Convert and extend existing incidental outbuilding to annexe ancillary to Dundarroch, with associated works

Appeal Decision Site visit made on 6 January 2026 by Sylvia Leonard BA (Hons) BTP MRTPI an Inspector appointed by the Secretary of State Decision date: 20 January 2026 Appeal Ref: 6002065 Dundarroch, Wildham Lane, Stoughton, West Sussex PO18 9JL • 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 Eadie against the decision of South Downs National Park Authority. • The application Ref is SDNP/25/02900/HOUS. • The development proposed is convert and extend existing incidental outbuilding to annexe ancillary to Dundarroch, with associated works. Decision 1. The appeal is allowed and permission is granted to convert and extend existing incidental outbuilding to annexe ancillary to Dundarroch with associated works, at Dundarroch, Wildham Lane, Stoughton, West Sussex PO18 9JL, in accordance with the terms of the planning application Ref SDNP/25/02900/HOUS and the plans submitted with it, subject to the attached schedule of conditions. Main Issue 2. The main issue is the effect of the proposal on the landscape character and appearance of the area. Reasons 3. The appeal site lies within open countryside to the southwest of the village of Stoughton and within the South Downs National Park (the SDNP). It is occupied by a large detached two-storey dwelling which is set well back from the public highway and accessed via a private track leading off Wildham Lane. The building is set within spacious and maturely landscaped grounds and is screened in wider views by mature trees within the site. 4. There are several outbuildings within the grounds of the property, including the building the subject of this appeal. This comprises a single storey pitched roof timber structure which is currently used for the storage of gardening equipment and is positioned to the northwest of the main house on rising garden land. 5. The proposal would provide annexe accommodation for an elderly relative comprising a large living room with study, 2 bedrooms and a bathroom. It would be facilitated through the conversion of the existing building including the introduction of new doors, windows and roof lights, together with a small lean-to single storey addition to the west elevation. 6. Policy SD25 of the South Downs Local Plan (2019) (the Local Plan) allows a limited range of development outside the designated settlement boundary. These Appeal Decision 6002065 2 exceptions include development which complies with relevant Local Plan policies and in this respect, Local Plan Policy SD25 is pertinent in that it permits annexes and outbuildings outside the designated settlement boundaries subject to a number of criteria, including a need to respect the established character of the local area and for annexes to demonstrate a functional and physical dependency on the host dwelling. 7. The Local Plan supporting guidance in applying Policy SD31 states that an annexe should usually be incorporated within, or be physically attached to, the host dwelling, and that, where an extension to provide an annexe is not practical, consideration will also be given to the size of the detached annexe and its subordinance to the host dwelling. 8. In this instance, the proposal would reuse an existing domestic ancillary outbuilding, which is positioned close to the main dwelling and other existing outbuildings to the northwest of the house. Access to the main house from the building would continue to be conveniently achieved via a garden path linking the two buildings. 9. Moreover, it is the appellant’s intention that the proposed accommodation would be contained within the same planning unit as, and maintain a functional link with, the main dwelling. This would include future occupiers using the main house for their meals and laundry related activities and sharing the same postal arrangements as the host property. 10. The building would remain within the same ownership as the main house and would share its utility services. The existing access drive, on-site parking and private garden areas would remain unaltered and would be shared by the future occupants of the annexe. 11. Taken together, the evidence suggests very strongly that, as a matter of fact and degree, what is proposed, on the balance of probabilities would comprise subsidiary accommodation to the main dwelling. Accordingly, I am satisfied that a planning condition requiring ancillary occupation of the annexe would be effective and enforceable in this case. 12. Also of significance to the determination of this appeal is that the principle of converting the outbuilding the subject of the appeal into an annexe ancillary to the host property has already been accepted by virtue of an extant permission1 (the extant permission). 13. There is no cogent evidence before me to suggest that, should this appeal be dismissed, the extant approval scheme would not be carried out. As such, I find that the extant permission has a real prospect of taking place in the alternative and that it therefore comprises a fallback position which is an important material consideration that carries significant weight for the purpose of my decision. 14. The appeal scheme differs from the extant permission by virtue of the proposed addition of a single storey extension to provide additional floor space for the living room and the conversion of part of the roof space to provide an additional bedroom, which would be served by an additional rooflight and first floor window. 1 LPA Ref SDNP/24/01378/HOUS Appeal Decision 6002065 3 15. Whilst larger than the extant permission scheme, the proposed modest increase in floorspace at ground floor level and the proposed incorporation of the additional bedroom within the existing roof space would mean that the appeal proposal would still result in a single storey height structure that would remain subservient in scale and size to the main dwelling. 16. Moreover, I am not persuaded, based on the evidence before me, that because of the proposed increased floorspace, the proposed use of the outbuilding would differ so significantly from that of the extant permission that it could reasonably be no longer considered to be functionally dependent upon the host property. The incorporation of an additional bedroom would reasonably be appropriate for family- care domestic annexes in the circumstances where long-term family care is needed and/or overnight supervision by a relative or carer is required. 17. Nor am I persuaded that the appeal scheme would significantly increase the extent of associated domestic activity so that it would be materially more harmful to the prevailing landscape character and appearance than that which would result from the extant permission. 18. The appeal scheme would utilise the same materials as those approved under the extant permission, including timber boarding clad walls and natural slate roof. Light spill from the proposed additional rooflight can be conditioned to be reduced through the fitting of blackout blinds in accordance with the extant permission. 19. Having regard to the above factors, I find that because of its combined design, scale mass and siting, the appeal scheme would sit comfortably within the appeal site without appearing visually dominant or a discordant feature within the site. it would be sympathetic to its immediate surroundings and would conserve the landscape character of this part of the SDNP countryside. 20. For the above reasons, I therefore conclude that the proposal would not materially harm the landscape character and appearance of the area. As such, it accords with Local Plan policies SD1, SD25 and SD31 in so much as these policies, cumulatively and amongst other things, seek to ensure that new development respects the established character of the local area and conserves the landscape and natural beauty of the National Park, and that annexes demonstrate the functional and physical dependency on the host dwelling. 21. For similar reasons, the appeal scheme is also contrary to policies of the Framework which seek to achieve well-designed places and conserve and enhance the natural environment as set out in Chapters 12 and 15. Conditions 22. The main parties have not suggested conditions in the event the appeal is allowed. Given that the proposal is a revised scheme to the extant permission, I have used the conditions attached to that approval as a starting point, noting that neither party has drawn my attention to any requirement to change these conditions. 23. I have considered these conditions in the light of the tests set out in paragraph 57 of the Framework and the National Planning Practice Guidance (PPG) and imposed them where I consider them to be necessary and reasonable. Where necessary, I have altered them in the interests of clarity and precision. Appeal Decision 6002065 4 24. In addition to the standard implementation condition (1), it is necessary to define the plans for certainty (2). Having regard to national and local planning policies in respect of new dwellings in the countryside and to comply with Local Plan Policy SD31, a condition is necessary to ensure that the approved annexe is occupied for purposes ancillary to the host dwelling (3). 25. In the interests of protecting the dark night skies of the SDNP, a condition is necessary to control light emission from the approved roof lights (4). Conditions are necessary in the interests of protecting wildlife, in particular bats and birds (5) and (6). 26. Conditions are necessary to ensure that the development is Nitrate Neutral in accordance with advice from Natural England to avoid adverse effects upon the integrity of the Solent Maritime SAC designated sites (7) and (8). Conclusion 27. The development accords with the development plan taken as a whole and there are no material considerations, including the Framework, that indicate that the decision should be made other than in accordance with the development plan. 28. For the above reasons, I conclude that the appeal should succeed, and planning permission be granted subject to conditions. S Leonard INSPECTOR Schedule of conditions 1) The development hereby permitted shall begin not later than three years from the date of this decision. 2) The development hereby permitted shall be carried out in accordance with the following approved plans: Site Location Plan Ref 001, Existing Elevations and Plan Ref 002, Site Plan Showing Position of Package Treatment Plant Ref 003, Proposed Annexe Elevations and Plan Ref 2 and Proposed Site Plan Ref 4. 3) The residential annexe hereby permitted shall not be occupied at any time other than for purposes ancillary to the residential use of the dwelling known as Dundarroch. 4) The roof lights hereby permitted shall be fitted with electronically timed blackout blinds in accordance with sections 6.3 and 9 of the SDNPA’s Dark Skies Technical Advice Note (May 2021). Once fitted, the blackout blinds shall be maintained in working condition and shall remain in place in perpetuity. 5) The development hereby permitted shall be carried out in accordance with the Phase 1 Daytime Bat Assessment by Dr Jonty Denton dated 29 April 2025. Appeal Decision 6002065 5 6) The development hereby permitted shall not be occupied until a bat and bird box have been installed on the site in accordance with details which have first been submitted to and approved in writing by the local planning authority. 7) The development hereby permitted shall not commence until a scheme for the long-term maintenance and management of the package treatment plant system has been submitted to and approved in writing by the local planning authority. Upon completed construction of the package treatment plant, the approved scheme shall be strictly adhered to in perpetuity. 8) The development hereby permitted shall not first be brought into use until the mitigation measures, set out within the document titled "Nutrient neutrality assessment and mitigation strategy relating to Dundarroch " submitted on 20th March 2024 has been provided on site in complete accordance with the agreed details. The Klargester BioAir package treatment plant shall be installed to an operational manner for the purposes of adequately treating the wastewater from the development. Once installed, the treatment plant shall be retained, maintained, and managed in accordance with the scheme for the maintenance and management of the treatment plant submitted pursuant to condition 7 of this permission ***End of Conditions***