Appeal 3313697

The appeal is allowed and planning permission is granted for the erection of side infill extension and associated alterations at [site address] , Chiswick, Hounslow, London [postcode] in accordance with the terms of the application, Ref 01176/6/P3, dated 21 July 2022, subject to the following

The development hereby permitted shall begin not later than 3 years from the date of this decision.

The development hereby permitted shall be carried out in accordance with the following approved plans: Location Plan; 336-EX-01 [name]; 336- PROP-01 [name]; and [name] information received on 18/08/2022.

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.

The main issues are: • whether the proposed development would preserve or enhance the character or appearance of the Turnham Green Conservation Area (CA); and • the effect of the development on the living conditions of the occupiers of No [address] (No 4) with particular regard to light and outlook.

The site comprises an attractive two-storey semi-detached house situated in the predominantly residential area of [address]. The property and the neighbouring dwellings have large rear outriggers and there is a narrow gap separating the appeal dwelling from the house at No 4. The host property has several existing rear extensions, including a flat roof single storey addition and a lean-to side infill extension on the outrigger. There is also a side infill extension on No 4 which does not project beyond the existing one on the appeal property.

Having regard to the Turnham Green Conservation Area Appraisal 2021 (CAA), the significance of the CA derives in part from the green’s formative role in the development of Chiswick as a whole and the high quality of the residential areas to the south and west. The CA was extended in 2019 to incorporate several more streets including [address].

The CAA indicates that [address] has houses of the same basic design developed in the early twentieth century pre-war period, comprising mainly terraces or semi-detached houses with very narrow gaps which create a strong sense of unity and a regular visual rhythm to the streetscape. At my site visit, I observed that the dwellings along this part of [address] have rear outriggers attached to ones on the adjoining dwellings which also give visual rhythm to the rear built form. The street elevation of the appeal property makes a positive contribution to the CA as it comprises one of the semi-detached houses and has retained much of its original form. The rear upper floor of the house has also maintained elements of its original form, including the prominent outrigger, and makes a positive contribution to the CA. There are a number of ground floor rear extensions that make a lesser contribution.

The proposed development would be located on the rear of the property and would not be visible from the street. Whilst it would result in the creation of a ground floor wraparound extension which is contrary to the Council’s guidelines for conservation areas, the extension would be sited between the existing side and rear additions which together extend along the full width of the house and the length and width of the outrigger on the appeal dwelling. As a result, the proposal would not further obscure the rear ground floor of the host property. Furthermore, as the development would be modestly sized, with a roof and walls aligned with the existing side extension and with a similar projection to the existing rear addition, it would be appropriate in scale to the original house. A condition would ensure that it would be finished in materials to match the existing building.

Consequently, I conclude that the development would preserve the character or appearance of the CA. It would comply with Policies CC1, CC2, CC4 and SC7 of the London Borough of Hounslow Local Plan 2015-2030 (the Local Plan). Together, these require extensions to conserve the significance of the borough’s heritage assets, sensitively respond to an area’s character, and have regard to the quality, character, materials and scale of the principal building. Additionally, it would accord with the Council’s Residential Extension Guidelines Supplementary Planning Document 2017 (SPD) where it states that the scale of single storey rear extensions should be secondary to the original house and new extensions in conservation areas should never dominate in terms of bulk, scale or design. It would also comply with the National Planning Policy Framework (the Framework) where it requires consideration to be given to the impact of a proposal on the significance of a designated heritage asset.

A Daylight and [name] has been submitted with this appeal to assess the effect of the proposed extension. It confirms that the ground floor rear windows/doors serving a lounge and study at No 4 would pass the Building Research Establishment tests for both [name] and [name]. This indicates that these rooms would remain sufficiently well lit.

Due to the position of the lounge window at No 4 on the rear of the outrigger and its distance from the proposed extension, I do not consider that the development would create a significant sense of enclosure or be harmful to the outlook of the occupiers of that room.

Nevertheless, the study door at No [address] to the mutual boundary, within an existing side infill extension which does not project as far as the existing side infill addition on the appeal site. Whilst the proposal would extend this projection further and noting the SPD guidance that such proposals should not exceed 2m high on the boundary, the extension would be set back from the mutual boundary and maintain a separation distance of 0.7m from No 4, though a third party has suggested that it should be set back by at least 1m. I have taken account of the proposed separation distance, the 3.15m eaves height of the proposal, its roof form which would slope away from the neighbouring property, its design which would continue the form of the existing side extension, and the fact that the Daylight and [name] indicates that the study would remain suitably well lit. For these reasons, the proposal would not create a significant sense of enclosure or be harmful to the outlook of the occupiers of the study at No 4.

Overall, I conclude that the development would not harm the living conditions of the occupiers of No 4 with particular regard to light and outlook. It would comply with Policies CC2 and SC7 of the Local Plan. Together, these require residential extensions to minimise harm to neighbouring residents by avoiding unacceptable loss of daylight/sunlight, outlook or by creating an unacceptable sense of enclosure. In addition, it would accord with the Council’s SPD where it states that single storey rear extensions should be designed in a manner that minimises harm to neighbouring properties. The proposal would also comply with the Framework which requires decisions to provide a high standard of amenity for existing users.

The Council’s appeal statement refers to the risk of precedent if the proposal were to be allowed. In this case, I see no reason why it would undermine the Council’s ability to exercise its judgement in relation to similar development proposals on this or other sites, especially as each case is determined on its own merits and each site will have different constraints and opportunities. Moreover, as I have found the scheme acceptable in terms of character and appearance and living conditions, it will not set a harmful precedent.

In addition to the standard time limit condition, I have imposed a condition requiring that the development is carried out in accordance with the approved plans, including the fire safety information. This is in the interest of certainty. To protect the character and appearance of the area, I have also imposed a condition requiring that the external materials used in the construction of the extension will match those of the existing building.

I have considered the condition suggested by the Council relating to construction working hours. However, I have not imposed this as it would be subject to control under other legislation.

For the reasons given, I conclude that the proposal would accord with the development plan, when read as a whole, and the Framework, and therefore the appeal is allowed.