Appeal 3272834

The appeal is allowed and planning permission is granted for the demolition of the rear of the existing side extension and its replacement with a new side/rear extension at [site address] in accordance with the terms of the application, Ref 21/0203/HSE, dated 14 January 2021, 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: SV 001 (Existing plans), SV 001 (Existing and proposed plans), SV 002, SV 003, SV 011 and SV 012.

No development other than demolition works shall take place until details of the materials to be used on the external surfaces of the building hereby approved have been submitted to, and approved in writing by, the Local Planning Authority. The development shall thereafter be implemented in accordance with the approved details.

Prior to the first occupation of the development hereby approved, details of the proposed green roof shall be submitted to, and approved in writing by, the Local Planning Authority. The green roof shall be implemented in accordance with the approved details prior to the first occupation of the development and shall be retained as such thereafter. Should any part of the green roof be removed, die, become severely damaged or diseased within five years of the completion of the development, it shall be replaced in accordance with the approved details.

The roof of the extension hereby permitted shall be used only in connection with the repair and maintenance of the building, and shall at no time be converted to, or used as, a balcony, roof garden or similar amenity or sitting out area.

The main issue is the effect of the proposed development on the character and appearance of the host property and the area, including whether it would preserve or enhance the character or appearance of the Monken Hadley Conservation Area.

Many of the houses in [address] were designed by local architect, [name]. The buildings here are of substantial proportions and set back from the road behind landscaping. They are typically of an individual appearance, but finished in a similar palette of materials, and in an Arts and Crafts style, with attractive features such as ornate masonry, window detailing, bold chimney stacks, and overhanging eaves.

I understand that 16 and [address] were originally designed by Waymouth for his own use as one house. The building has a predominantly pitched roof including various gables, and is finished in masonry and timber. It retains many original design features typical of its era and style. The building is described by the Council as locally listed, and given its architectural interest, I agree with the parties that it is a heritage asset as defined by the National Planning Policy Framework 2021.

For the above reasons, this building, together with others in [address], contributes to the significance of the Monken Hadley Conservation Area. Section 72(1) of the Planning (Listed Buildings and Conservation Areas) Act 1990 sets out in respect of development affecting conservation areas, that special attention shall be paid to the desirability of preserving or enhancing their character or appearance.

The Monken Hadley Conservation Area [name] 2007 (‘MHCACA’) states that extensions here need to be thoughtfully designed, relate to or appear as though they are part of the original development, and should sit comfortably in their setting. However, it notes that new development need not be traditional but can provide a high quality contrast, and that contrasting materials may also be acceptable.

Most of the single storey side extension at No 16 would be replaced. Whilst its facing materials broadly reflect the original property, it has a higher eaves, lacks some of the host’s detailing, has a rather complex roof form, and has simple UPVC windows and doors.

The proposed extension would be glazed within slim metal frames to the rear and one side; and it would have a flat sedum green roof. Its design and form would thus be markedly different to both the extension it would replace and to the host property. However, its form and materials would give it a high quality contemporary look, and unlike the existing extension which seeks to broadly mimic the original property, it would successfully distinguish between the two. Additionally, its largely see-through appearance would allow the original building to dominate.

Although the proposal would be wider and would extend deeper into the garden than the existing extension, its height to the rear would be lower, and its glazed side would be set away from the host’s principal rear face. The glazed facades would give it a very lightweight appearance, which would significantly limit its overall mass. Its footprint, height and scale would be much smaller than the host property.

For all those reasons, the scheme would appear harmonious in its setting and appropriately subordinate to the host property, in accordance with the Council’s Residential Design Guidance Supplementary Planning Document 2016 (‘SPD’) and, although the property is not statutorily listed, with the general advice at paragraph 2.11 of the IHBC Guidance on Alterations to Listed Buildings 2021.

Collectively, and in general terms, Policies CS1 and CS5 of the Barnet Local Plan Core Strategy 2012, and Policies DM01 and DM06 of the Barnet Local Plan Development Management Policies 2012, seek to preserve and enhance local character; to create a quality environment through the highest standards of urban design; and to protect the Borough’s heritage, including its conservation areas and locally listed buildings.

As it would appropriately respect the host property and would preserve the character and appearance of the Monken Hadley Conservation Area, the scheme would not conflict with those policies; nor with the advice in the SPD and the MHCACA.

Summing up, the scheme would not harm the character and appearance of the host property or the significance of the Monken Hadley Conservation Area. The appeal will therefore be allowed.

Turning to the matter of conditions, I have imposed the standard time limit condition 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 the character and appearance of the host property and the area, details of the proposed facing materials, and the proposed sedum green roof, are required. However, as the plans do not indicate that changes to hard surfaced areas are proposed, I have not included the reference to that in the Council’s suggested condition.

In order to protect neighbouring occupiers’ living conditions, and given its elevated position close to the common boundary, a condition is necessary requiring that the green roof shall not be used as an outdoor amenity area.

Finally, the Council has suggested a condition requiring the submission and implementation of tree protection measures. However, its delegated report acknowledges that no impact on trees or soft landscaping is foreseen. Having regard to the scheme’s context as illustrated by photographs in the Planning Statement, I see no reason why significant trees would be impacted by the proposal. I have not therefore imposed that condition.

For the above reasons, and having regard to all other matters raised, the appeal is allowed.