Erection of first floor side extensions to both sides, part ground floor front extension, loft conversion with front and rear dormers, roof height increase of 300mm, and associated internal alterations

Appeal Decision Site visit made on 19 August 2026 by K Reeves BA (Hons) MA MRTPI an Inspector appointed by the Secretary of State Decision date: 04 September 2026 Appeal Ref: 6008320 5 Somerset Way, Iver, Buckinghamshire SL0 9AG • 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 Navpreet Johal against the decision of Buckinghamshire Council. • The application Ref is PL/25/2749/FA. • The development proposed is erection of first floor side extensions to both sides, part ground floor front extension, loft conversion with front and rear dormers, roof height increase of 300mm, and associated internal alterations. Decision 1. The appeal is dismissed. Preliminary Matters 2. As part of the appeal, the appellant submitted a Preliminary Roost Assessment (PRA) prepared by Arbtech and dated 2 April 2026. The PRA has been provided to address the Council’s second reason for refusal and is intended to supply the ecological information that was absent at application stage. Its submission does not alter the nature or scale of the development and therefore does not constitute a substantive change to the scheme. 3. The submission of technical evidence at appeal is not unusual and is an accepted part of the process, particularly where it does not amend the development itself. The PRA provides the information intended to assess ecological impacts. I am satisfied that accepting the PRA in determining the appeal does not prejudice the interests of any party, and I have taken it into account in reaching my decision. 4. A revised National Planning Policy Framework was published on 17 August 2026. While this made certain revisions to aspects of national planning policy, the provisions in respect of the matters relied on by the main parties are materially unchanged. Therefore, no injustice would arise if I determined the appeal on the basis of the evidence already submitted. Main Issues 5. The main issues are the effect of the proposed development on: • the character and appearance of the host building and the area; and • protected species. Appeal Decision 6008320 2 Reasons Character and appearance 6. The existing dwelling at No.5 is a traditional gable-fronted building whose architectural identity remains clear despite earlier ground-floor additions. The front gable sets the hierarchy of built form and gives the house a coherent vertical emphasis. Its proportions, including the relationship between eaves and ridge height and the massing of the lower elements, remain balanced, and the historic extensions have not displaced the primacy of the original roof. 7. The proposal would significantly disrupt this composition. Replacing the main gable with a crown roof would be a clear break from the dwelling’s established form. The crown structure would introduce a broad, horizontal emphasis that visually suppresses the gable’s vertical emphasis, and the raised eaves would shift the perceived mass upward, creating a new dominant line that competes with the original roof structure. 8. Although the first-floor side extensions are set back from the boundaries, they would add substantial mass across the width of the plot and further emphasise the altered proportions created by the changes to the roof form. The retained ground-floor gabled elements would sit awkwardly beneath the new roof, with the two forms appearing to compete rather than integrate, and the fenestration changes would add to this lack of cohesion. Overall, the scheme would read as an incongruent re-composition rather than a sympathetic extension, failing to respect the established form of the dwelling. I therefore find conflict with Policy H11(a) of the South Bucks District Local Plan (1999) (LP). 9. Somerset Way contains bungalows, chalet-style dwellings, two-storey houses and more recent crown-roofed buildings, creating a varied street scene without a single prevailing form. In that context, the proposed development would not appear out of place, and its massing would sit within an environment already characterised by differing roof profiles and building scales. Boundary gaps would be retained, avoiding any terracing effect, and the height increase would not disturb the established rhythm of spacing or staggered building lines. Although visually prominent, the development would not materially harm the character and appearance of the area and would comply with Policies EP3 and H11(c) of the LP. 10. The redevelopment at No.15 shows that crown roofs are not unfamiliar within the street and that the architectural character of the area is evolving. However, that scheme involved a complete replacement building and does not lessen the requirement in Policy H11(a) for extensions to harmonise with the existing dwelling. The acceptability of that scheme does not translate to acceptability where integration with an established form is required. While No.15 demonstrates that larger, contemporary forms can be absorbed within the varied street scene, it does not overcome the appeal proposal’s failure to harmonise with the host building in terms of scale, height, form and design, nor does it provide a precedent that outweighs the identified policy conflict. 11. Having regard to the above, although I have found that the proposal would not cause material harm to the character and appearance of the area, it would result in unacceptable harm to the character and appearance of the host building. Consequently, the proposal conflicts with Policy H11(a) of the LP, and as the policy requires compliance with all applicable criteria, the failure to satisfy the Appeal Decision 6008320 3 building-specific limb means the proposal conflicts with Policy H11 when taken as a whole. Protected species 12. The PRA records that no bat evidence was found during the inspection and that the loft void contains no specific roosting features. It also identifies missing mortar and loose tiles which may provide crevice access beneath the roof covering. The report concludes that the building has low habitat value for roosting bats and recommends one emergence or re-entry survey during the active bat season to confirm presence or likely absence. 13. Circular 06/2005 establishes the legal framework within which planning authorities must operate when determining applications that may affect protected species. It states that “the presence or absence of protected species, and the extent that they may be affected by the proposed development, should be established before planning permission is granted,” and that surveys “should only be required where there is a reasonable likelihood of the species being present.” As the competent authority for the purposes of the Conservation of Habitats and Species Regulations 2017 (the Habitats Regulations), I must be satisfied that the development would not result in the disturbance or destruction of a European Protected Species or its breeding site or resting place. 14. The PRA identifies low potential but does not establish likely absence. Where the baseline survey does not confirm whether bats are present, the competent authority cannot rule anything in or out without a seasonally timed emergence survey. In such circumstances, the further survey is not precautionary, it is necessary to determine whether the development would disturb or destroy a roost. Without that survey, I cannot lawfully conclude that the proposal would not harm a European Protected Species or that any required mitigation would be proportionate and effective. 15. In these circumstances, the ecological information before me is insufficient to discharge my duties under the Habitats Regulations, and the appeal cannot be allowed unless the recommended survey has been completed and its findings are available at determination stage. The proposal therefore conflicts with Policy CP9 of the South Bucks Core Strategy (2011), which requires development to protect and enhance biodiversity and to demonstrate that adverse impacts on protected species have been robustly assessed and appropriately addressed. Other Matters 16. I recognise the appellant’s explanation that the existing first-floor arrangement is constrained by limited headroom and inefficient circulation, and that the proposal would deliver a more coherent and usable layout with improved proportions better suited to modern living. I also acknowledge the potential to upgrade the building fabric, improve insulation and enhance the overall thermal performance of the dwelling. These are benefits of the scheme. However, the appellant has not demonstrated that these improvements could only be achieved through the specific form of development proposed, nor that alternative approaches would be incapable of delivering comparable gains without generating the harm I have identified. In the absence of such justification, the benefits attract only limited weight and do not outweigh the identified harm or the resulting conflict with the development plan. Appeal Decision 6008320 4 Conclusion 17. For the reasons given above, the proposal conflicts with the development plan and the material considerations do not indicate that the appeal should be decided other than in accordance with it. Accordingly, the appeal should be dismissed. K Reeves INSPECTOR