ID House, Vanwall Road, Maidenhead, Berks, SL6 4UB

ID House, Vanwall Road, Maidenhead, Berks, SL6 4UB — Royal Borough of Windsor and Maidenhead — Appeal Decision Site visit made on 24 July 2025 by G Sibley MPLAN MRTPI an Inspector appointed by the Secretary of State Decision date: 28th October 2025 Appeal Ref: APP/T0355/W/25/3360438 ID House, Vanwall Road, Maidenhead SL6 4UB • 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 Mr H Schneck of Mountley Ltd against the decision of the Council of the Royal Borough of Windsor and Maidenhead. • The application Ref is 24/02651. • The development proposed is conversion of part of the GF building from Class E to form 1 flat. Decision 1. The appeal is dismissed. Main Issues 2. The main issues relevant to this appeal are: • the effect of the proposal upon the Vanwall Business Park with regard to the loss of employment floorspace • the effect of the proposal on the living conditions of the occupiers of the proposed flat with regard to light, ventilation and outdoor amenity space; and • whether suitable measures would be included to adapt to and mitigate the effects of climate change. Reasons Employment Floor Space 3.

ID House, Vanwall Road, Maidenhead, Berks, SL6 4UB — Royal Borough of Windsor and Maidenhead — Appeal Decision The appeal building is located within Vanwall Business Park, designated a business area under Policy ED2 of the Borough Local Plan 2013-2033 (BLP), adopted 2022. The policy states that for all sites a nil net loss of commercial floor space will apply. Policy ED3 of the BLP then sets out that where a change of use is proposed from an economic use to another use, development proposals must provide credible and robust evidence of an appropriate period of marketing for economic use and that the proposal would not cause unacceptable harm to the local economy. 4. Although prior approvals have been granted, both by the Council and on appeal, for the residential conversion of the building, there is no substantive evidence that either has been implemented or that substantial works have taken place to physically alter the building and show clear progress towards the new use. Accordingly, for the purposes of this appeal, the building is considered to be in employment use despite appearing vacant at the time of my site visit. https://www.gov.uk/planning-inspectorate

ID House, Vanwall Road, Maidenhead, Berks, SL6 4UB — Royal Borough of Windsor and Maidenhead — Appeal Decision Appeal Decision APP/T0355/W/25/3360438 5. Neither substantive evidence that the existing economic use has been marketed or an assessment considering the impact that this development would have on the local economy has been provided as required by Policy ED3. 6. While the proposal relates to a relatively small part of the building, its location within a designated business area means the site contributes positively to the local economy. The loss of this employment floorspace would therefore be harmful and contrary to the objectives of Policies ED2 and ED3. 7. Therefore, the proposed development would conflict with Policies ED2 and ED3 of the BLP. These expect, amongst other matters, that there would be a nil net loss of commercial floor space within the business area and that changes of use should be supported by credible and robust evidence, which would not be the case in this instance. Living Conditions 8. The development before me relates to the conversion of part of the existing building to residential use. While planning permission may have been granted for the building to be converted, there is no clear evidence that those permissions have been implemented.

ID House, Vanwall Road, Maidenhead, Berks, SL6 4UB — Royal Borough of Windsor and Maidenhead — Appeal Decision Accordingly, I have assessed the current proposal in the context of the building’s existing layout. 9. While the appellant has submitted a Daylight Assessment letter at appeal stage, I note the Council’s concern regarding its timing and consistency with previously approved external alterations, particularly to the elevation where the proposed flat would be situated. However, it is not evident that this permission has been implemented nor is there surety that it would be. As such, I have considered this evidence in the context of the existing building layout and other material before me. 10. The proposed unit would be single aspect, featuring a large window on the western elevation. However, the Daylight Assessment letter indicates that the proposed flat would achieve internal illuminance levels exceeding the recommended thresholds set out in Appendix C of BR209 (2022), using both default and revised reflectance values. 11. Although the Borough Wide Design Guide (Design Guide) encourages dual aspect accommodation, the size and layout of the flat, combined with the size and location of the proposed window, would provide adequate levels of natural light and ventilation.

ID House, Vanwall Road, Maidenhead, Berks, SL6 4UB — Royal Borough of Windsor and Maidenhead — Appeal Decision In this context, despite deviation from the Design Guide, the proposal would not have an unacceptable effect on the living conditions of future occupiers. 12. The proposal does not include private outdoor amenity space contrary to the guidance in the Design Guide. However, the site is located within a modest walking distance of Desborough Park, a substantial area of public open space. Although the proposal does not fully accord with the Design Guide, the availability of nearby public amenity space would ensure the future occupiers would have access to sufficient outdoor provision, in this instance. As such, the absence of private amenity space would not have an unacceptable effect on the future occupiers living conditions. 13. I therefore conclude that the proposed development would not result in unacceptable harm to the living conditions of future occupiers. Consequently, the development would broadly comply with Policy QP3 of the BLP insofar as it expects developments to provide sufficient levels of high quality private and public amenity https://www.gov.uk/planning-inspectorate 2

ID House, Vanwall Road, Maidenhead, Berks, SL6 4UB — Royal Borough of Windsor and Maidenhead — Appeal Decision Appeal Decision APP/T0355/W/25/3360438 space and to have no unacceptable effect on matters such as light and access to sunlight and daylight. Climate Change 14. Policy SP2 of the BLP requires all developments to demonstrate how they have been designed to incorporate measures to adapt to and mitigate climate change. It refers to, amongst other matters, the Sustainable Design and Construction Supplementary Planning Document, or successor documents, for further guidance. This has now been superseded by the Sustainability Supplementary Planning Document (SSPD) which is a material consideration. 15. Policy SP2 does not specify targets or standards, however, the SSPD seeks to secure a contribution to the Council’s carbon offset fund where developments have demonstrated that net zero cannot be achieved. The SSPD identifies an initial price of carbon offsets per tonne over a 30-year lifetime of the development. 16. Policy SP2 does not specify that net zero must be achieved.

ID House, Vanwall Road, Maidenhead, Berks, SL6 4UB — Royal Borough of Windsor and Maidenhead — Appeal Decision Furthermore, the Planning Practice Guidance (PPG) states that policies for planning obligations should be set out in plans and examined in public and that it is inappropriate to set out formulaic approaches to obligations in Supplementary Planning Documents (SPD), as these would not be subject to examination and SPDs should not add unnecessarily to the financial burdens on development. The requirement for the planning obligation is set out in the SSPD and not within a BLP policy and it has not been, based on the information before me, subject to independent examination or viability checks. Whilst the SSPD can encourage developers to exceed current policy and seek to provide net zero carbon emissions, it should not introduce new compulsory targets. 17. For the reasons given above, the contribution towards the carbon offset fund would not meet the tests set out in the National Planning Policy Framework (the Framework) and Regulation 122 of the Community Infrastructure Regulations 2010 (as amended). 18. The submitted Energy Statement sets out measures that would provide improved energy efficiency. A condition could be used to secure the delivery of the measures specified.

ID House, Vanwall Road, Maidenhead, Berks, SL6 4UB — Royal Borough of Windsor and Maidenhead — Appeal Decision As a result, it is evident that climate change adaptation and mitigation has been duly considered in accordance with Policies SP2 and EP1 of the BLP. Planning Balance and Conclusion 19. As previously noted, prior approvals have been granted, both by the Council and on appeal, for the conversion of the building to residential use. The area subject to this appeal was identified as a cycle store within those approved schemes. Additionally, planning permission has been granted for a separate outbuilding on the wider site intended to accommodate cycle and refuse storage, which the appellant contends would replace the internal provision. While these approvals suggest a theoretical fallback position, the appeal proposal would occupy the space designated for cycle storage in both fallback schemes. 20. The conditions attached to both prior approvals require that no part of the development shall be occupied until covered and secure cycle parking facilities have been provided in accordance with the approved plans. The appeal proposal would prevent compliance with these conditions with the flat proposed in the same location as https://www.gov.uk/planning-inspectorate 3

ID House, Vanwall Road, Maidenhead, Berks, SL6 4UB — Royal Borough of Windsor and Maidenhead — Appeal Decision Appeal Decision APP/T0355/W/25/3360438 the designated cycle storage area. Consequently, the proposed development would be in direct conflict with the approved plans and associated planning conditions. 21. Although the appellant refers to the approved outbuilding as a replacement facility, no evidence has been submitted to demonstrate how the fallback schemes and this proposal could be implemented in a manner that satisfies the relevant conditions. This unresolved conflict undermines the credibility of the fallback position and casts doubt that there is a real prospect of implementation. I therefore attribute this matter no weight in the planning balance. 22. The Council’s BLP was adopted in the last five years. Therefore, the assessment of the Borough’s 5-year housing land supply position is based on the housing requirements set out in the BLP. Accordingly, paragraph 11d) of the Framework is not engaged. 23. The proposal would deliver a single residential unit in a sustainable location and would reuse part of an existing building. Energy efficiency measures are proposed, and the scheme would make a modest contribution to housing supply.

ID House, Vanwall Road, Maidenhead, Berks, SL6 4UB — Royal Borough of Windsor and Maidenhead — Appeal Decision Whilst this relates to a single residential unit I afford moderate weight to these benefits, consistent with the Framework’s support for small and medium sites. 24. The Framework identifies that substantial weight should be attributed to the use of suitable brownfield land within settlements for homes. However, for the reasons given above, the site is not suitable, and the scheme would not comply with the Framework in this regard. Additionally, it has not been substantiated that land supply is constrained in the Borough. 25. The proposal would result in a loss of employment floorspace within a designated business area, contrary to relevant development plan policies. Policies ED2 and ED3 of the BLP are consistent with the Framework’s objective to support a strong and responsive economy through the protection of employment land as well as to not undermine key economic sites. Although the scale of the development is limited and thus the loss of employment space limited, given the long-lasting nature of such effects, I attribute significant weight to this harm. 26. In conclusion, the benefits of the proposed development would be outweighed by the identified harm, particularly the conflict with employment land policies.

ID House, Vanwall Road, Maidenhead, Berks, SL6 4UB — Royal Borough of Windsor and Maidenhead — Appeal Decision The proposed development conflicts with the development plan as a whole and the material considerations, including the Framework, do not indicate that the appeal should be determined other than in accordance with it. Therefore, for the reasons given above, I conclude that the appeal should be dismissed.

ID House, Vanwall Road, Maidenhead, Berks, SL6 4UB — Royal Borough of Windsor and Maidenhead — G Sibley INSPECTOR https://www.gov.uk/planning-inspectorate 4