Appeal 3302143

The appeal is dismissed.

The main parties agree that the proposed single storey rear extension, conversion of barn hip to gable and roof windows are not in dispute. I have no reason to find otherwise and have considered the appeal on this same basis.

The main issue is the effect of the proposed loft conversion and facing gable (the rear extension) on the appeal property and the character and appearance of Berkhamsted Conservation Area (BCA).

The appeal property is a circa [address] dwelling in BCA. First floor accommodation is partly in the roof with small, gabled dormers front and rear, a low eave level and extensive low pitched sloping roof planes. It is similar in design to Nos 1 to 3 [name]. The dwellings in this terrace have not been significantly altered externally so have notable homogeneity and visual coherence. Although different in some respects, such as floorplan, age or detail most other dwellings in this end of [address], and nearby in [address] and [address], are broadly similar in scale, massing or overall form. This distinctive pocket of residential development adds to the significance of BCA.

The rear extension would introduce, or significantly increase the extent of, vertical wall in three elevations of the appeal property. On one side rising above the roof slope and the other side flowing seamlessly into a greatly enlarged and asymmetric (left) flank elevation. A long, rear gabled roof would be virtually the same height to ridge as the existing ridge with a narrow profile close to a significantly raised eave level. Although it would remain flush with the existing ground floor rear elevation, the three-dimensional form of the rear extension would nevertheless project well beyond the plane of the main roof slope, which would almost be entirely obliterated. This would add significant building volume and bulk, more so higher up.

The extension would, therefore, result in a substantial increase in the scale, massing and overall extent of built form in this upper part of the appeal property. It would significantly alter it from a modest one and a half-story building to, essentially, an imposing three-story building at the rear. Such an unduly dominant feature would clearly result in a disproportionate addition to the appeal property. This awkward and incongruous adjunct would also jar with the integrity and uniformity of the terrace as a whole, at odds with important defining features of these dwellings and others nearby.

Though not a through road for vehicles this part of [address] has public pedestrian access. The flank (left) side of the extension would be seen in views from one direction and the nearby bridge over the canal. The rear extension as a whole (and in the context of the entire terrace and adjoining properties) would be noticeable in views from the canal towpath which is a footpath used by the public. Intervening landscaping would not screen these views all year round and, anyway, could not be relied on long term. The absence of any greater public visibility does not mean the absence of intrinsic harm to the appeal property or BCA.

External materials would match the appeal property and the new roof would have a relatively low pitch. However, these considerations do not alleviate or overcome the fundamental incompatibility of the rear extension in this case. I have not been informed that any nearby rear dormers or facing gables are the same, or similar, to the rear extension, especially in height, or that that these are a prevailing feature. The appellant considers that some aspects of the fabric or structure of the appeal property, or nearby dwellings, are deficient in age, design or some details but these are innate properties of these buildings. In any event, the rear extension plainly exceeds ‘enhancement’ or that which might reasonably be required to achieve such outcomes, including in the interests of the character and appearance of the BCA.

I have also been referred to some photographs of buildings elsewhere in BCA. These include upper-story facing gables. However, most, if not all, appear to be in front elevations and are distinctly different types or sorts of buildings; or are not in this particular part of BCA so do not have the same immediate surrounding context. Moreover, most of these buildings appear to have been designed as such, rather than extended. These examples are, therefore, not directly comparable to this appeal.

Taking all of the above into account, I find that the rear extension would have a significant undesirable impact on the form and appearance of the appeal property and render it manifestly out of keeping with the terrace as a whole. This would have a negative effect on the special architectural and historic interest of BCA and, albeit in a small way, diminish the significance of this designated heritage asset. The impact would be localised and as a result would cause less than substantial harm. The proposal would not, therefore, preserve or enhance the character or appearance of this part of BCA or this conservation area overall. Consequently, it would conflict with Policy CS27 of the Council’s Core Strategy 2013. This policy includes that development should conserve and enhance conservation areas and that the integrity and distinctiveness of designated heritage assets will protected.

The rear extension would add new living accommodation and the resulting three-bedroom dwelling could be suitable and more affordable for larger family occupation, as well as increase the stock of such properties. Conversely it would reduce the stock of two-bedroom properties suitable for smaller families or single person occupation. There is, though, no objective evidence of any identified need either way or to explain why the rear extension would result in an ‘optimal’ (as opposed to desirable) use of the appeal property. It would enhance home working conditions for the appellant and his partner but this activity already occurs at the appeal property, so there would be no material change to transport or climate change considerations in this respect. This would, anyway, be a private benefit.

The harm that would be caused by the rear extension would conflict with the Council’s relevant development plan policy. It is consistent with aims of the National Planning Policy Framework to balance meeting specific housing requirements and the amenity of existing occupiers with well-designed, better places to live and to conserve the historic environment; recognising that heritage assets are an irreplaceable resource and that great weight should be given to the conservation of designated heritage assets irrespective of the level of any harm to its significance. Consequently, these are important factors against this part of the proposal and, as such, I give significant weight to these considerations. The adverse impacts of the rear extension would, therefore, outweigh the alleged benefits.

Some different extension options were not preferred and the appellant considers that the rear extension addresses pre-application officer advice. However, the Council made the decision that it did for the reasons set out in its officer report and decision notice. I have determined the appeal on the evidence before me and the individual planning merits of the rear extension.

The rear extension would not accord with the development plan. There are no other material considerations, including the provisions of the Framework, which outweigh this finding. Consequently, for the reasons given above the appeal does not succeed.