Stables North Of Thornham Farm House , Prinsted Lane , Prinsted Southbourne, West Sussex, PO10 8HS

Stables North Of Thornham Farm House , Prinsted Lane , Prinsted Southbourne, West Sussex, PO10 8HS — Chichester District Council — Appeal Decision Site visit made on 29 May 2025 by S Harley BSc(Hons) M.Phil MRTPI ARICS an Inspector appointed by the Secretary of State Decision date: 13 June 2025 Appeal Ref: APP/L3815/W/25/3358934 Stables North of Thornham Farm House, Prinsted Lane, Prinsted, Southbourne, West Sussex, PO10 8HS • 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 Abbey Property Management Ltd., against the decision of Chichester District Council. • The application Ref is SB/22/01941/FUL. • The development proposed is conversion works to an existing stables and outbuildings to create a separate dwelling with fully engineered floating floor, retained stables, garage, and machinery store. Decision 1. The appeal is dismissed. Preliminary Matters 2. The National Planning Policy Framework (the Framework) was revised in December 2024. References in this decision are to the revised version. 3. The site is within the Chichester Harbour Area of Outstanding Natural Beauty, which is now known as the Chichester Harbour National Landscape (the CHNL). The statutory purpose of National Landscapes is to conserve and enhance the natural beauty of the area.

Stables North Of Thornham Farm House , Prinsted Lane , Prinsted Southbourne, West Sussex, PO10 8HS — Chichester District Council — Appeal Decision Section 85 of the Countryside and Rights of Way Act 2000 as amended by section 245 of the Levelling Up and Regeneration Act 2023 strengthens the duty on relevant authorities to "seek to further" the statutory purposes of protected landscapes including the CHNL. This replaces the former duty of "have regard to". The Framework requires that great weight should be given to conserving and enhancing landscape and scenic beauty in National Landscapes which have the highest status of protection in relation to these issues. 4. Chichester Harbour Conservancy has statutory responsibility for the CHNL. Policy 2 of the Chichester Harbour AONB Management Plan 2024-2025 (the Management Plan); and Policies 8 and 9 of the Chichester Local Plan: Key Policies 2014-2029 (LP) seek to conserve, to promote and to reinforce local distinctiveness and the natural beauty of the CHNL. 5. Work has progressed significantly on the Emerging Chichester Local Plan 2021 – 2039. Subject to consultation responses on the Main Modifications it is anticipated the Emerging LP will be adopted summer 2025. Its Policies therefore carry some weight although the wording might still change. https://www.gov.uk/planning-inspectorate

Stables North Of Thornham Farm House , Prinsted Lane , Prinsted Southbourne, West Sussex, PO10 8HS — Chichester District Council — Appeal Decision Appeal Decision APP/L3815/W/25/3358934 6. During the course of this appeal the appellant submitted a Unilateral Undertaking (UU) pursuant to section 106 of the Town and Country Planning Act 1990. I return to this below. 7. The buildings were granted planning permission in 2014 and were conditioned to be used in association with the adjacent Thornham Farm House (now identified as Thornham House). The stables have been sold separately and there are some indications from third Parties that stable uses did not commence. The appellant asserts the building has a “nil” use. At the time of my site visit items were stored in parts of the building. It is not for me in this appeal to address the lawful use of the site: this is a matter for the appellant and the Council. 8. The proposal was amended a number of times during the course of the planning application. Paragraph 1.8 of the Appeal Statement of Case states “Please note the determined roof plan is actually referenced 2394-PP-002 Rev A; the location plan is 2394 -004 Rev F; site plan is 2394 -003 Rev D. All other plans in the informative are correctly referenced”.

Stables North Of Thornham Farm House , Prinsted Lane , Prinsted Southbourne, West Sussex, PO10 8HS — Chichester District Council — Appeal Decision The Design and Access Statement dated July 2022 pre- dates some of the plans on which the Council determined the application. The determined plans show one bedroom, bathroom and dressing room on a sleeping platform above ground floor with a void below; disabled access may no longer be suitable; and roof openings are proposed. I have determined the appeal on this basis. 9. The appellant considers some of the works proposed may not be development as much would take place within the building. However, in my judgement, the type and extent of these, which are described in more detail below, amount to alterations, building, engineering and/or other works which would fall within the definition of development in Section 55 of the Town and Country Planning Act 1990. In any case, they form part of the scheme for which planning permission is sought. Main Issues 10.

Stables North Of Thornham Farm House , Prinsted Lane , Prinsted Southbourne, West Sussex, PO10 8HS — Chichester District Council — Appeal Decision The main issues are: whether or not the site is a suitable location for a dwelling taking into account local and national planning policies and access to services and facilities; whether or not adequate provision would be made for the safety of future occupiers of the building in the event of flooding; and the effect of the proposal on the character and appearance of the area including on the CHNL. Reasons Location 11. The appeal site is between Prinsted and Emsworth outside any defined settlement boundary. It is also within Tidal Flood Zone 3. Policy 2 of the LP; Emerging Policy S2 and Policy SB1 of the Southbourne Parish Neighbourhood Plan 2023 (the NP) seek to direct development to the most sustainable locations in accordance with the settlement hierarchy. The appeal site is within the Rest of Plan Area (countryside and small villages and hamlets with poor access to services), the lowest tier of the hierarchy. 12. I acknowledge the presence of the stables but this does not demonstrate an essential need for an open market dwelling in the countryside location because such a use can be more sustainably accommodated in, or adjacent to, existing settlements.

Stables North Of Thornham Farm House , Prinsted Lane , Prinsted Southbourne, West Sussex, PO10 8HS — Chichester District Council — Appeal Decision Nor would the proposal meet an essential local rural need or support https://www.gov.uk/planning-inspectorate 2

Stables North Of Thornham Farm House , Prinsted Lane , Prinsted Southbourne, West Sussex, PO10 8HS — Chichester District Council — Appeal Decision Nor would the proposal meet an essential local rural need or support https://www.gov.uk/planning-inspectorate 2 Appeal Decision APP/L3815/W/25/3358934 rural diversification. The fact of an existing building does not affect this. Accordingly, the proposal would conflict with the development strategy as set out in the above Policies and key Principle of PP06 of the Management Plan. 13. Policies 45 and 46 of the LP and Emerging Policy NE10, which contains similar criteria, allow for sustainable development in the countryside in certain circumstances. 14. Due to the distance from facilities; the narrow and curving Prinsted Lane; and the lack of bus services; the site is not particularly well located with regard to access to day to day services and facilities without reliance on the private vehicle. I consider it unlikely that future occupiers would commonly choose to walk or cycle to the closest services and facilities, especially during periods of darkness or during inclement weather, but would rely on the private vehicle for access to day to day services and facilities. In that respect the proposal would not be sustainable development.

Stables North Of Thornham Farm House , Prinsted Lane , Prinsted Southbourne, West Sussex, PO10 8HS — Chichester District Council — Appeal Decision Although not isolated it is not well related to a farmstead or group of buildings, as the only close building is Thornton House, and it is not close to an established settlement as it is separated from Prinsted village by agricultural land. Therefore, the proposal would does not garner support from the exception at Policy 45(1) of the LP. 15. The proposal would make use of an existing building and Policy 46 of the LP, subject to criteria, allows for changes of use of buildings in the countryside. The building is a relatively recent timber building on a concrete strip foundation overlain by a 150mm thick oversite concrete slab. Although undoubtedly well-constructed for its original purpose as stables, and in appropriate timber cladding, it is not of particular architectural or historic merit (Criterion 5). Detailed drawings or calculations have not been provided but the Parties generally accept that the existing building is in good structural condition. It seems likely that the building would be suitable for some uses, including employment, without the need for significant extension, alteration or re-building (Criterion 1). 16.

Stables North Of Thornham Farm House , Prinsted Lane , Prinsted Southbourne, West Sussex, PO10 8HS — Chichester District Council — Appeal Decision The Flude Property Consultants letter dated 28 March 2025 provides a brief analysis of the expected costs and income for alternative uses of the building. This concludes that use as an office, live/work unit or tourist accommodation would be unviable. However, this relies on including the estimated costs of the installation of the barge, as mitigation in the event of a flood, and it is not clear that this extent of works would be necessary for an office or other employment related activity where occupiers would not be sleeping. Nor is it clear what allowance has been made for the parking area and other buildings that are also part of the site. I cannot therefore confidently conclude that economic uses are unviable. 17. Moreover, no similar estimates have been provided for the likely value of a one bedroomed property, with disproportionately large non-sleeping accommodation, compared to the likely costs and difficulties associated with constructing the proposed flood mitigation measures. Nor is it clear why a one bedroom property would be more viable than a live/work property.

Stables North Of Thornham Farm House , Prinsted Lane , Prinsted Southbourne, West Sussex, PO10 8HS — Chichester District Council — Appeal Decision I find there is conflict with Policy 46(2) of the LP and Principle PP06 of the Management Plan in that it has not been satisfactorily demonstrated that other uses are not viable. 18. For the above reasons I conclude that the site is not a suitable location for a dwelling in terms of strategic planning policies or access to services and facilities. In these respects the proposal would conflict with Policies 2, 45(1) and https://www.gov.uk/planning-inspectorate 3

Stables North Of Thornham Farm House , Prinsted Lane , Prinsted Southbourne, West Sussex, PO10 8HS — Chichester District Council — Appeal Decision I find there is conflict with Policy 46(2) of the LP and Principle PP06 of the Management Plan in that it has not been satisfactorily demonstrated that other uses are not viable. 18. For the above reasons I conclude that the site is not a suitable location for a dwelling in terms of strategic planning policies or access to services and facilities. In these respects the proposal would conflict with Policies 2, 45(1) and https://www.gov.uk/planning-inspectorate 3

Stables North Of Thornham Farm House , Prinsted Lane , Prinsted Southbourne, West Sussex, PO10 8HS — Chichester District Council — Appeal Decision Appeal Decision APP/L3815/W/25/3358934 46(2) and (5) of the LP, Emerging Policy NE10, Policy SB1 of the NP and Principle PP06 of the Management Plan. Safety in the event of flooding 19. Tidal Flood Zone 3 is an area of highest risk of flooding, and has a 1 in 200 or greater annual probability of sea flooding. National and local planning policy seeks to avoid inappropriate development in the flood plain and to direct development away from areas of highest risk although Footnote 62 to Paragraph 176 of the Framework exempts some changes of use, including the conversion of a building to a dwelling, from the sequential test. There are no formally recorded incidents of historic flooding near or on the site, and a site specific Flood Risk Assessment accompanies the proposal. The evidence indicates that the site is some 2.75 AOD. To deal with potential tidal flood water inundation of some 5.0m an engineered floor with a floating barge structure would be installed that would enable the proposed habitable area to float upwards on a tidal flood event, mimicking a floating, permanently moored, houseboat. 20. To achieve this the existing L shaped building would be severed into two.

Stables North Of Thornham Farm House , Prinsted Lane , Prinsted Southbourne, West Sussex, PO10 8HS — Chichester District Council — Appeal Decision A stepped “mounting block” would be built on the courtyard side of the north wing of the building. Eleven steel columns with guides for roller bearings would be inserted to hold the building in place laterally against wind loads. These would be lowered through holes formed in the roof into prepared holes in the ground slab and secured in position by backfilling the hole with concrete and injecting resin into the ground to stabilise the soil around the steel posts. 21. Steel channel sections would be screwed to the inside face of the external walls of the building some 500mm above the existing concrete slab. The bottom metre of the internal cross walls would be removed to allow 3.3m pre-fabricated sections of a steel barge to be placed on rails and hydraulically pulled into the building. These would be welded together to form a watertight structure within the building. The cross walls would be reinstated after the barge was installed. 22. Roller bearings installed into the guides would allow the barge to rise as the water level increases. Small weep holes drilled at the bottom of the external walls would allow water to flow evenly beneath the barge as tide levels rise and water pressure would lift the barge structure.

Stables North Of Thornham Farm House , Prinsted Lane , Prinsted Southbourne, West Sussex, PO10 8HS — Chichester District Council — Appeal Decision At a depth of some 180mm flood water would start to lift the barge so that it would engage onto the channels fixed to the inside of the outer wall, and when it reaches 820mm, it would begin to lift the building and continue doing so during the flood event. As water recedes, the building would return to its original position. The structure would be fitted with a drift net skirt for purposes of preventing entry of debris below the building when it is floated. 23. The barge platform would not be attached to any part of the building. The only time they connect would be when the barge began to lift the building. Occupants of the building would be above the water level. 24. The appellant asserts there would be no operating mechanisms that would fail and prevent the barge from floating on a flood tide and that the holes in the structure for the insertion of the columns could easily be reinstated. However, the extent of demolition of the existing fabric, in terms of holes in the roof that would avoid damage to the specialist designed roof structures, and to the concrete floor and foundations, is not clear. There would be a new inner wall around the whole of the https://www.gov.uk/planning-inspectorate 4

Stables North Of Thornham Farm House , Prinsted Lane , Prinsted Southbourne, West Sussex, PO10 8HS — Chichester District Council — Appeal Decision Appeal Decision APP/L3815/W/25/3358934 building and a new floor. In my judgement, the proposed works would be of significant extent that would go well beyond the criteria of Policy 46(1) of the LP. It seems more than likely that the cost of the works and the difficulty of implementing them would mean that conversion would be impractical which could lead to pressure to demolish and re-build. 25. As reported in the Officer Report, the Environment Agency, in the response dated 19 December 2023, no longer object subject to a number of conditions. The most critical of these is the requirement that sleeping accommodation should be at first floor level or above. The single bedroom on a platform raised some 2.4m above existing ground level would meet the height above AOD requirements. However, the ground floor plans show a very large area of non-sleeping accommodation including a void beneath the sleeping platform which would create a very unusual dwelling.

Stables North Of Thornham Farm House , Prinsted Lane , Prinsted Southbourne, West Sussex, PO10 8HS — Chichester District Council — Appeal Decision To enforce the requirement of no sleeping accommodation at ground floor level would require overly intrusive inspections to the extent that, in my judgement, such a condition would not meet the reasonable or enforceability tests of the Framework and the Planning Practice Guidance (the PPG). 26. The site is within a Flood Warning Area with alerts typically raised 5 days before a predicted flood event. The Flood Risk Assessment and the Emergency Flood Plan do not demonstrate that safe access or escape routes would be available outside areas at risk of flooding: rather the intent is that occupants would remain in the building. However, there is little information about how quickly tidal flood water might rise or abate or how occupants could safely enter or exit the building whilst it was rising/raised should this be necessary, for example in an emergency. This would present a risk to health and safety of additional residents within a known flood risk area. 27.

Stables North Of Thornham Farm House , Prinsted Lane , Prinsted Southbourne, West Sussex, PO10 8HS — Chichester District Council — Appeal Decision There is also a lack of information about what would happen to the retained foul water connection to mains drainage at Thornham STW; how flexible couplings could be provided to a buoyant structure inserted into the stationary retained walls; and how the safety of such couplings could be ensured during and after a flood event. The proposal does not show whether/where/how the drift net would be stored; how maintenance in good working order of the net and the weep holes allowing water beneath the structure could be ensured; measures to ensure the welded seams would not deteriorate and how any necessary repairs could be effected; or the effect of flood water on the retained external timber walls or concrete slab and foundations. 28. I am mindful of the PPG which acknowledges that hydrostatic pressures exerted by floodwater can cause long-term structural damage, undermine the foundations of a building or cause leakage through the walls, floor or sub-floor, unless the building is specifically designed to withstand such stresses. The PPG also advises that Flood resistance and resilience measures cannot be used to justify development in inappropriate locations1. 29.

Stables North Of Thornham Farm House , Prinsted Lane , Prinsted Southbourne, West Sussex, PO10 8HS — Chichester District Council — Appeal Decision For these reasons I am not satisfied by all the details of the scheme and I cannot confidently conclude that adequate provision would be made for the safety of future occupiers of the building in the event of flooding. Accordingly, the proposal would conflict with Policy 42 of the LP and those principles of the Framework that seek to minimise the risks of flooding and safely manage residual risks. 1 Flood risk and coastal change - GOV.UK https://www.gov.uk/planning-inspectorate 5

Stables North Of Thornham Farm House , Prinsted Lane , Prinsted Southbourne, West Sussex, PO10 8HS — Chichester District Council — Appeal Decision For these reasons I am not satisfied by all the details of the scheme and I cannot confidently conclude that adequate provision would be made for the safety of future occupiers of the building in the event of flooding. Accordingly, the proposal would conflict with Policy 42 of the LP and those principles of the Framework that seek to minimise the risks of flooding and safely manage residual risks. 1 Flood risk and coastal change - GOV.UK https://www.gov.uk/planning-inspectorate 5

Stables North Of Thornham Farm House , Prinsted Lane , Prinsted Southbourne, West Sussex, PO10 8HS — Chichester District Council — Appeal Decision Appeal Decision APP/L3815/W/25/3358934 Character and appearance 30. The special qualities of the CHNL include the unique blend of land and sea; the flatness of the landform, the sense of wildness, the picturesque harbourside settlements, the unspoilt character and unobtrusive beauty and the sense of peace and tranquillity. The Framework emphasises that great weight should be given to conserving and enhancing landscape and scenic beauty in the CHNL. 31. The site is previously developed land and the re-use of the buildings would help to ensure against future deterioration. It is fairly well screened in most views by trees and hedges. Existing openings would be re-used with relatively few new openings. Three new areas of glazing would appear in the north elevation of the longer wing, these would not be visible from the Harbour and all glazed areas would be fitted with timber shutters. The conservation rooflight that would be inserted in the north elevation would be fitted with a blackout blind. An appropriate condition could limit light spill from the rooflight to preserve the dark skies. 32. The silhouette would increase during flood events as the building floats upwards.

Stables North Of Thornham Farm House , Prinsted Lane , Prinsted Southbourne, West Sussex, PO10 8HS — Chichester District Council — Appeal Decision However, the effect of this on the appearance of the area would be relatively small. Notwithstanding the existing gates, the proposed gates and bin store on the edge of Prinsted Lane would have a suburban appearance which would not harmonise with the countryside character of the area. Although there are similar structures at the entrance to the adjacent Thornton House, I consider that introducing additional structures of this type would not respect the character of the surrounding rural landscape and would incrementally add to the gradual urbanisation of the countryside, which is identified as a significant threat to the CHNL in the Management Plan. So would additional domestic paraphernalia and car parking , although the harm would be relatively small as it would replace paraphernalia and parking associated with stable uses. 33. For the above reasons I conclude that the proposal would have a harmful, although locally limited, effect on the countryside and the CHNL and would therefore not further the statutory purposes of the CHNL.

Stables North Of Thornham Farm House , Prinsted Lane , Prinsted Southbourne, West Sussex, PO10 8HS — Chichester District Council — Appeal Decision There would be conflict with the Policies 33, 43, 45 and 48 of the LP; Policy SB4 of the NP; Policy 3 and Principle PP06 of the Management Plan; and Chapter 15 of the Framework in this respect. Other Matters 34. The appeal site is within the 5.6km Zone of Influence for the Chichester and Langstone Harbours Special Protection Area (the SPA). The UU provides for access mitigation measures in respect of recreational impacts upon the SPA. The appellant states that the necessary credits towards nitrate mitigation at Droke Lane. East Dean have been secured. 35. The A27 Chichester Bypass Mitigation Supplementary Planning Document 2024 seeks to address in-combination effects of residential development on the safety and function of the strategic and local highway network. The UU makes provision for a contribution to mitigate the effects on the highway network. 36. Given my conclusions above there is no need for me to consider these matters further as they would not change the outcome of the appeal. However, I note that taking account of the UU the Council no longer defends the reasons for refusal in relation to the effects on the SPA or the highway network. https://www.gov.uk/planning-inspectorate 6

Stables North Of Thornham Farm House , Prinsted Lane , Prinsted Southbourne, West Sussex, PO10 8HS — Chichester District Council — Appeal Decision Appeal Decision APP/L3815/W/25/3358934 37. Whilst not a determinative matter I note that the pre-fabricated sections of the proposed barge would be delivered by low loader. Prinsted Lane is narrow and curving and, had the proposal been otherwise acceptable, I would have sought more information about the practicalities of this. 38. The appellant has referred to the Thames House example of a residential development based on a floating structure. However, that was for a new dwelling constructed as a replacement for an existing dwelling so there was no new residential use created. Accordingly, that scheme included amelioration of an existing flood risk rather than an additional flood risk being created. 39. There have been extensive discussions with the Council, including before the application was submitted, and the proposal has been amended a number of times. Third Parties have raised concerns about inconsistencies between the plans. I would have sought clarification had my conclusions on the main issues been otherwise. Planning Balance and Conclusion 40. I understand that the Council considers it can demonstrate some 4.13 years supply of deliverable housing land, although this may be lower at some 3.98 years2.

Stables North Of Thornham Farm House , Prinsted Lane , Prinsted Southbourne, West Sussex, PO10 8HS — Chichester District Council — Appeal Decision The spatial strategy has been unable to deliver the requisite housing land. In the absence of a five year supply Paragraph 11(d) of the Framework indicates that planning permission should be granted unless the applications of policies in the Framework that protect assets of particular importance provides a strong reason for refusing the development proposed. Footnote 7 states this, amongst other things, includes areas at risk of flooding. In this instance the risk of flooding provides a strong reason for refusing the development proposed. Therefore, the proposal would does not benefit from the presumption in favour of sustainable development, under Paragraph 11d of the Framework. 41. The proposal would make efficient use of land and add a much needed dwelling to the local supply of housing. There would be economic benefits during the period of construction and from spend in the local economy. These benefits would be limited by the small scale of the proposal. Use would be made of an existing building and previously developed land.

Stables North Of Thornham Farm House , Prinsted Lane , Prinsted Southbourne, West Sussex, PO10 8HS — Chichester District Council — Appeal Decision However, the scheme would result in the addition of only a single dwelling to the stock, and even in a Council area without a Framework supply of housing land I consider the combined benefits should merit relatively limited weight. 42. I have found that the proposal conflicts with the spatial strategy but I give this limited weight as the strategy is out-of-date in terms of delivering the requisite housing supply. There would be some locally limited harm to the character and appearance of the countryside, albeit that such harm would result in the scheme not furthering the purpose of conserving and enhancing the natural beauty of the National CHNL. These matters together carry substantial weight. Furthermore, the proposal would not make adequate provision the safety of future occupiers of the building in the event of flooding which carries significant weight. The proposal would conflict with the Management Plan and so would not further the purposes of the CHNP. These objections together carry substantial weight and would not be outweighed by the benefits of the proposal. Indeed, the identified harm that would 2 As found in appeal Decision APP/L3815/W/24/3344538 Crouchlands Farm https://www.gov.uk/planning-inspectorate 7

Stables North Of Thornham Farm House , Prinsted Lane , Prinsted Southbourne, West Sussex, PO10 8HS — Chichester District Council — Appeal Decision Appeal Decision APP/L3815/W/25/3358934 arise, and the associated policy conflicts, would be such that the scheme would conflict with the development plan when considered as a whole. 43. In conclusion, the scheme would conflict with the development plan and material considerations do not indicate that a decision should be made other than in accordance with the development plan. Consequently, the appeal should be dismissed.

Stables North Of Thornham Farm House , Prinsted Lane , Prinsted Southbourne, West Sussex, PO10 8HS — Chichester District Council — S Harley INSPECTOR https://www.gov.uk/planning-inspectorate 8