Appeal 3325886

The appeal is allowed and planning permission is granted for the erection of a part single/part double storey rear extension, and changes to the fenestration following demolition of the existing garage at [site address] in accordance with the terms of the application, Ref 6/2023/0566/HOUSE, dated 13 March 2023, 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 drawings: 3333 PL 31, 3333 PL 32, 3333 PL 33, 3333 PL 34, 3333 PL 35 and 3333 PL 36.

The materials to be used in the construction of the external surfaces of the development shall match those used in the existing building.

The proposed first floor windows in the southern elevation of the dwelling shall be obscure-glazed to a level equivalent to [name] 3 or above and non-opening unless the parts of the window which can be opened are more than 1.7 metres above the floor of the room in which the window is installed, and shall be retained in that form thereafter. Obscure glazing shall not include applied film or one-way glass.

The Welwyn Hatfield Local Plan 2016–2036 was adopted in October 2023 (‘LP’). As a result, the policies in the Welwyn Hatfield District Plan 2005, which are referred to in the Council’s decision, have been replaced, and I have had no further regard to them. The appellants were given an opportunity to comment on the LP policies during the course of this appeal.

Having regard to the LP policies cited in the Council’s email dated 19 October 2023, Policy SP 10 refers to sustainable design and construction, Policy SP 3 to Green Belts and the settlement strategy, Policy SADM 11 to amenity standards, and Policy SADM 12 to servicing requirements. They are thus of little, if any, relevance to the main issue in this appeal.

The main issue is the effect of the proposal on the character and appearance of the host property and the area, including whether or not it would preserve or enhance the character or appearance of the [site address] Conservation Area (‘the WGCCA’).

Section 72(1) of the Planning (Listed Buildings and Conservation Areas) Act 1990 states that, in respect of development affecting conservation areas, special attention shall be paid to the desirability of preserving or enhancing their character or appearance. The National Planning Policy Framework 2023 (‘Framework’) sets out that any harm to the significance of a designated heritage asset, such as a conservation area, should require clear and convincing justification.

Other than in the context of masterplanning of large sites, and a reference to Conservation Area Appraisals, none of the LP policies cited in the Council’s email refer to the impact of proposals on the significance of conservation areas. However, LP Policy SP 9 sets out a general requirement for high quality design which is informed by, and responds to, the site’s character and context.

Mannicotts lies within the extensive WGCCA. Neither the Council, nor [address] Services refer to the Conservation Area Appraisal for this designated heritage asset. However, I observed that the houses in this road are detached and set well back from the highway behind gardens on spacious plots, thus giving the area an attractive landscaped and spacious appearance. The buildings are fairly varied in terms of their form and scale, but are typically finished in a cohesive palette of light render, clay tiles and masonry.

As evidenced by the aerial view at paragraph 3.14 of the Grounds of Appeal, No 2 has a considerably smaller footprint compared to many of the other properties in Mannicotts, many of which have had significant extensions to the rear. That includes Nos 3 and 4, both of which have large two storey rear projections. Whilst some extensions may pre-date the adoption of the Council’s Supplementary Design Guidance 2005 (‘SDG’), they nonetheless form part of the area’s prevailing character.

The proposed extensions would be mainly sited to the rear on this large plot. The longer of the two storey extensions would be set in slightly from the host’s southern flank wall, thus providing a degree of articulation, and both it, and the shorter two storey extension to the north, would be set down below its ridgeline. Although the total volume of the proposed extensions would be considerable, as illustrated by drawing no. 3333 PL 32, they would project no further to the rear than the broadly similar scale extensions adjacent at No 3.

Both proposed rear extensions would have a hipped roof to reflect the form of the original building, and they would be faced in matching painted render, brick and clay tiles. The front face of the host, particularly its form, prominent chimneys, and spacious, landscaped setting, would be largely unchanged. Consequently, and in the context of the diverse form and scale of the other buildings in Mannicotts, the extensions would not appear out of place.

The scheme includes proposed changes to the host’s fenestration. However, drawing nos. 3333 PL 33 and 3333 PL 34 show that to the front and sides, the size and general appearance of the windows would remain broadly unchanged. In terms of their detailed design and materials, the [address] Retrofit Plan states that the existing steel-framed Crittall windows could be replaced by double-glazed windows by the same manufacturer, but the application form and Grounds of Appeal set out that the existing timber and metal windows would be replaced with white aluminium.

Whilst the Council maintains that such contemporary style windows would not harmonise with the traditional character of the building and the area, I observed on my visit that the windows and other openings in Mannicotts are varied in terms of their detailed design and materials. From the limited evidence before me on this matter, I am not persuaded that the proposed fenestration would be unsuitable.

For the above reasons, the scheme would not conflict with LP Policy SP 9. Having regard to the advice at paragraphs 2.4 and 5.2 of the [name] am satisfied that the scheme would complement and reflect the design and character of the dwelling, that it would be broadly subordinate to it, and that it would respond to the form and pattern of existing development and would not harm the sense of place.

Consequently, the scheme would harm neither the character and appearance of the host property, nor the area. Having regard to the statutory test and the Framework, the scheme would preserve the character and appearance of the WGCCA when considered as a whole.

Turning to the matter of conditions, I have considered those suggested by the Council against the Framework’s tests. I have imposed the standard time limit and, in the interests of certainty, a condition requiring that the development be carried out in accordance with the approved plans. In the interests of good design, a condition is necessary requiring that the external surfaces of the development match those in the existing building.

In order to protect the living conditions at No 3 and to ensure appropriate levels of privacy, a condition is also necessary requiring the proposed new windows in the dwelling’s first floor southern elevation to be obscurely glazed and predominantly non-opening.

Finally, the Council has suggested a pre-commencement condition requiring the submission and approval of a hard and soft landscaping plan in order to protect the character and amenity of the area and to provide ecological, environmental and biodiversity benefits. In that regard, LP Policy SP 10 states that proposals that adopt sustainable design and construction principles will be supported.

However, given that the proposed development would be largely to the rear where, as I observed and as illustrated by drawing no 3333 PL 31, significant trees and hedgerows would be a considerable distance away, and as the application form states that none will need to be removed, I am not persuaded that such a condition is necessary in order to comply with relevant development plan policies. I have not therefore imposed it.

Summing up, the scheme would not harm the character and appearance of the host property or the area, and the significance of the WGCCA would be preserved. Consequently, having regard to all other matters raised, the appeal is allowed.