Thorpe House School, 29 Oval Way, GERRARDS CROSS, SL9 8QA

Thorpe House School, 29 Oval Way, GERRARDS CROSS, SL9 8QA — Buckinghamshire Council - Chiltern Area * — Appeal Decision Site visit made on 3 July 2025 by K Reeves BA (Hons) MA MRTPI an Inspector appointed by the Secretary of State Decision date: 21 October 2025 Appeal Ref: APP/X0415/W/24/3358179 Thorpe House School, 29 Oval Way, Chalfont St Peter, Buckinghamshire SL9 8QA • The appeal is made under Section 78 of the Town and Country Planning Act 1990 (as amended) against a refusal to grant planning permission. • The appeal is made by Thorpe House School and Seriously Fun Swimming Schools against the decision of Buckinghamshire Council - East Area (Chiltern). • The application Ref is PL/23/3817/FA. • The development is change of use to allow non-school swimming lessons in the existing enclosed swimming pool. Decision 1. The appeal is dismissed. Preliminary Matters 2. During my site visit, the swimming pool was in use by an external organisation unaffiliated with the school, providing swimming lessons. On this basis, it is evident that the proposal has already been implemented. 3. A dispute has arisen between the main parties regarding the plans submitted during the application process.

Thorpe House School, 29 Oval Way, GERRARDS CROSS, SL9 8QA — Buckinghamshire Council - Chiltern Area * — Appeal Decision The appellants appear to have advised the Council at some stage that the originally proposed acoustic fence could not be constructed without compromising the structural integrity of the swimming pool. 4. The Council maintains that the acoustic fence was withdrawn from consideration and confirms that the application was determined on the understanding that no such fence would be installed. In contrast, the appellants assert that this element of the scheme was never formally withdrawn. 5. However, the precise sequence of events surrounding this disagreement is largely immaterial to my assessment of the appeal. The appellants have submitted amended plans as part of the appeal, which propose a revised acoustic fence around the swimming pool. This new design would be lower in height than the original proposal. 6. The revised acoustic fence would follow a slightly altered alignment, though not significantly different from the original. At 3.2 metres in height, it would be approximately 0.3 metres lower than the previously proposed fence. In relation to neighbouring properties, the visual impact of the amendments is minor and does not constitute a substantive change to the original proposal considered by the Council.

Thorpe House School, 29 Oval Way, GERRARDS CROSS, SL9 8QA — Buckinghamshire Council - Chiltern Area * — Appeal Decision https://www.gov.uk/planning-inspectorate

Thorpe House School, 29 Oval Way, GERRARDS CROSS, SL9 8QA — Buckinghamshire Council - Chiltern Area * — Appeal Decision https://www.gov.uk/planning-inspectorate Appeal Decision APP/X0415/W/24/3358179 7. The original fence proposal was subject to public consultation during the application process. Given the similar positioning and reduced height of the revised fence, interested parties have had the opportunity to comment on a scheme that closely resembles the one now before me. Additionally, the appeal timetable provided further opportunity for both the Council and interested parties to respond to the proposed amendments. I am therefore satisfied that no party has been prejudiced by the acceptance of the revised scheme. Main Issue 8. The main issue is the effect of the development on the living conditions of the occupiers of the neighbouring properties having regard to noise. Reasons 9. The appeal site comprises a swimming pool associated with a school. Originally constructed in the 1950s, the pool was granted planning permission in 2018 for the installation of a curved clear-panel enclosure. The current proposal seeks to permit use of the pool by an external organisation for the purpose of delivering swimming activities. 10.

Thorpe House School, 29 Oval Way, GERRARDS CROSS, SL9 8QA — Buckinghamshire Council - Chiltern Area * — Appeal Decision The proposed non-school use of the pool would be restricted to term-time only, operating Monday to Friday between 4.30pm and 7.30pm, and on Saturdays between 9.30am and 12.30pm. The pool would not be used for this purpose on Sundays or Bank Holidays. A maximum of 12 children would receive lessons at any one time, supervised by two instructors and supported by three additional staff members. 11. Although it has been acknowledged that there are no specific noise standards for assessing sound generated by swimming pools, the nature of the proposed use would result in noise emissions during early evenings and Saturday mornings. Given the low-density residential character of the surrounding area, ambient noise levels are relatively low. 12. Access to the appeal site is via an alleyway that runs adjacent to the boundary of a residential property. I recognise that this route may generate additional noise from individuals conversing while arriving at or departing from the site. However, such noise would be intermittent and short-lived. Consequently, any impact on residential amenity arising from pedestrian movement would be limited. 13.

Thorpe House School, 29 Oval Way, GERRARDS CROSS, SL9 8QA — Buckinghamshire Council - Chiltern Area * — Appeal Decision It is undisputed by the main parties that noise generated by the pool use affects nearby sensitive receptors. In response, the appellants have submitted a management plan aimed at curbing activities likely to produce excessive noise. Additionally, it is proposed that windows would remain closed, except when internal temperatures exceed 30°C, and only then would windows on the elevation of the enclosure facing away from residential properties be opened. 14. During my site visit, I observed that internal noise levels within the pool enclosure were significant. While the enclosure does provide some attenuation, it does not reduce noise to an acceptable level, as evidenced by the noise assessment conducted by Three Spires Acoustics Limited. To address this, the appellants propose the installation of an acoustic fence between the pool and neighbouring residential properties. https://www.gov.uk/planning-inspectorate 2

Thorpe House School, 29 Oval Way, GERRARDS CROSS, SL9 8QA — Buckinghamshire Council - Chiltern Area * — Appeal Decision Appeal Decision APP/X0415/W/24/3358179 15. The most recent noise survey submitted with the appeal includes measurements taken from boundary locations at 25 Oval Way and the nearest property on The Queensway. According to modelling by Three Spires Acoustics Limited, the installation of an acoustic fence with a superficial mass of 10kg/m² would yield a perceptible improvement in noise conditions at the affected receptors. 16. However, in their final comments, the appellants submitted technical specifications for the fence they intend to install. These specifications differ from those used in the noise survey report. While the revised details suggest the potential for improved noise mitigation, the survey was not based on the actual fence design now proposed. As a result, the precise impact of these differences remains unclear, introducing uncertainty regarding the effectiveness of the intended fence in achieving acceptable noise levels. 17. Given the sensitivity of the site and history of noise nuisance, it is essential that the proposal is rigorously assessed.

Thorpe House School, 29 Oval Way, GERRARDS CROSS, SL9 8QA — Buckinghamshire Council - Chiltern Area * — Appeal Decision In light of the uncertainty introduced by the revised fence details, I cannot be confident that the proposed fence would deliver the same or greater level of mitigation as indicated in the noise survey report. Accordingly, a cautious and robust approach to this aspect of the appeal is warranted. As such, it would not be reasonable to rely on a planning condition to ascertain the acoustic performance of the intended fence, particularly where such a mechanism is unlikely to involve public consultation. 18. For these reasons, without certainty around the proposed acoustic fence and its effectiveness, it has not been sufficiently demonstrated that the development would not have a materially harmful effect on the living conditions of the occupiers of the neighbouring properties, when having regard to noise.

Thorpe House School, 29 Oval Way, GERRARDS CROSS, SL9 8QA — Buckinghamshire Council - Chiltern Area * — Appeal Decision Consequently, the proposal conflicts with Policies GC3 and GC7 of the Chiltern District Local Plan 1997 (including alterations adopted 29 May 2001) Consolidated September 2007 and November 2011 (LP), insofar as they seek to protect the amenities enjoyed by the occupants of existing adjoining dwellings and prevent noise levels and/or noise characteristics that would result in an unacceptable degree of disturbance to the occupants of any residential or other noise-sensitive development in the vicinity of the application site. Other Matter 19. I acknowledge that the Council operates, and has granted permission for, swimming pool facilities that have significantly longer operational hours than I am considering through the appeal. However, those swimming pools would have different locational contexts that make a meaningful comparison with the appeal difficult. I also note that the nuisance abatement notice issued under the Environmental Protection Act 1990 did not require the erection of an acoustic fence, just a restriction on the operating hours.

Thorpe House School, 29 Oval Way, GERRARDS CROSS, SL9 8QA — Buckinghamshire Council - Chiltern Area * — Appeal Decision However, the prevention of public or statutory nuisance is not the same as the legitimate planning objective of safeguarding acceptable living conditions for neighbouring occupiers. Noise falling short of a public or statutory nuisance may nevertheless cause unacceptable harm to a neighbour’s living conditions. Planning Balance 20. The development increases the availability of swimming facilities for young children in the local area. The appellants explain that there is currently a deficiency of learner pool facilities in the local area. It makes more effective use of the https://www.gov.uk/planning-inspectorate 3

Thorpe House School, 29 Oval Way, GERRARDS CROSS, SL9 8QA — Buckinghamshire Council - Chiltern Area * — Appeal Decision However, the prevention of public or statutory nuisance is not the same as the legitimate planning objective of safeguarding acceptable living conditions for neighbouring occupiers. Noise falling short of a public or statutory nuisance may nevertheless cause unacceptable harm to a neighbour’s living conditions. Planning Balance 20. The development increases the availability of swimming facilities for young children in the local area. The appellants explain that there is currently a deficiency of learner pool facilities in the local area. It makes more effective use of the https://www.gov.uk/planning-inspectorate 3

Thorpe House School, 29 Oval Way, GERRARDS CROSS, SL9 8QA — Buckinghamshire Council - Chiltern Area * — Appeal Decision Appeal Decision APP/X0415/W/24/3358179 school’s existing facilities to improve the quality of service provision and promote healthy living, both of which are encouraged by the Framework. There is also the potential for the facilities to cater for children with mobility issues due to the small class sizes allowing one-on-one teaching and assistance. The appellants also point to the facilities aiding the local catchment area to meet the Government’s National Curriculum requirement relating to water safety. The cumulative benefits, taken together with the context of the apparent under provision of these facilities, would carry moderate weight as the small class sizes mean that the contribution the development would make to provision in the local area would be somewhat limited. 21. Weighing against the benefits is the conclusion that it has not been sufficiently demonstrated that the development does not have a materially harmful effect on the living conditions of the occupiers of the neighbouring properties, when having regard to noise, resulting in a conflict with Policies GC3 and GC7 of the LP.

Thorpe House School, 29 Oval Way, GERRARDS CROSS, SL9 8QA — Buckinghamshire Council - Chiltern Area * — Appeal Decision The proposal may comply with certain policies contained in the development plan, but given the harm that I have identified, the proposal conflicts with the development plan when taken as a whole. The Framework seeks to retain a high standard of amenity for existing residents. The aforementioned development plan policies are consistent with the Framework. The policy conflicts and the associated harm from the development therefore carry significant weight in the planning balance. 22. Overall, I find that the adverse impact of the development would outweigh the collectively moderate weight that can be attributed to the scheme’s benefits. Conclusion 23. For the reasons given above, the development conflicts with the development plan and the material considerations do not indicate that the appeal should be decided other than in accordance with it. Accordingly, the appeal should be dismissed.

Thorpe House School, 29 Oval Way, GERRARDS CROSS, SL9 8QA — Buckinghamshire Council - Chiltern Area * — K Reeves INSPECTOR https://www.gov.uk/planning-inspectorate 4