Appeal 6002780

The appeals are dismissed.1

No. 51, part of grade II listed nos. [address],2 falls within the Marlow Conservation Area (at its northern fringe). The property is a mid-terrace house, which the list entry indicates traces its origins to the late eighteenth or early nineteenth century. It appears quintessentially a building of that era (as are others within the Conservation Area). The principal elevation of no. 51 is similar to the other properties completing the terrace, notwithstanding certain variations on a theme and latter alterations. Each has sash windows at ground and first floor beneath segmental arches, set within something of a red-to-polychromatic brick facade with a peppering of vitrified bricks.

The list entry states that, at that juncture, the listed building had an ‘old slate roof’. That remains true of nos. 47, 51 and 53, but not of no. 49. I am told the roof of no. 49 is now of Spanish slate. There is, however, no indication that the current nature of the roof there benefits from listed building consent. A chimney also appears to have been removed at the party wall between nos. 49 and 51, in respect of which there are equally no records before me.3 Were it not for the roof tiles at no. 49, and the absence of a central chimney at the terrace, I would agree more fully with the observation at paragraph 3.4.1 of the appellant’s Heritage Statement that the listed building ‘holds architectural significance in the sense of the unaltered design and uniformity of the overall structure’.4 1 Notwithstanding the definition of development in planning terms under section 55 of the 1990 Act, and any permitted development rights under the Town and Country Planning (General Permitted Development) (England) Order 2015 as amended. 2 List entry no. 1332378 (first listed on 31 January 1974). 3 As shown in photograph 3 in the associated structural report (Structures Made Easy Ltd., 7 August 2025). 4 Brindle & Green, ref. BG25.358, notwithstanding that appears to be in draft. Appeal Decisions 6002779, 6002780

In all likelihood the listed building emerged as part of what might be termed the historic economic heyday of Marlow founded on trade along the Thames (before that locus gave way to Victorian affluence and, later, commuting). The Conservation Area Character Survey of 2004 explains how ‘Marlow was thus very much a working riverside town well into the nineteenth century with many cottages occupied by river workers...’. Although no. 51 is some distance from the Thames, it is emblematic of that era. It is not too much of a leap to surmise that Welsh slate historically made its way here by water before rail. There is no dispute that the roofs of the original elements of nos. 47, 51 and 53 are of Welsh slate, as typifies late eighteenth century construction. Welsh slate is appreciable visually on account of its mid tone and purplish hue, with subtle variances in those qualities between slates.

Despite the description of the scheme as in the banner headings above, as set out in paragraph 6.3 of the appellant’s appeal statement, the intention is to use Spanish slate only at the rear roof slope at no. 51 (in respect of which there is, I accept, scant visibility given that faces towards the rear garden of no. [address]). [address] facing roof slope would be repaired entirely in Welsh slate or original ridge tiles, either with slates currently present there or which would be transposed from the rear roof slope. Details of alterations to the roof structure, to forestall any further deterioration, are set out in the appellant’s Planning, Design and [name] (in short making the roof structurally sound by way of installing new rafters, battens, and breathable roofing membrane).5

Notwithstanding the evidence before me, and the nature of the proposal here, the appeals turn principally on a question of theory. Put neutrally, that is whether the replacement of historic fabric with somewhat comparable modern materials would adversely affect special interest or significance? The answer, almost invariably and in this instance, is that it would.

Inherent in my reasoning above is that, albeit in a modest sense, no. 51 authentically embodies history in physical form. That is in its materials, aesthetic, craftsmanship and the intangible forces those characteristics attest to. Irrespective of visibility, removing historic fabric and replacing that with an imported product with no relationship to the history which led to the establishment of the listed building would reduce integrity or significance. Visually there would be an appreciable difference too. Albeit in respect of a different elevation, the roof at no. 49 illustrates that there is a clear disjuncture between the nature of Spanish slate and Welsh slate. There and invariably, the former tends to be darker, approaching monochromatic, and almost entirely regular in appearance. The adverse effect of the scheme would therefore not be purely abstract, but perceptible.

Even if that harm might reasonably be said to be at the very lowest end of a spectrum within the categorisation of less than substantial harm within the phraseology of paragraph 212 of the National Planning Policy Framework (published 7 February 2025, the ‘NPPF’), there would still need to be clear and convincing justification for it (NPPF paragraph 213).6 That is simply not in evidence. [name] accept that the roof of no. 51 is in need of repair,7 and that the scheme has sought to maximise use of existing slates, the sole justification for using Spanish slates specifically appears to be at paragraph 6.4 of the appellant’s appeal statement which is that the proposed approach ‘encourages maximum retention of fabric and allows for sensitive matching materials where original materials are no longer viable’. There is nothing behind or beyond that. 5 The scheme being illustrated on plan no. ‘TRD-22435-A1/01’. 6 The appellant’s Heritage Statement appearing to foresee that such a finding would be logical in setting out that ‘the historical and architectural value of the listed building will be minimally impacted’. 7 [name] was unable to assess the condition of the roof at no. 51 internally, as shown in the associated structural report referenced above, much of the roof structure appears relatively new, notably ceiling joists and sarking. Appeal Decisions 6002779, 6002780

Fundamentally there is no substantive justification as to why the benefits of the scheme are contingent upon using Spanish slate as opposed to contextually and historically appropriate Welsh slate. I therefore conclude that the scheme would conflict with the clear expectations of sections 16(2) and 66(1) of the LBCA, with the relevant provisions of policies CP9, CP11, DM31 and DM36 of the extant Wycombe District Local Plan (adopted August 2019) and with NPPF paragraphs 213 and 215 insofar as seeking to appropriately safeguard the special interest and significance of no. 51 is concerned.

As above, having considered the development plan as a whole as necessary along with all other relevant material considerations, I conclude that the appeals should be dismissed.