Two storey rear extension and extension to side porch

Appeal Decision Site visit made on 25 March 2026 by J D Clark BA (Hons) DpTRP MCD DMS MRTPI an Inspector appointed by the Secretary of State Decision date: 1 April 2026 Appeal Ref: APP/M2372/D/25/3369269 1 Derby Street, Blackburn, Blackburn with Darwen BB1 5HR • 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 Islam against the decision of Blackburn with Darwen Borough Council. • The application Ref is 10/24/1023. • The development proposed is two storey rear extension and extension to side porch. Decision 1. The appeal is dismissed insofar as it relates to the proposed two storey rear extension. The appeal is allowed insofar as it relates to the proposed side porch and planning permission is granted for a side porch at 1 Derby Street, Blackburn, Blackburn with Darwen BB1 5HR in accordance with the terms of the application, Ref 10/24/1023, insofar as relevant to that part of the development hereby permitted and subject to the following 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 drawing no PCE-Islam-may-24-planning, dated 10th May 2024 except in respect of the two storey extension. 3) The external materials of the porch hereby permitted shall match those used in the existing dwelling. Preliminary Matters 2. A consultation draft of the National Planning Policy Framework (the Framework) was published on 16 December 2025. Given that this is at the consultation stage and taking into account the matters before me, I do not consider it necessary to invite comments from the parties. 3. The Council has not raised any concerns about the proposed side porch and I also do not see any harm with it. My main issue therefore relates to the proposed rear extension only. Accordingly, I have issued a split decision as set out above and explained below. Main Issue 4. The main issue is the effect of the proposed two storey extension on the living conditions of the occupiers of No 3 Derby Street by reason of outlook and daylight. Appeal Decision APP/M2372/D/25/3369269 2 Reasons 5. The appeal site comprises a two-storey house that has previously been extended to the rear. It is located on the corner of Derby Street and Belper Street. The house is orientated so that it has elevations facing both Derby Street and Belper Street but with its rear garden adjoining the side boundary of No 3 Derby Street. The proposal would extend the house closer to the boundary with No 3. 6. No 3 Derby Street has ground and first floor windows in the side gable. The ground floor window is stated as serving a kitchen. There is an extremely small amount of space between the rear elevation of No 3 and its rear boundary fence and the kitchen appears to have no other window other than that on the side of the house. 7. The outlook from the kitchen window is already compromised by the boundary wall and fence and the proximity of the already extended No 1. Although the proposed rear extension would set the first floor in from the ground floor, the overall bulk would be noticeably closer to No 3. It would also extend across the full width of the house whereas the existing extension does not. Although the view of the proposed extension would be slightly off-set due to the position of the window, this would be insignificant as the side and rear of No 3 already appear hemmed in by boundary walls and fencing. Enlarging No 1 further would add to its bulk and massing. The existing compromised outlook is no excuse for making it worse. The proposal would appear overbearing and reduce natural light into No 3 and result in a very poor outlook for its occupiers. 8. The Council’s SPD1 Policy RES E3 provides guidance relating to the separation distances between facing windows and between windows of habitable rooms and blank gables and habitable rooms. The proposal would result in a distance considerably shorter than the 21 metres and 13.5 metres referred to in the SPD. 9. The Council has not refused the extension on it effect on the character and appearance of the area but this does not overcome the harm I have identified. Indeed, it would elongate the area of blank brickwork along the Derby Road elevation emphasising its large, bland and bulky appearance. 10. The proposed two storey extension would have a harmful effect on the living conditions of the occupiers of No 3 Derby Street by reason of outlook and daylight. As well as falling short of the standard in the SPD, this would conflict with Local Plan2 Policy DM02 which, amongst other things, seeks to secure a satisfactory level of amenity for existing occupants with regard to matters including light and the relationship between buildings. 11. As referred to in my procedural matter above, the porch is not referred to by the Council in its reason for refusal. Whilst described as a side porch it would actually be on the front elevation facing Derby Road. Although highly visible and larger than the existing porch, it would be modest in size and unobtrusive in the street scene. I find no harm with this element of the proposal. 12. Policy RES E16 of the SPD sets out criteria for porches relating to appearance, scale and the effect on the character of the street. The proposal would not conflict 1 Blackburn with Darwen Borough Council – Residential Design Guide Supplementary Planning Document Revised Edition September 2012. 2 Blackburn with Darwen Borough Council Local Plan 2021 – 2037, Adopted on the 25th January 2024. Appeal Decision APP/M2372/D/25/3369269 3 with these criteria. Also, it would not conflict with Local Plan Policy DM02 with regard to protecting the amenity of the occupiers of neighbouring properties. Furthermore, along with Policies CP8 and DM27, it would be of an acceptable design and safeguard the character of the surrounding area. 13. I consider that the two parts of the proposal are clearly severable and the porch is capable of being constructed independently of the two storey rear extension. As such, I am able to issue a split decision. Conditions 14. I have considered the conditions suggested by the Council in the light of the Framework and the Planning Practice Guidance insofar as they relate to the proposed porch only. In addition to the standard time limit, a condition requiring the proposal to be carried out in accordance with the approved plans, insofar as it relates to the porch, is necessary for the avoidance of doubt and in the interests of proper planning. Also, as the porch would be on the front of the house and very visible, it is important that it is constructed in materials which match the existing house in order to achieve a satisfactory appearance. Conclusion 15. For the reasons given above the appeal should be allowed in part and dismissed in part. J D Clark INSPECTOR