Two storey and single rear extension including two rear facing dormer windows to facilitate loft conversion, two front and one side elevation Velux windows and raised rear elevation terrace area with front elevation storm porch including solar panel installation on the south elevation roof plane

Appeal Decision Site visit made on 21 July 2025 by K E Down MA(Oxon) MSc MRTPI an Inspector appointed by the Secretary of State Decision date:04 August 2025 Appeal Ref: APP/P1940/D/25/3368602 35 Copthorne Road, Croxley Green, Rickmansworth, WD3 4AB • 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 & Mrs Ben Ward against the decision of Three Rivers District Council. • The application Ref is 25/0462/FUL. • The development proposed is a two storey and single rear extension including two rear facing dormer windows to facilitate loft conversion, two front and one side elevation Velux windows and raised rear elevation terrace area with front elevation storm porch including solar panel installation on the south elevation roof plane. Decision 1. The appeal is allowed and planning permission is granted for a two storey and single rear extension including two rear facing dormer windows to facilitate loft conversion, two front and one side elevation Velux windows and raised rear elevation terrace area with front elevation storm porch including solar panel installation on the south elevation roof plane at 35 Copthorne Road, Croxley Green, Rickmansworth, WD3 4AB in accordance with the terms of the application, Ref 25/0462/FUL, subject to the following 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 plans: 2024/1689/1 REV 2, 2024/1689/2, 2024/1689/3, 2024/1689/4 REV 2, 2024/1689/5 REV 2. 3) The materials to be used in the construction of the external surfaces of the development hereby permitted shall match those in the existing building. 4) The extension hereby permitted shall not be occupied until the windows in the first floor flank elevations have been fitted with obscured glazing, and no part of those windows that is less than 1.7 metres above the floor of the room in which it is installed shall be capable of being opened. Once installed the obscured glazing shall be retained thereafter. 5) The extension hereby permitted shall not be occupied until details of the privacy screens on either side of the raised patio have been submitted to and approved in writing by the Council and, following approval, have been installed in accordance with the approved details. Once installed, the privacy screens shall be retained thereafter. Appeal Decision APP/P1940/D/25/3368602 2 6) The roof area of the extension hereby permitted shall not be used for sitting out or as a balcony, roof garden or similar amenity area. Main Issues 2. There are two main issues. Firstly, the effect of the proposed first floor rear extension and roof extension on the character and appearance of the host dwelling and the surrounding area, including the street scene of Copthorne Road; and secondly, the effect of the development on the living conditions of neighbouring occupiers with respect to overlooking, privacy and light. Reasons 3. The appeal dwelling is a large, traditional two storey detached house on a very large plot, set in a row of dwellings of various sizes and designs. The house is relatively wide but shallow, has a hipped tiled roof and is constructed in dark red brick. It has a flat roofed two storey extension behind part of the original rear elevation and a detached single garage set back from the dwelling. 4. The appeal dwelling sits forward of its southern neighbour, No 33 and shares a similar building line with No 37. Copthorne Road is built on a hill with the northern end at a higher level. It also slopes from east to west with dwellings on the western side, including the appeal dwelling, being at a lower level than the street. The gardens slope away from these dwellings to the rear. 5. The proposed development involves the demolition of the two storey rear extension to which no objection is raised. I agree this would be acceptable since it is an unsympathetic addition which is partly visible in the street scene, detracting from the character and appearance of the house. 6. The existing rear extension would be replaced by a two storey rear extension some 3.5m deep and spanning the full width of the original dwelling. Beyond this, a single storey extension with a pitched, hipped roof would project to be level with the rear elevation of the existing garage. It would be marginally wider than the dwelling and would incorporate a new garage roof. A raised patio would project beyond the rear extensions. The roof of the dwelling would be re-modelled to provide second floor accommodation. The same overall height and hipped appearance would be retained but it would incorporate a modest crown. There would be two small dormer windows to the rear elevation. 7. The Council does not object to the single storey rear extension, the front porch, alterations to the existing garage, proposed roof lights and rear dormers or the proposed solar panels and I agree they would all be acceptable. I shall therefore restrict my further consideration to the two storey and roof extensions and the proposed raised rear patio. 8. The proposed two storey rear extension would be visible in the street scene, particularly when viewed from the south. From this direction it would be seen across the frontage of No 33 and would noticeably deepen the appeal dwelling. However, the increase in depth would be proportionate to the original dwelling and although readily visible it would not be out of character since, owing to the variable building line, there are other dwellings with deep side elevations visible in the street nearby. Appeal Decision APP/P1940/D/25/3368602 3 9. In order to maintain the existing eaves and ridge height and the same roof pitch, all of which would contribute to preserving the traditional character of the dwelling, a small crown roof would be incorporated. This would not be readily discernible from ground level and its modest size would ensure the roof did not appear incongruous in the context of either the host dwelling or others nearby. Therefore, although the Council’s Design Criteria set out in Appendix 2 of the Development Management Policies Document (DMP), 2013, discourages crown roofs, in this case where the resultant bulk and massing would not be out of keeping with the host dwelling, and the general perception would be of a traditional pitched hipped roof, there would be no material detriment to the character or appearance of the dwelling or the immediate area. In consequence, there would be no conflict with the policy objectives and I find the proposed roof form acceptable. 10. It is concluded on the first main issue that the proposed first floor rear extension and roof extension would have no materially harmful effect on the character and appearance of the host dwelling or the surrounding area, including the street scene of Copthorne Road. In consequence, they would comply with Policy CP12 of the Core Strategy (CS), 2011, Policy DM1 of the DMP and Policies CA2 and CA3 of the Croxley Green Neighbourhood Plan, 2018. Taken together and amongst other things, these expect development to have regard to the local context such that it is in harmony with and conserves or enhances the character, amenities and quality of the area. Specifically, extensions should respect the existing character of the dwelling through careful control of massing, alignment and height and particularly in terms of roof form, fenestration and materials and should not be excessively prominent. 11. Turning to the effect on living conditions, a patio would extend beyond the single storey rear extension. This would be some 2m from the boundary with No 37 and a greater distance from No 33. Owing to the garden sloping away from the dwelling, the patio would be built noticeably above original ground levels. In view of its elevation the Council considers that the patio could give rise to overlooking of neighbouring gardens and a consequent loss of privacy. 12. At present, vegetation would be likely to obscure significant views but since this could be removed, I agree with the Council that in order to maintain privacy between the host dwelling and its neighbours a privacy screen on either side of the patio would be necessary. I agree with the Council that such a screen should be put in place before the proposed patio is brought into use. This, together with the details of the proposed screen, could be secured through a planning condition which would overcome the potential harm. I shall impose a suitable condition. I will adjust the wording suggested by the Council because I consider it important that the details, including height and materials, are agreed in order to ensure a satisfactory appearance and functionality to protect the character and appearance of the area and the privacy of neighbouring occupiers. 13. Neighbouring occupiers have drawn to my attention that plans ref. 2024/1689/5/ Rev 2 and 2024/1689/1 Rev 2 appear to show sliding doors in the master bedroom giving access to an area of flat roof set in the otherwise pitched roof of the proposed single storey rear extension. They suggest, and I agree, that if this flat roof was used as a roof terrace or for sitting out it would be likely to lead to material overlooking and a loss of privacy at the neighbouring properties. The flat roof is not identified as a terrace on the submitted plans. Nevertheless, in order to ensure that Appeal Decision APP/P1940/D/25/3368602 4 privacy for neighbouring occupiers is secured I consider that a planning condition restricting the use of the flat roof should be imposed. The appellants have agreed to a suitably worded condition. 14. Although neighbouring occupiers have raised concerns regarding potential loss of light, I agree with the Council that, owing to the distance of separation between the buildings, no material loss of light would occur. 15. It is concluded on the second main issue that, subject to suitably worded conditions, the proposed development would have no materially harmful effect on the living conditions of neighbouring occupiers with respect to overlooking and privacy. Neither would it result in a material loss of light. In consequence, it would comply with CS Policies CP1 and CP12 and Policy DM1 and Appendix 2 of the DMP. Taken together and amongst other things, these expect new development to avoid the loss of residential amenity and in particular, maintain acceptable standards of privacy for both new and existing residential buildings. 16. Turning to conditions, I agree with the Council that, in addition to the statutory commencement condition, it is necessary to ensure that the development is carried out in accordance with the approved plans and in materials to match the existing dwelling. This is to protect the character and appearance of the host dwelling and the surrounding area. In addition, it is necessary to secure the use of obscure glazing in the first floor flank windows, which serve bathrooms. As reasoned above, a condition requiring details of privacy screens on the raised patio, their erection and retention is also necessary together with a condition restricting the use of the flat roof section of the single storey rear extension. These are all necessary in order to protect the privacy of neighbours. 17. I do not agree that a condition removing permitted development rights for additional flank windows or other openings is necessary because the standard conditions imposed would be sufficient to protect the residential amenities of neighbouring occupiers. Moreover, a condition requiring the submission of details of materials for the extensions is not necessary because, as set out above, a condition would require these to match the existing dwelling, as proposed. 18. For the reasons set out above, and having regard to all other matters raised, I conclude that the appeal should be allowed. K E Down INSPECTOR