surrounded by deep flood water. In this context, the development must demonstrate that it would be safe for its https://www.gov.uk/planning-inspectorate 2

Carlyle Business centre, Gogmore Lane, Chertsey, KT16 9AP, KT16 9AP — Runnymede Borough Council — Warning and Evacuation Strategy dated November 2024 were before the Council Appeal Decision APP/Q3630/W/25/3365693 and 3368331 lifetime, taking account of the vulnerability of its users and the need for safe access and escape routes during a flood event. 13. The SFRA sets out that a safe access/egress route should allow occupants to safely enter and exit buildings and be able to reach land outside of the flooded area, without the intervention of emergency services or others during flood conditions, including climate change allowances. It also sets out that it is acceptable for access/egress routes to be wet in Runnymede so long as the flood hazard is no greater than ‘Very Low Hazard – Caution’ along the full length of the access/escape route. The route should also be along publicly accessible roads or paths. 14. The above policy context and mitigation expectations are broadly consistent with the Framework. This states that development should only be allowed in areas at risk of flooding where safe access and escape routes are included where appropriate, as part of an agreed emergency plan. National Planning Policy Guidance (NPPG) further guides that access routes should enable occupants to safely access and exit their dwellings during design flood conditions. 15.

Carlyle Business centre, Gogmore Lane, Chertsey, KT16 9AP, KT16 9AP — Runnymede Borough Council — Warning and Evacuation Strategy dated November 2024 were before the Council It is common ground that the appeal building itself is not at risk from flooding in all modelled scenarios. However, the proposed use would increase the flood risk from ‘less vulnerable’ to ‘more vulnerable’ as categorised by the Framework. 16. The FRA accompanying these appeals references the relatively recent River Thames (Datchet to Teddington) Modelling and Mapping Study carried out in 2023, a fluvial model (the model). The FRA establishes that during a design flood event, the surrounding area, including all main access roads, would be flooded. 17. At approximately 908m in length, the proposed flood evacuation route extends for a considerable distance from the site in order to reach land outside the flooded area. It is shown to extend east along Gogmore Lane, south along Guildford Street/Heriot Road (B375), west along the A317 (Pycroft Road) and then south along the A320 Bell Bridge Road. This would require occupants to take a rather convoluted path, crossing roads multiple times to avoid areas of flood water with higher hazard ratings.

Carlyle Business centre, Gogmore Lane, Chertsey, KT16 9AP, KT16 9AP — Runnymede Borough Council — Warning and Evacuation Strategy dated November 2024 were before the Council This could be difficult for individuals to navigate, alongside having to judge different flood depths and consider unseen dangers such as possible debris in the water, and/or contaminants. 18. While a large part of the route has a low hazard rating of ‘Caution to People’, the appellant acknowledges that around 80m of the route comprises a hazard rating of ‘Dangerous to Some’. According to the appellants own evidence, based on topographical information, the depths of road flooding in places could be up to a predicted 0.39m1, which exceeds the acceptable level (0.25m) set out in the SFRA. 19. Furthermore, the evacuation route takes occupants near to areas with a hazard rating of ‘Danger for Most’. Therefore, occupants could easily deviate slightly from the route and find themselves in an area of greater flood risk. There is also a risk associated with having two access points to the building itself from Gogmore Lane. This could add to the confusion for occupants, particularly in a stressful situation, as to which direction to take in the first instance. Proceeding south from the main 1 According to the letter dated 26 June 2025 from Herrington Consulting to the Council following the decision notice to Appeal B.

Carlyle Business centre, Gogmore Lane, Chertsey, KT16 9AP, KT16 9AP — Runnymede Borough Council — Warning and Evacuation Strategy dated November 2024 were before the Council https://www.gov.uk/planning-inspectorate 3

Carlyle Business centre, Gogmore Lane, Chertsey, KT16 9AP, KT16 9AP — Runnymede Borough Council — Warning and Evacuation Strategy dated November 2024 were before the Council https://www.gov.uk/planning-inspectorate 3 Appeal Decision APP/Q3630/W/25/3365693 and 3368331 entrance along Gogmore Lane for example, is likely to result in occupants encountering unexpected flood waters. 20. The appellant asserts that the ground level along Guildford Street is higher than the ground level determined by LIDAR from the model and thus the flood depths and flood hazard rating would be less than set out in the model. However, the Council caution against relying on this, as the Environment Agency flood modelling has not been re-run which they say means the appellant has over-simplified the local flood dynamics. 21. As I cannot be certain whether higher ground levels would displace floodwater elsewhere and this could have knock on effects for flood velocity and depth, I am not satisfied that the proposed evacuation route can be considered as safe or reliable during a design flood event. Furthermore, during an exceedance event, the evacuation route would be inundated and have a hazard classification of ‘significant’ meaning the flooding to roads within the evacuation route would be dangerous to most people. 22.

Carlyle Business centre, Gogmore Lane, Chertsey, KT16 9AP, KT16 9AP — Runnymede Borough Council — Warning and Evacuation Strategy dated November 2024 were before the Council The appellant estimates it would take floodwater approximately 9.5 days in a design flood event (or 4 days in an exceedance event) before reaching Guildford Street and therefore, residents would have sufficient time to evacuate the site before water reaches the access route. 23. However, I agree with the findings of an Inspector who dealt with a similar appeal2 in the borough that I have been referred to in this regard. It is unlikely that occupants of the proposed development would leave their homes at such an early stage. This is because of the potential for flooding to ultimately not occur/subside, and/or because it is unlikely that the residents’ own properties would be flooded. I therefore do not consider that having future residents sign up to the Environment Agency’s flood warning system, as has been advocated, together with the evacuation plan to persuade residents to leave the site at an early opportunity, would provide a suitable level of mitigation from flood risk. 24. Whilst residents could choose to remain on site during a flood event, evidence suggests that the River Thames floods can last for extended periods, over a matter of weeks.

Carlyle Business centre, Gogmore Lane, Chertsey, KT16 9AP, KT16 9AP — Runnymede Borough Council — Warning and Evacuation Strategy dated November 2024 were before the Council This would increase the risk of occupants placing an additional burden on the emergency services, such as having to deal with any medical emergencies. Additionally, key local infrastructure such as water treatment works and electricity substations may be impacted by flooding, potentially rendering residences uninhabitable. Furthermore, facilities within the dry island may not be available to occupants as these could be affected by flooded infrastructure and the ability of staff to reach them. 25. Either way, occupants remaining on site or navigating a potentially treacherous evacuation route could lead to additional pressure being placed on the emergency response efforts during times of flood. Conclusions 26. In conclusion, introducing additional apartments within this dry island would place additional residents at risk during a flood event and place greater pressure on emergency services. Whilst there may still be some facilities that could be utilised 2 APP/Q3630/W/24/3349839 https://www.gov.uk/planning-inspectorate 4

Carlyle Business centre, Gogmore Lane, Chertsey, KT16 9AP, KT16 9AP — Runnymede Borough Council — Warning and Evacuation Strategy dated November 2024 were before the Council Appeal Decision APP/Q3630/W/25/3365693 and 3368331 during a flood event within the Chertsey dry island, this does not negate the need for a safe evacuation route. 27. Accordingly, I do not find the proposals suitable having regard to flooding risks in relation to the appeal building. Consequently, for the above reasons and having regard to conditions MA.2.(2)(c) and MA.2.(4) of Class MA, Part 3, Schedule 2 of the GPDO and paragraph W of Part 3, Schedule 2 of the GPDO, prior approval is required and should not be granted for either appeal. 28. Insofar as they are relevant, the proposal would also conflict with Policy EE13 of the Local Plan, the related provisions of the SFRA, and the aims of the Framework, in respect of managing flood risk for new developments.

Carlyle Business centre, Gogmore Lane, Chertsey, KT16 9AP, KT16 9AP — Runnymede Borough Council — C Walker INSPECTOR https://www.gov.uk/planning-inspectorate 5