Extension of the existing basement with the addition of a front lightwell

Appeal Decision Site visit made on 17 February 2026 by Lisa Clark BA(Hons) DipTP MRTPI an Inspector appointed by the Secretary of State Decision date: 02 April 2026 Appeal Ref: 6001810 15 Abinger Road, Chiswick, Hounslow, London W4 1EY • 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 Mrs Preeti Ahlawat against the decision of the Council of the London Borough of Hounslow. • The application Ref is P/2025/2481. • The development proposed is extension of the existing basement with the addition of a front lightwell. Alteration to the front garden, including the installation of the new front fence. Decision 1. The appeal is dismissed. Preliminary Matters 2. The description above refers to the term basement; however, I am mindful that the Council, in its delegated report, uses both basement and cellar. For consistency, I have used both terms in my decision, treating them as meaning the same thing. 3. The proposal is for an extension of an existing basement with the addition of a front lightwell and alteration to the front garden to include the installation of a new front fence. The Council has indicated that it has no objections to the replacement boundary provided that it can approve details relating to materials. Based on the evidence before me, I have no reason to take a different view. The dispute between the parties relates to the extension of the existing basement and the addition of a lightwell, and these shall be the focus of my assessment. Main Issue 4. The main issue is the effect of the proposal on the character and appearance of the host property, and whether the proposed development preserves or enhances the character or appearance of Bedford Park Conservation Area (the CA). Reasons 5. The CA consists of a unified and historically important residential estate developed mainly in the late 1870s and 1880s in the “Queen Anne” style. The Bedford Park CA guidance sets out that Bedford Park is probably the best-known and best- preserved later Victorian suburb in outer London. Its special interest is characterised by the carefully composed architect-designed buildings, of which detached houses are rare, and the siting of individual houses placed close to the pavements which make a direct impact on the street scene. The significance of this part of the CA is therefore characterised by dwellings with predominantly modest front gardens. Appeal Decision 6001810 2 6. The appeal site (No 15) is a detached dwelling located on the corner of Abinger Road and Blemheim Road. I saw that the front garden is shallower than others within the immediate vicinity. This is partly due to its corner position and the orientation of the dwelling to its boundary, but also to the the presence of the bay window which projects forward of the front elevation. Its detached nature and corner-turning location result in No 15 making a positive contribution to the character and appearance of the CA. 7. The CA guidance states that in line with the original philosophy of the CA, basements were abolished and seeks to restrict future excavation due to them being alien to the character of the buildings and their front gardens. This restriction corresponds with Hounslow’s Character, Sustainability and Design Codes SPD Part A5 Residential Extensions Guidelines (the SPD). 8. The proposed development involves a substantial extension to the current cellar towards both the front and rear of the property, with the addition of a front light well and access into the newly created external space. Submitted plan1 shows the room to the front would be a gym. Whilst the majority of the extended cellar would be beneath the current dwelling, the lightwell would project approximately 0.9 metres beyond the main front elevation and extend beyond the width and depth of the existing bay window. This would result in the living accommodation of No 15 being brought closer to the pavement than it is currently. 9. I acknowledge that the appellant intends to retain the existing plants behind the current boundary. However, notwithstanding this, the appellant does not dispute the lightwell would be visible to pedestrians passing by. Even if the plants and the replacement boundary would partially screen views of the lightwell and metal grid from longer range views within the streetscape and CA, I have nothing before me to secure the retention of the planting. Furthermore, the replacement boundary would do little to screen the proposed development from views within the immediate vicinity. 10. Given the limited size of the front garden and proximity of the lightwell to the pavement, the presence of the basement would be evident particularly during the hours of darkness, when illumination of the room would likely result in upwards light spill. 11. The appellant has drawn my attention to a number of examples in Fairfax Road and Abinger Road, which they contend are similar. The Council do not dispute that planning permission has been granted for basement extensions along Fairfax Road2 between 2004 and 2016, and Abinger Road3 between 2014 and 2016. However, the Council assert that these predate the adoption of the SPD, and I have nothing in the evidence to demonstrate otherwise. 12. In the case of 35 Fairfax Road4 (No 35), the Inspector states it would appear that most, if not all, properties already have cellars as evidenced by the number of dwellings with small windows or vents beneath front windows. This supports my observations; however, as noted above, many of these were granted planning permission prior to the adoption of the SPD. Furthermore, whilst Fairfax Road is in close proximity to No 15, the two streets are viewed separately with little visual 1 A_15AR_HP1_PR_200A - PROPOSED FLOOR PLANS 2 Nos 17, 20, 24, 26, 28, 31 and 41 3 Nos 32, 66, 102 4 APP/F5540/D/23/3335665 Appeal Decision 6001810 3 connection between their front elevations and no visual connection between No 15 and the lightwells. Rather, the context of Fairfax Road and the appeal premises are significantly different from one another to be comparable. I therefore attach little weight to their presence. 13. In the case before me, the SPD is material. Paragraph 19.5 states, amongst other matters, that basements to the front elevation in CA would usually be resisted as these can be incongruous additions to the street scene which involve unacceptable loss of garden space that diverge from the style of the host property and its neighbours. It goes on to say that, in the case of the Bedford Park CA, no basements are allowed5. Consequently, a basement and a lightwell would be an incongruous addition to the street scene of the type that the SPD seeks to avoid. 14. Policies CC1, CC2 and CC4 of Hounslow Local Plan 2015-2030 Volume One (Local Plan) collectively seek to ensure that development conserves and takes opportunities to enhance the character of the area, and respect the grain, scale, form, proportions and materials of the surrounding area and existing architecture. Given my findings above, the proposal would be uncharacteristic within the immediate context. It would therefore harmfully alter the appearance of the host property and would not preserve or enhance the character and appearance of the CA. 15. Whilst I accept that the changes proposed would be localised in terms of the CA as a whole, and the harm to its significance would be less than substantial, paragraph 212 of the National Planning Policy Framework (the Framework) advises that when considering the impact of a proposed development on the significance of a designated heritage asset, great weight should be given to the asset’s conservation. This is irrespective of whether any potential harm amounts to substantial harm, total loss or less than substantial harm to its significance. Paragraph 213 further advises that any harm to, or loss of, the significance of a designated heritage asset (from its alteration or destruction, or from development within its setting) should require clear and convincing justification. Paragraph 215 requires that this harm be weighed against the public benefits of the proposal. Public Benefits 16. I acknowledge that the proposal would provide additional accommodation for the appellant. This would be a private benefit. There would also likely be a small temporary economic public benefit during construction. From the evidence before me, the benefits would therefore be largely private, and I have not been made aware of any public benefits arising from the proposal that would outweigh the harm I have identified. 17. Consequently, there would not be clear and convincing justification for harm to, or loss of significance of, the designated heritage asset as required by paragraph 213 of the Framework, nor would the great weight that should be given to the heritage asset’s conservation be outweighed. 18. In the absence of public benefit, I conclude that the proposed basement and lightwell would fail to preserve or enhance the character and appearance of the host property and the CA. Consequently, the proposed development would conflict with policies CC1, CC2, CC4 and SC7 of the Local Plan, insofar as they seek to 5 Paragraph A5.167 Appeal Decision 6001810 4 ensure proposals protect the character of the building and are harmonious with its surroundings and the wider character of the area. There would also be conflict with the guidance contained within the SPD. The proposal would also be contrary to the provisions of the Framework in relation to heritage assets. Other Matters 19. I sympathise with the appellant’s frustrations with regard to planning approvals on Fairfax Road; however, I have determined this appeal on its individual planning merits and based on the information before me. 20. The absence of harm to existing nearby occupants, with particular regard to daylight, privacy or outlook, are neutral matters in the overall planning balance, as these would be likely requirements of a well-designed development. Conclusion 21. For the reasons given above, having regard to the development plan as a whole and all other material considerations, I conclude that the appeal should be dismissed. Lisa Clark INSPECTOR