Appeal 3304721

The appeal is allowed and planning permission is granted for the proposed construction of a set-back front mansard roof dormer extension with rear mansard dormer on top of the existing first floor outrigger at [site address] , London, [postcode] in accordance with the terms of the application, Ref. 22/00805/HH, dated 31 March 2022, subject to the following conditions:

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: drawing no. A100 Site location plan; drawing no. A105 rev A Block plan; drawing no. A305 Block plan proposed; drawing no. A150 rev A Existing plans; drawing no. A152 rev A Existing sections & elevations; drawing no. A350 rev A Proposed plans; drawing no. A352 rev A Proposed sections & elevations; drawing no. A351 Proposed roof plan; drawing no. A353 Proposed side elevations.

The development for which planning permission was sought is described on the planning application form as ‘proposed construction of a set-back front mansard roof dormer extension with rear mansard dormer on top of the existing first floor outrigger.’ In its Decision Notice the Council has described the proposal differently, as ‘Construction of a rear and side dormer extension with a mansard roof including a rooflight and a setback at front’ and this is reflected on the appeal form. However, there is no correspondence before me to show that the appellant agreed to the change of description from that set out on the planning application form. Therefore, I have considered the appeal on the basis of the original description, as ‘proposed construction of a set-back front mansard roof dormer extension with rear mansard dormer on top of the existing first floor outrigger’, which is used in the formal decision and summary information above.

I consider that the main issue in this case is the effect of the proposal on the character and appearance of No. 47, the terrace of which it forms part and the locality.

No. 47 is a mid-terrace house. In common with many of the properties in that terrace, No. 47 has a front parapet at roof level which screens the front slope and ridgeline of the pitched main roof from view from the street. However, there are a number of dwellings within the row to which a mansard roof extension, including extended side parapet walls, has been added following the grant of planning permission. Particular examples drawn to my attention include nos. 33 and 35, where the mansard roof forms have been set back behind the front parapet, limiting their visual impact.

The Council’s Altering and Extending your Home Supplementary Planning Document, 2018 (SPD) indicates that an alteration at roof level should seek to preserve the character of the original house by maintaining street facing roof slopes, ridgelines and chimneys. In addition, all parapet walls and eaves should be retained where practicable.

The proposed roof extension would include the replacement of the pitched main roof of No. 47 with a mansard/dormer extension and the addition of a mansard/dormer extension to the side slope of its two storey rear outrigger. Whilst the works would include building up the side parapet walls, they would not extend above the level of the top of the property’s chimney stack, and so would not disrupt the regular rhythm of chimneys along the terraced roofscape. The existing street facing roof slope and ridgeline would not be maintained, contrary to the SPD guidance. The Council has identified that the front and rear slopes of the mansard/dormer roof forms would be more than 70 degrees. Furthermore, the front windows of the roof extension would not align vertically with the front first floor windows of the property. However, the front face of the main mansard/dormer extension would be set well back behind the front parapet of No. 47 and, as a result, views of the roof extension from public vantage points along [address] would be limited to a small proportion of its front elevation. When seen from the street, it would have a subservient appearance relative to the main front wall of the property. In my judgement, it would be unobtrusive. Furthermore, the key characteristics of the street facing elevation of No. 47, in this case the main front wall topped by a parapet and the chimney, would be preserved, consistent with the aims of the SPD. I consider that the street facing character and appearance of No. [address] of which it forms part would not be altered to any significant extent by the proposal.

Whilst the rear elements of the proposed roof extension would be set back from the eaves of the existing roof, when seen from the back the proposed roof extensions would add significantly to the bulk of the dwelling. However, in my view, it would not appear incongruous, as a number of other properties in the same terraced row have rear roof extensions that are similar in terms of bulk, including an adjoining dwelling, No. 49. The rear elevation of No. 47 already contains a variety of glazed openings, in terms of both scale and design. In that context, although the proposed new windows at roof level would add to that variety, they would not appear inconsistent or discordant, to my mind. Furthermore, it appears to me that while visible from some neighbouring properties, the back of the proposed development would be unlikely to be clearly visible from any public vantage points. In my judgement therefore, its impact on the character and appearance of No. [address] as appreciated from the rear would not weigh materially against the scheme.

The existing roofscape of the terrace of which No. 47 forms part includes a variety of roofing materials, both in terms of type and colour. There is also variation in the colour of the facing brickwork at No. [address]. In this context, the proposed pre-aged bronze standing seam material which would be used to clad the external surfaces of the proposed roof extension would not appear incongruous. In my view, it would have a high quality appearance and would compliment the colour palette of the existing brickwork.

I conclude that the effect of the proposal on the character and appearance of No. 47, the terrace of which it forms part and the locality would be acceptable. In terms of securing high quality design and positively responding to local distinctiveness, the proposal would accord with the aims of Policies D1, D3, D4 and D8 of The London Plan 2021 as well as Policies SP1, SP3 and SP8 of the Newham Local Plan, 2018 (NLP) and the National Planning Policy Framework. Under the circumstances, I consider that the identified technical conflicts with aspects of the SPD guidance would not be sufficient to justify withholding planning permission in this case.

In my judgement, due to the setbacks of the rear elements of the proposed roof extension from the eaves of the dwelling, they would be unlikely to have a significant effect on the outlook or light enjoyed by neighbouring residents. Whilst the rear windows of the proposed roof extension would allow overlooking of parts of neighbouring rear gardens, it is likely that those areas can already be overlooked from No. 47’s existing rear facing windows. I consider that the proposed addition of two rear facing windows at roof level would not add to the potential for overlooking of neighbouring dwellings to any significant extent. The effect of the appeal scheme on the living conditions of neighbouring residents would be acceptable and it would not conflict with the aims of the Development Plan as regards neighbourly development.

The Council has suggested 3 conditions which it considers should be imposed in the event that the appeal is allowed and planning permission granted. In addition to the normal commencement condition, I agree that a condition would be necessary to identify the approved plans, in the interests of certainty for everyone. A separate condition requiring that the external materials of the proposed extension match those of the existing building would not be necessary. I consider that the proposed materials, which differ to some extent from the existing, would be acceptable. They are identified on the approved plans, adherence to which would be secured by the second condition.

For the reasons given above, I conclude that the appeal should be allowed.