Proposed demolition of existing conservatory and construction of two-storey rear extension

Appeal Decision Site visit made on 6 October 2025 by R C Shrimplin MA(Cantab) DipArch RIBA FRTPI FCIArb MCIL an Inspector appointed by the Secretary of State Decision date: 22 October 2025 Appeal Reference: APP/Y0435/D/25/3371696 43 Wallinger Drive, Shenley Brook End, Milton Keynes MK5 7BS • 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. and Mrs. Ganguly against the decision of Milton Keynes City Council. • The application reference is PLN/2025/1099. • The development proposed is described in the application form as “Proposed demolition of existing conservatory and construction of two-storey rear extension”. Decision 1. The appeal is allowed and planning permission is granted for the “Proposed demolition of existing conservatory and construction of two-storey rear extension”, at 43 Wallinger Drive, Shenley Brook End, Milton Keynes MK5 7BS, in accordance with the terms of the application (reference PLN/2025/1099), subject to the conditions set out in the attached Schedule of Conditions. Main issue 2. The main issue to be determined in this appeal is the effect of the proposed development on the residential amenities of neighbours (whether unacceptable harm would be caused by overbearing appearance or overshadowing). Reasons 3. The appeal site is located in one of the modern residential areas of Milton Keynes, in the western part of the City. Although the layout is in the modern part of the City, the houses are traditional in form and the meandering road layout creates a pleasant suburban environment, with an established character. 4. Number 43 Wallinger Drive is set back from the road, approximately alongside number 45 (to the south-west), although number 41 is set forward, creating interest in the streetscene. Like its neighbours, number 43 is constructed of brickwork under a pitched, tiled roof, in a traditional form. Being set back from the road, number 43 does not have a deep back garden but it is set on a tapering plot that widens at the rear, which adds to the back garden. 5. It is now proposed to build a two-storey rear extension, projecting into the back garden, following the demolition of an existing single-storey rear conservatory. 6. The ‘National Planning Policy Framework’ emphasises the aim of “achieving well designed places” in the broadest sense (notably at Section 12), while making effective use of land and encouraging economic activity. It is aimed at achieving Appeal Decision: APP/Y0435/D/25/3371696 2 good design standards generally, by adding to the overall quality of the area and being visually attractive and sympathetic to local character and history, although it is also recognised that appropriate change may include increased densities. The achievement of good design includes protecting existing residential amenities and providing good standards of accommodation in new development. 7. Policies in the Development Plan share these basic design principles, including Policies that are specifically intended to protect existing residential amenities. “Plan:MK 2016-2031” was formally adopted in March 2019 and relevant Policies stress the importance of good design (for example, at Policy D1). In particular, Policy D5 points out the need to protect residential amenities, among other things. 8. The Council’s ‘New Residential Development Design Guide Supplementary Planning Document’ (which was adopted in April 2012) also raises considerations of “Residential Amenity” and is also relevant, although it does not have the force of the statutory Development Plan. 9. In this case, the proposed two-storey extension at the rear of the existing house would project significantly into the back garden area. The extension would be sited to the north-east of the adjoining garden at number 45 and would not cause significant overshadowing of the neighbouring garden, however. 10. Moreover, the existing planting near the boundary would mitigate the impact on the neighbour to an extent, while the proposed extension would be set back from its side boundary with number 45, which is at an angle to the building. I am persuaded, on balance, that the outlook from number 43 would not be affected to an extent that would be unacceptable in planning terms and that the proposed extension would not have an unduly overbearing appearance. 11. The proposed extension would evidently encroach on the shallow back garden at number 43, although an adequate garden space would be retained due to the width of the plot. Moreover, the existing conservatory projects into the garden in any case and I am conscious that other schemes have also been approved that would have some impact on the back garden. Hence, this scheme would not have a harmful effect on the surroundings generally. 12. Evidently, the appeal site lies within an established urban area, which is “sustainable” in planning terms, and the proposed extension would be a useful addition to the accommodation at Number 43 Wallinger Drive. The contribution that the appeal scheme would make to the provision of residential accommodation in the locality, even though it would be limited, weighs in favour of the appeal. 13. In consequence, I have concluded that the project would not be in conflict with the Development Plan, in principle, and I am persuaded that the scheme before me can properly be permitted, subject to conditions. Although I have considered all the matters that have been raised in the representations, I have found nothing to cause me to alter my decision. 14. I have, however, also considered the need for conditions and, in imposing conditions, I have taken account of the conditions suggested by the Council in the usual way (without prejudice to their main arguments in the appeal). In particular, I have concluded that conditions are necessary, to define the planning permission and to ensure that quality is maintained. Appeal Decision: APP/Y0435/D/25/3371696 3 15. In their note on conditions, the Council have also included an “Informative” to draw attention to the fact that “this development has the potential to impact great crested newts, a European protected species, as there are ponds/waterbodies and suitable habitat within 500m of the development”. The Council goes on to point out that, “if great crested newts are discovered during development, all works must cease until advice has been sought from Natural England, as failure to do so could result in prosecutable offences being committed”. The advice is opportune. Nonetheless, I do not believe that an additional formal condition is necessary to impose a specific control in respect of possible wildlife implications, since this is covered by other legislation. Roger C. Shrimplin INSPECTOR Appeal Decision: APP/Y0435/D/25/3371696 4 SCHEDULE OF CONDITIONS 1) The development hereby permitted shall begin not later than 3 years from the date of this decision. 2) The development hereby permitted shall be carried out in accordance with the following approved drawings: drawing number PL01 (Existing Site Location & Proposed Block Plan); drawing number PL02 (Existing Site Photos); drawing number PL03 (Existing Plans); drawing number PL04A (Proposed Plans); drawing number PL05A (Existing & Proposed Elevations). 3) The materials to be used in the construction of the external surfaces of the development hereby permitted shall match those used in the existing building.