Two storey side/rear extension, single storey front and rear extension

Appeal Decision Site visit made on 17 August 2022 by R Jones BA(Hons) DipTP MRTPI an Inspector appointed by the Secretary of State Decision date: 9th September 2022 Appeal Ref: APP/N1920/D/22/3296617 15 Heath Road, Potters Bar EN6 1LJ • The appeal is made under section 78 of the Town and Country Planning Act 1990 against a refusal to grant planning permission. • The appeal is made by Mrs Sophie Yershon against the decision of Hertsmere Borough Council. • The application Ref 21/2394/HSE, dated 15 December 2021, was refused by notice dated 15 February 2022. • The development proposed is two storey side/rear extension, single storey front and rear extension. Decision 1. The appeal is dismissed. Main Issues 2. The main issues are the effect of the proposed development on: i) the character and appearance of the host dwelling and streetscene; and ii) the living conditions of the neighbours at No.17 Heath Road, with regard outlook and light. Reasons Character and appearance 3. No.15 Heath Road (No.15) is a two-storey detached dwelling located on the western side of Heath Road in a prominent position at its junction with Westwood Close. On its Heath Road frontage, No.15 has a traditional pitched roof and projecting gable, with dormer window on the southern roofslope, and a recessed porch. To the side, between No.15 and its neighbour at No.17 Heath Road (No.17) is a single storey detached garage with facing gable, set on the same building line as the dwelling. 4. It is proposed to demolish this garage and construct a two-storey side and rear extension. The pitched roof of the host dwelling would be continued and the extension would have a projecting gable, set down from the main ridge by around 900m and the same height as the existing gable. The gable would be around 4.9m in width, so narrower than the existing, and has been set back 1m from the front building line. The variation in width and reasonable set back would break up the front elevation, reducing the overall massing, and means the proposed gable extension (in isolation) would appear a subservient addition to No.15. Appeal Decision APP/N1920/W/22/3296617 2 5. However, a large dormer window is also proposed to the southern elevation of the roofslope of the new gable. The guidance in the Planning and Design Guide Part E: Guidelines for Residential Extensions and Alterations (2006) (PDG) is that dormers should be as small as possible and should generally be located within the rear roofslope. As a general rule, the Council will resist dormers that take up more than 60% of the roof face. The proposed dormer would exceed 60% of the roof face, therein conflicting with the PDG guidance and, because of its position on the southern roofslope, the cheek of the dormer would face Heath Drive. The combination of its height, depth and position means it would be unduly prominent in the streetscene and would increase the mass and bulk of the proposed gable. 6. It is further proposed to replace the existing modest and well proportioned dormer on the southern roofslope of the existing gable with a dormer to match the new gable dormer. Individually, and together, these dormers would appear excessive in scale and would be both a dominant and incongruous addition to the host gables and the front elevation of No.15. Further, whilst I recognise that a dormer is already a characteristic of No.15 and there are other examples of dormer windows on the front roofslopes of dwellings fronting Heath Road, these are modest in proportion relative to their host roofslope. The proposed dormers would therefore fail to reflect the established character and appearance of the wider streetscene. 7. A single storey extension is proposed to the front elevation of No.15 sited between the existing porch and the southern elevation to Westwood Close. The extension has been designed with a flat lantern roof with a height of around 2.8m, just below the eaves of the adjacent gable. It would have almost full height windows to Heath Road, but would present a narrow, blank elevation to Westwood Close aligned with the existing gable. To the south side of the Westwood Close (flank) gable, a second single storey flat lantern roof extension is proposed, lower in height than the first. Both would be finished in timber (cedar) cladding. Because of the differing proportions and heights relative to each other and the existing gable, the composition of the Westwood Close elevation of No.15 would appear ill-conceived, with no overall cohesiveness in the design of the different elements. The contrast in materials between the brick of the original gable and timber cladding of the new would further highlight the lack of cohesive design. 8. The PDG guidance is that two-storey rear extensions should be sensitively positioned and designed, and at first floor should not be greater than half the width of the main dwelling. Contrary to this guidance, to the rear, the proposed two storey extension would project more than half the width of the host dwelling. It has been designed with a double gable feature linked by a large section of flat roof and whilst these would not necessarily compete as features, they would nonetheless substantially increase the scale and massing of the rear elevation. I saw from my site visit that because of its corner location, most of the existing rear elevation of No.15 is visible from Westwood Close despite the boundary fencing to the garden. The proposed double gables would appear particularly prominent in the streetscene when approaching Heath Road from Westwood Close, overwhelming the original rear elevation of No.15. This would be to the detriment of its character and appearance. 9. I observed on site that No.15 has a consistency to the rhythm, proportions and placement of windows. The proposed changes to the windows are clearly more Appeal Decision APP/N1920/W/22/3296617 3 contemporary in design than the existing, with larger openings, including triangular feature windows, finished in a grey aluminium. They would however also have a consistency in proportions and placement and I do not therefore find that they would, in themselves, detract from the overall appearance of the host dwelling. 10. Nothwithstanding this, in conclusion on the first main issue the proposed development would cause significant harm to the character and appearance of the host dwelling and wider streetscene. Consequently, it would conflict with policies SP1 and CS22 of the Hertsmere Core Strategy (2013) (CS) and Policy SADM30 of the Site Allocations and Development Management Policies Plan (2016) (DMPP) which together require development to result in high quality design that makes a positive contribution to the built environment. It would further conflict with the design objectives of Section 12 of the National Planning Policy Framework (the Framework). Living conditions 11. No.17 Heath Road (No.17) is located directly to the north of No.15 but is around 1.2m higher because of the difference in levels. No.17 is two-storey in height with an integral flat roof garage to the side which extends around half the depth of the dwelling parallel to the boundary with No.15. I saw on my site visit that there are windows at ground and first floor on the main flank elevation of No.17 and a window on the rear elevation of the garage. It is the Council’s case that the ground floor flank window is the only window to the kitchen of No.17 and this is not contested by the appellant. 12. The proposed two-storey side and rear extension would be offset from the common boundary with No.17 by around 1.5m. It would therefore be around 1.2m further from the boundary than the existing garage and would have a similar roof pitch. It would however be much higher, with the eaves of the proposed extension broadly aligning with the height of the boundary fencing, and it would extend around 7.5m beyond the rear building line of No.17. Although the roof would pitch away from the common boundary, and notwithstanding the difference in levels, it would be visible along a long length causing significant harm to the outlook from the flank and rear windows of No.17. 13. The PDG guidance is that ‘in all cases, the first floor of a rear extension should be set comfortably within a line drawn at 45 degrees from the nearest edge of any first floor neighbouring window.’ I do not have any information before as to whether there would be a conflict with this PDG, or the BRE, guidance in respect of the light afforded to the windows on the flank and rear elevation of No.17, nor whether these windows serve habitable rooms. I acknowledge that the high existing boundary fence would already cause some overshadowing to the flank and garden of No.17, but because of the depth and 2-storey height of the proposed extension and its orientation (due south) relative to No.17, I am not satisfied that there would be no loss of light such that it would cause harm to the living conditions of the occupiers. 14. Consequently, there would be a conflict with Policy SADM30 of the DMPP because the proposed development would impact on the amenity of its neighbours in terms of outlook and light. It would further conflict with the guidance at paragraph 130 of the Framework that decisions should ensure that Appeal Decision APP/N1920/W/22/3296617 4 developments create places with a high standard of amenity for existing and future users. Conclusion 15. For the reasons give above, I conclude that the appeal should be dismissed. R Jones INSPECTOR