Addition of a third storey on a two storey terraced house

Appeal Decision Site visit made on 23 June 2026 by A Chan Markovitz BA (Hons) Decision by Tamsin Law BSc MSc MRTPI an Inspector appointed by the Secretary of State Decision date: 17 August 2026 Appeal Ref: 6007608 134 Tappesfield Road, Southwark, London SE15 3EZ • 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 1, Class AA of the Town and Country Planning (General Permitted Development) (England) Order 2015 (as amended). • The appeal is made by Mr Jonny Gibb against the decision of the Council of the London Borough of Southwark. • The application Ref is 26/AP/0036. • The development proposed is “The addition of a third storey on a two storey terraced house”. Decision 1. The appeal is dismissed. Appeal Procedure 2. The site visit was undertaken by a representative of the Inspector whose recommendation is set out below and to which the Inspector has had regard before deciding the appeal. Preliminary Matters 3. In the Appellant Questionnaire, the appellant’s name has a different spelling from all the other documents in this case. In the subject header, I have recorded the appellant’s name as it appears in the Application Form and in all subsequent documents apart from the Appellant Questionnaire. 4. Under Article 3 and Schedule 2, Part 1, Class AA of the Town and Country Planning (General Permitted Development) (England) Order 2015 as amended (the GPDO), planning permission is granted for the enlargement of a dwellinghouse by the construction of additional storeys, subject to specific limitations and conditions and a requirement that the developer applies for prior approval to the local planning authority. The Council refused the application as they considered that the proposed development would not comply with Article 3, Schedule 2, Part 1, Class AA, paragraph AA.2(3)(a)(ii) of the GPDO. 5. There is no dispute between the parties that the proposed single storey rear extension would comply with all other limitations and conditions set out in paragraphs AA.1, AA.2, AA.3 and AA.4 of Article 3, Schedule 2, Part 1, Class AA of the GPDO. From the evidence before me, I see no reason to disagree. 6. The GPDO requires that when determining an application under Class AA, the local planning authority must have regard to the National Planning Policy Framework Appeal Decision 6007608 2 (the Framework) so far as relevant to the subject matter of the prior approval, as if the application were a planning application. Main Issue 7. The main issue is whether the proposed development complies with the relevant condition in paragraph AA.2(3)(a)(ii) which regards the effect of the proposed development on the external appearance of the dwellinghouse. Reasons for the Recommendation 8. The CAB Housing Ltd judgment1 confirms that the control of external appearance, as referenced in Article 3(1), Schedule 2, Part 1, Class AA, paragraph AA.2(3)(a)(ii) of the GPDO, is not limited to the effect of the proposal on the appeal site itself, but also includes effects on the appearance of neighbouring properties and the locality. As such, in this decision I have considered the effect of the proposal on the external appearance of the host dwelling and the surrounding area. 9. The surrounding area consists of short terraces of a range of architectural styles and building heights, however each terrace generally consists of a uniform row of buildings with a consistent roofline and design. 10. The host dwelling is a two-storey, front-gabled, mid-terrace house typical of development within its terrace, which generally consists of dark brick and dark timber principal elevations, white timber or render rear elevations, and grey tiled roofs with white overhanging eaves. Houses in the terrace, including the host dwelling, have flat-roofed front door canopies and brick chimney stacks on their left roof slopes. The host dwelling contributes positively to its terrace’s uniform character and strong rhythm. 11. The proposed additional storey would be incongruous with the host dwelling’s two- storey terrace. Although set back from the principal elevation and using matching materials, the proposal would interrupt the terrace’s consistent building height and disrupt the strong rhythm of the street scene. 12. Whilst, from the rear, the proposal would only be visible in small glimpses from the public realm and would not therefore harm the setting of the Nunhead Green Conservation Area, it would be prominent in views from the front on Tappesfield Road and the side on Daniel’s Road, appearing as a discordant addition to the terrace’s homogenous roofscape. 13. The appellant has drawn my attention to a side extension that was granted planning permission within the same terrace at 140 Tappesfield Road. No 140 is an end-of-terrace house and its side extension reflects the prevailing roof forms and building heights. The appeal site is a mid-terrace house on which an upward extension would appear especially prominent, drawing attention to its discordance within the terrace. No 140’s side extension therefore has a lower visual impact on the external appearance of the original house and the terrace than the appeal scheme would, and consequently I have given it limited weight in my considerations. 14. The appellant has submitted an example of a proposal similar to the appeal scheme that has been allowed at appeal, however this property has a different 1 CAB Housing Ltd v SSLUHC & Broxbourne BC [2023] EWCA Civ 194 Appeal Decision 6007608 3 character and appearance to the appeal property. Consequently, this example is not directly comparable to this appeal and does not justify the unsympathetic design proposed. 15. For these reasons, the development would not comply with the condition in Article 3, Schedule 2, Part 1, Class AA, paragraph AA.2(3)(a)(ii) of the GPDO, and would harm the external appearance of the dwellinghouse. It would also not comply with the Framework policies in relation to this prior approval matter. Other Matters 16. The appellant has submitted that the proposal would provide additional needed accommodation, however it has not been demonstrated that the existing property does not provide suitable accommodation or that this could not be achieved through a less harmful proposal. These are not however matters I can consider in a prior approval appeal as there is no provision for any type of balancing exercise under this procedure. Conclusion and Recommendation 17. For the reasons given above and having had regard to all other matters raised, I recommend that the appeal should be dismissed. A Chan Markovitz APPEAL PLANNING OFFICER Inspector’s Decision 18. I have considered all the submitted evidence and my representative’s report and on that basis the appeal is dismissed. Tamsin Law INSPECTOR