Appeal 3320765

The appeal is dismissed.

A local resident at the application stage said that the property was being extended to create another house in multiple occupation. That is not part of the proposal before me which I must determine on its own merits. The Council has separate powers to investigate any possible breaches of planning control.

The appellant’s statement and the existing plans lead a reader to think that the appeal dwelling already benefits from a full-width rear dormer, 3 front roof lights and a large single-storey rear extension. That is not the case, although I saw that the perimeter blockwork walls for the latter extension are in place. That said, I acknowledge that a lawful development certificate (LDC) with ref. 20/0659/CLP and a prior approval determination with ref. 20/0648/PD42 are in place for a rear dormer with 3 front roof lights and a ground floor rear extension respectively. This fallback is an important material consideration and the identified discrepancies in the plans do not count against the appeal.

The Council raised no objections to the proposed ground floor front extension. I see no reason to take a different stance.

The main issue is the impact of the proposed first and second floor extensions at the rear upon the character and appearance of the host dwelling.

The appeal concerns a 2-storey, semi-detached house with a traditional pitched roof. It is typical of the housing found along this part of the eastern side of [address] where each of the pairs follow a staggered building line.

No. 140 has a good-sized back garden which rises up away from the house and takes its place within the large, rectangular-shaped block of residential gardens enclosed by the properties on [address], [address], [address], [address] and [address].

The gist of the proposal at the rear is twofold: adding a first floor rear extension across the full width of the original rear elevation to a maximum depth of about 3 m, over about half of the 6 m deep ground floor rear extension; and building a sizeable flat-roofed box dormer above that first floor rear extension, reaching back over the existing rear roof slope.

The proposal would plainly not be restrained in design terms. Except for exceedingly modest recesses from the ridge, sides and eaves, the dormer would extend over the full area of the rear roof slope. It would also reach out over the full-width first floor rear extension well beyond the original rear elevation of the house. The proposal would create the appearance of an awkward and bulky large box, the top of the roof-level flat roof covering almost the same depth as the original side gable end of the house. The property would take on a top-heavy appearance and give the impression of having a full third storey. When considered cumulatively, the siting, the flat-roof design and the sheer size of the rear additions would be a step in the wrong direction in terms of scale and proportion in comparison to the existing house and the semi-detached pair as a whole. Even though matching materials would be used, the proposed development would visually dominate the building’s rear elevation.

It would be apparent from several neighbouring gardens in the rectangular-shaped block of residential gardens I referred to in paragraph 7 that the scheme would be out of keeping with the form and scale of the host property and amount to an overly bulky addition. In turn, the excessive rearwards projection of the uppermost rear flat roof would also draw the eye from public viewpoints on [address] when passing in front of nos 136 and 138.

That the scheme eschews the guidance in the Hertsmere Planning and [name] - Guidelines for [name] and Alterations Supplementary Planning Document (SPD), adopted in November 2006, confirms my findings. The SPD explains that first floor rear extensions should not be greater than half the width of the main house. Dormers should be as small as possible and, as a general rule, the Council will resist dormers that take up more than 60% of the roof face. Measured vertically, dormers should be set at least 30 cm from the main roof ridge and eaves to remain a subservient feature of the roof. To avoid being highly visible from the street scene, a dormer should be set in from the sides by at least 50 cm. The SPD carries weight as a material consideration in decision making. Whilst it contains recommendations as opposed to planning policy, the Council had a reasonable expectation for the appeal scheme to show more consistency with the SPD.

The appellant notes several examples of full-width rear dormer extensions at this northern end of [address]. This means that the majority of houses in this part of the road remain without such a dormer type and 2 contribute significantly to the locality’s character. Apart from the planning permission (ref. 16/1976/FUL) for nos 136 and 138 next to the appeal site, I have no evidence of the Council recently granting planning permission for any of the other large flat-roofed rear dormers highlighted and therefore considering them acceptable. It is reasonable to assume that all or most of those other rear dormers came about through historic planning decisions, permitted development rights or certificates of lawfulness or are unauthorised or have become lawful through the passage of time. They do not justify the appeal scheme in the face of the harm it would cause and the SPD cautions that the presence of nearby large and unsightly dormers built through permitted development legislation will not be considered as an acceptable reason to build similarly large dormers.

It is not clear to me whether the developments that have taken place at nos 136-138 are entirely in accordance with the approved plans provided with the appeal statement. The box dormers seem to be closer to the roof ridges than the plans envisaged. More crucially, that semi-detached pair were remodelled to provide a roof with a shallower pitch and a wider gable where the dormers are sited within the confines of the new rear roofs, rather than extending beyond the rear elevations as would be the case in the appeal scheme. What is proposed at no. 140 would not be a logical progression as said by the appellant. It is the staggered siting and probably the ground levels, more so than the developments themselves at nos 136 and 138, that lead to a sense that this neighbouring building dwarfs no. 140. Similarly, the fallback of the LDC would not result in an equivalent or greater amount of harm to the character and appearance of the host dwelling when compared to the appeal scheme. Neither the developments at nos 136-138 nor the LDC would justify a grant of planning permission for the appeal scheme.

I find on the main issue that the proposed first and second floor extensions at the rear would harm the character and appearance of the host dwelling. There would be conflict with the aims of Policies SP1, SP2 and CS22 of the [name] 2013 and Policy SADM30 of the Site Allocations and Development Management Policies Plan 2016. These policies, amongst other things, seek to ensure development is of high quality design and appropriate in scale, makes a positive contribution to the built environment and is consistent with the SPD. Despite the dates of the adopted policies, I judge that they are important policies looked at in the round, remain consistent with the National Planning Policy Framework (the Framework) and are not out-of-date as such.

The Framework, in seeking to achieve well-designed places, advises that good design is a key aspect of sustainable development; so, development should add to the overall quality of the area and be visually attractive as a result of good architecture and sympathetic to local character. I consider that the appeal proposal is ill-judged in these important respects. The scheme may fulfil the social objective of sustainable development as set out in the Framework, where it provides additional habitable accommodation including home working space, and offer limited benefits under the economic objective for instance to local builders and tradespeople. On the other hand, the environmental objective would not be fostered given the harm to the built environment I have found under the main issue. 3

The Council, applying a somewhat generous interpretation of its SPD guidance on the 45-degree angle of sight line with respect to no. 142, did not identify an excessive loss of amenity for neighbouring properties for any reason. [name] agree with that stance on balance, the lack of material harm in that regard does not outweigh the harm I have found under the main issue.

My finding on the main issue is decisive to the outcome of this appeal. There is conflict with the development plan. The harm cannot be mitigated by the imposition of planning conditions and it is not outweighed by other material considerations. For the reasons given above and taking into account all other matters raised, I conclude that this appeal should not succeed.