Retrospective planning application for part first floor rear extension

Appeal Decision Site visit made on 11 November 2025 by Kim Vo MPLAN Decision by John Morrison BA (Hons) MSc MRTPI an Inspector appointed by the Secretary of State Decision date: 11 December 2025 Appeal Ref: 6000711 28 Thornhill Avenue, Plumstead, Greenwich SE18 2HS • 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. M Asghar against the decision of Royal Borough of Greenwich. • The application Ref is 25/1092/HD. • The development proposed is described as “retrospective planning application for part first floor rear extension”. Decision 1. The appeal is allowed and planning permission is granted for the development described as “retrospective planning application for part first floor rear extension” at 28 Thornhill Avenue, Plumstead, Greenwich SE18 2HS in accordance with the terms of the application, Ref 25/1092/HD, subject to the following condition: 1) The development hereby permitted relates to the following approved plans insofar as they relate to the first floor rear extension only: drawing references PP-13490349v1; AR / 01; AR / 07; AR / 09; and AR / 11. 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 and Main Issue 3. The submitted plans show a single storey side extension and a front porch which are stated as being granted under application reference 23/2196/HD. They also show a hip to gable loft conversion and rear dormer, purported to be permitted development confirmed under a Lawful Development Certificate (reference: 18/2481/CP). The Council has indicated that these developments have not been built in accordance with what has been approved. The hipped roof front porch which I saw on site also does not match the mono-pitch roof which is shown on the submitted plans. 4. Notwithstanding this and given that the appellant has applied for the first floor rear extension only, this decision will focus thereon. Specifically, its effect on the character and appearance of the host dwelling. Reasons for the Recommendation 5. The appeal building is situated to the end of and occupies the lowest ground level of the two storey terraced row it sits within. It also comprises front, side and rear Appeal Decision 6000711 2 extensions, a pitched roof with a rear dormer, as well as a first floor rear extension which is subject to this appeal. The surrounding area is residential and predominantly comprises traditionally designed, two storey hipped and pitched roofed properties arranged in terraces or as semi-detached pairs. Many have been altered over more than one floor in some cases and major changes relate mostly to the rear elevations, where the street scene maintains some original consistency in elevational treatment and set back. 6. The first floor rear extension features a matching eaves line, with its overall height set below the main ridge, establishing it as a subordinate addition. It is also set in from the adjoining property, with a total footprint and projection that appears proportionate and in scale with the host dwelling. Given the appeal building’s siting on a lower land level, the extension does not appear as a dominating structure. Its roof design also complements with the surrounding hipped roofs, and it is finished in matching materials to the host. Moreover, the difference between the appeal scheme and the proposed plans approved under reference 23/2195/HD for the first floor rear extension are not substantial. 7. Additionally, it complies with Principle I.3.4 of the Urban Design Guide Supplementary Planning Document 2023 (SPD), which advises a width of no more than half the width of the plot. However, it does not accord with Figure i.45 which indicates a maximum width of no more than half the width of the original house. Notwithstanding this, the SPD is for guidance, and the proposal does not relate to a double storey rear extension. 8. For these reasons, the first floor rear extension does not cause harm to the character and appearance of the host dwelling. Accordingly, it does not conflict with Policy D3 of the London Plan 2021; Policies DH1 and DH(a) of the Royal Greenwich Local Plan 2014; and the National Planning Policy Framework. Together, and amongst other things, these require development proposals to be of a high quality design, where proposals for rear extensions should be limited to a scale and design appropriate to the building and locality. Other Matters 9. The Council has referred to a previous decision at the appeal site for a first floor rear extension of similar dimensions (reference 19/4209/HD), which was dismissed at appeal (reference APP/E5330/D/20/3254533). However, this appears to relate to a flat roof development and is not comparable to the appeal scheme given the revisions made to its roof design. 10. The appellant’s alleged unauthorised developments and breach of conditions are matters for the Council’s planning enforcement team and are not for me to resolve here. Any noise and disruption occurring from construction works would also be for a temporary period. The first floor rear extension is now complete. Conditions 11. To provide certainty and for enforcement purposes, it is necessary to impose a condition to specify the approved plans the development relates to. As the development has been fully constructed, a condition for a time limit and to control materials is not necessary. Particularly since the finished materials are acceptable for the dwelling. Appeal Decision 6000711 3 Conclusion and Recommendation 12. For the reasons given above, I recommend that the appeal should be allowed given it complies with the development plan and there is nothing compelling to suggest a decision other than in accordance therewith. Kim Vo APPEAL PLANNING OFFICER Inspector’s Decision 13. I have considered all the submitted evidence and my representative’s report and on that basis the appeal is allowed, and planning permission is granted, subject to the condition set out. John Morrison INSPECTOR