572B London Road, Isleworth, Hounslow, TW7 4EP

572B London Road, Isleworth, Hounslow, TW7 4EP — London Borough of Hounslow — Appeal Decision Site visit made on 18 February 2025 by J Davis BSc MSc MRTPI an Inspector appointed by the Secretary of State Decision date: 24 February 2025 Appeal Ref: APP/F5540/W/24/3349423 572B London Road, Isleworth, Hounslow, TW7 4EP • 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 Paolo Silenoni against the decision of the Council of the London Borough of Hounslow. • The application Ref is P/2023/3943. • The development proposed is described as ‘proposed mansard roof to front and rear of existing terrace’. Decision 1. The appeal is dismissed. Main Issues 2. The main issues are: - the effect of the proposed development on the character and appearance of the existing building and on the Spring Grove Conservation Area; and - its effect on the living conditions of existing occupiers with reference to internal space. Reasons Character and appearance 3. The site comprises a three storey end of terrace property located within Spring Grove Conservation Area (CA). 4.

572B London Road, Isleworth, Hounslow, TW7 4EP — London Borough of Hounslow — Appeal Decision The CA is described in the Spring Grove Conservation Area Appraisal (CAA) as covering an extensive area, comprising for the most part a mid to late Victorian residential estate, along with early to mid-twentieth century housing and civic developments. The CA’s special architectural and historic interest derives from an estate planned to be a grand Victorian suburb, with some of the estate planning ‘in much of its splendour’ still legible. The site is within ‘The Grove and Thornbury Road’ sub-character area. The CAA identifies the site as a neutral contributor to the CA and I concur with this view. 5. Section 72(1) of the Planning (Listed Buildings and Conservation Area) Act 1990 (the Act) requires that special attention be paid to the desirability of preserving or enhancing the character or appearance of Conservation Areas. Similar advice is https://www.gov.uk/planning-inspectorate

572B London Road, Isleworth, Hounslow, TW7 4EP — London Borough of Hounslow — Appeal Decision Appeal Decision APP/F5540/W/24/3349423 contained within the National Planning Policy Framework (2024) and Policy CC4 of the Hounslow Local Plan 2015-2013 (2015) (LP). Policies CC1 and CC2 of the LP expect proposals to respond to the context and character of the area in terms of design. 6. The appeal property is in a prominent location at the junction of London Road and Thornbury Road. It sits at the end of a terrace which is of a uniform three storey height and is characterised by a parapet along its principal elevation, with a distinctive, largely unaltered, butterfly roof form to the rear. 7. The proposal would add an additional storey in the form of a mansard roof between raised party walls. Due to a combination of its height and depth, the extension would dominate the roof of the building and would appear as a bulky addition which would be very apparent in the street scene, particularly when approaching from the south-west along London Road and from Thornbury Road to the rear. 8. The proposal would result in the removal of a small entrance cabin that is visible from Thornbury Road but due to its scale and siting, it would also detract from the butterfly roof form visible from the rear.

572B London Road, Isleworth, Hounslow, TW7 4EP — London Borough of Hounslow — Appeal Decision The proposed development would disrupt the uniformity of the roof line of the three storey terrace and would stand out as a bulky, incongruous and unsympathetic addition which would be harmful to the character and appearance of the existing property and to the architectural unity and coherence of the remainder of the terrace. In terms of its detailing, the entrance on the front elevation giving access to a terrace would look awkward and would further emphasise the discordant appearance of the roof addition. Furthermore, the proposed development would detract from the views of nearby buildings within the CA, including those within the same terrace and further along London Road, and the Milford Arms, a locally listed building, on the opposite corner of Thornbury Road. 9. Accordingly, for the above reasons, I conclude that the proposal would have a harmful effect on the character and appearance of the existing building and would fail to preserve or enhance the character or appearance of the CA. Given the relatively small scale of the proposal, the harm to the CA would be less than substantial harm.

572B London Road, Isleworth, Hounslow, TW7 4EP — London Borough of Hounslow — Appeal Decision Paragraph 215 of the Framework indicates that in such circumstances the harm should be weighed against the public benefits of the scheme. No public benefits have been put forward to weigh against this harm. 10. The proposal would fail to satisfy the requirements of the Act and the design and heritage aims of Policies CC1, CC2 and CC4 of the LP outlined above. It would also be contrary to policies D3, D4 and HC1 of The London Plan (2021) which collectively and amongst other matters, require development to enhance local context through a design-led approach and to conserve the significance of heritage assets. Living conditions 11. The Council’s concern is that the proposal would fail to comply with the Nationally Described Space Standard (2015) (NDSS) and accordingly would be contrary to Policy SC5 of the LP. However, Policy SC5 of the LP appears to relate to proposals for new housing rather than to extensions and therefore is of limited relevance to the appeal. https://www.gov.uk/planning-inspectorate 2

572B London Road, Isleworth, Hounslow, TW7 4EP — London Borough of Hounslow — Appeal Decision Appeal Decision APP/F5540/W/24/3349423 12. The proposed extension would provide an additional bedroom and en-suite. The NDSS is applicable to new dwellings however notwithstanding this, the proposed bedroom would be of generous dimensions and would significantly exceed the 11.5m internal standard for a double room set out in the NDSS. The en-suite would also improve facilities within the flat as would improved external space. Other living space within the flat would remain unaltered and whilst falling short of the overall internal space standard sought for new 3-bed dwellings, it would, as a matter of judgement, continue to provide adequate, usable internal space. 13. I therefore find that the proposal would not have a harmful effect on the living conditions of the occupiers of the flat with reference to internal space. Accordingly, there would be no conflict with Policy SC5 of the LP or the Framework which seek a high standard of amenity for existing and future users. Conclusion 14.

572B London Road, Isleworth, Hounslow, TW7 4EP — London Borough of Hounslow — Appeal Decision Whilst I have concluded that the proposed development would not have a harmful effect on the living conditions of the occupiers, I have found that it would result in harm to the character and appearance of the existing building and would fail to preserve or enhance the character or appearance of the CA. 15. For the reasons given above, and having regard to all other matters raised, I conclude that the appeal should be dismissed.

572B London Road, Isleworth, Hounslow, TW7 4EP — London Borough of Hounslow — J Davis INSPECTOR https://www.gov.uk/planning-inspectorate 3