Appeal 6004582

The appeals are both dismissed.

The original application form describes the proposal as “provide a glazed link from the house to the barn” but I have used the description from the Council’s decision notice in the banner heading above for reasons of clarity.

The main dwelling is referred to as [name] in the decision notice and the appeal form, but the address should be based on the application form which in this case is 1 and 2 [name]. This is also the list entry name for the listed building.

The main issue for both appeals is the effect of the proposal on the host dwelling and special interest and significance of the [name] listed building known as 1 and 2 [name] and [name] to North1.

1 and 2 [name] were a pair of semi-detached dwellings with a joint outhouse block linked to the two houses by a central wall. They were designed by 1 List entry 1176749 Appeal Decisions 6004582 and 6004276 [name] and built in 1913 as estate houses but have since been converted into a single family home with a single outhouse, although the central wall remains. The main dwelling is single storey with a large roof providing attic level accommodation. It comprises red brick with clay tile roof and tile hanging in the two end gables, with a central chimneystack, several casement windows and panelled entrance doors. The outhouse is subservient to the main dwelling in terms of scale but uses similar materials and design and has been recently extended on the north side.

The rich architectural detailing, the historic use as estate buildings, and the link with a prominent architect from the late 19th and early 20th century contribute greatly to the special interest and significance of the listed building. The outhouse forms a key part of the ensemble, and the survival of the central wall allows one to understand the listed building’s previous use as two smaller dwellings. The space between the main dwelling and the outhouse acts as a small courtyard on both sides of the central wall. The space helps to offset the dwelling from the outhouse and reinforces the relationship between the two structures, thereby contributing positively to the special interest and significance of the listed building.

The proposed timber framed conservatory would occupy most of the courtyard between one half of the dwelling and the outhouse and provide a link between the existing kitchen and ancillary rooms. The principle of a glazed link is not disputed between the appellant and the Council. Subject to good design, I concur that such a link is possible.

The footprint of the proposed extension would be acceptable since a narrower link corridor would create an even smaller and largely redundant courtyard area between the link and the central wall. The use of the extension as additional living space is also satisfactory. However, the traditional timber conservatory design with a pitched roof comparable in shape and height to the outhouse would compete for attention in the relationship between the dwelling and the outhouse when viewed from the west side of the property. The roof would also be visible over the central wall from the other side and so would erode the sense of separation between the dwelling and the outhouse. The insertion of a window in the central wall would appear incongruous in a space that has previously functioned as a separate courtyard for one semi-detached property only.

While the proposal would not be visible from the road, have limited effect on historic fabric, and would ultimately be reversible, it would nonetheless have an adverse effect on the host dwelling and would not preserve the listed building contrary to Sections 16(2) and 66(1) of the Planning (Listed Buildings and Conservation Areas) Act 1990. It would also cause harm to the significance of the listed building.

The harm would be less than substantial but not insignificant. Policy HE1 of the North Hertfordshire Local Plan 2011-2031 (LP) and paragraph 215 of the National Planning Policy Framework (NPPF) require such harm to be weighed against the public benefits of the proposal including, where appropriate, securing its optimum viable use. NPPF paragraph 212 requires great weight to be given to the conservation of designated heritage assets irrespective of the harm, while NPPF paragraph 213 requires clear and convincing justification for any harm or loss. Appeal Decisions 6004582 and 6004276

The proposal would allow for better functional use of the listed building with a covered link between the main dwelling and the outhouse. This could allow the outhouse to be used as ancillary accommodation space for different generations of the same family. However, the listed building appears to be functioning well in its optimum viable use as a dwellinghouse with the outhouse already forming part of that overall use. Moreover, the same functional and family benefits could be achieved through an alternative design given that the principle of a link extension is not in dispute. Therefore, the public benefits would not outweigh the identified harm and no clear and convincing justification exists for the proposal.

I note that The Lutyens Trust are the leading authority on the architect and have raised no objection with the proposed design. The Trust clearly has a wealth of expertise and knowledge relating to Lutyens and his buildings. However, I have assessed the proposal based on how the dwelling and the outhouse function together as part of the overall listed building and have concluded that the scale and form of the proposed extension would not be acceptable.

The Council has indicated that a flat roof and lightweight link with fewer glazing bars would be acceptable. No detailed design is before me and so I cannot comment on the merits of this or any other alternative approach. Nevertheless, it remains open for the appellant to submit fresh applications to the Council for a revised design proposal.

In conclusion, the proposal in both appeals would have an adverse effect on the host dwelling and the listed building with insufficient public benefits. Therefore, it would not accord with [name] D1, D2 and HE1 which require schemes to respond positively to the site’s local context with extensions that are sympathetic to the existing house in terms of matters such as height, form, roof type and materials, and where harm to the significance of a designated heritage asset is outweighed by the public benefits. The proposal would also not accord with NPPF paragraphs 212, 213 and 215.

For the above reasons, and having regard to all other matters raised, I conclude that the appeals should be dismissed.