The Building Conservation Directory 2022

PROFESS IONAL SERVI CES 1 37 C AT H E D R A L C O MM U N I C AT I O N S T H E B U I L D I N G C O N S E R VAT I O N D I R E C T O R Y 2 0 2 2 the housing development planning permission in February 2021 (see http:// bc-url.com/919 ) on the basis that planning officers were satisfied that there were adequate reserves of Portland stone elsewhere, and on the understanding that the mining consents granted by the former county council were ‘a temporary opportunity in recognition that the site would make an important contribution to local housing need’. The consent made no provisions for the prior extraction of the stone, to the surprise and disappointment of the local industry and the consultees who supported it, the MPA, the English Stone Forum and Historic England. Portland stone is limited to the Island of Portland and was the first ever stone to be registered as a Global Heritage Stone Resource. LESSONS LEARNT Is it the case that stone safeguarding is more effective when the Minerals Planning Authority (MPA) is independent from the local planning authority? The Exeter Cathedral case was dealt with by a county council (Devon), and the planning permission for stone extraction outside the designated MSA in Portland was also granted consent by a county council (Dorset before its abolition in March 2019). Furthermore, the strong support of the MPA in Portland island following its subsequent absorption within the local planning authority had no effect in the decision making of the planning application for the redevelopment of the former Royal Manor School. Cost also emerges as a key factor in the use of matching stone. Exeter Cathedral had also applied in 2013 and succeeded in obtaining planning permission for the extraction of Beer Stone from the Beer Quarry Caves but use of this permission was not feasible because of the cost of setting up the mining operations, which was independent of the small quantities needed. Similarly, cost was behind the decision not to use matching Collyweston slates in the re-roofing of the Grade II listed Tally Ho Inn, despite them being mentioned in the statutory list entry of the building and being available through limited quarrying. Do these two examples demonstrate that some limited quarrying is far too expensive to be viable? If so, what should happen when matching original stone is beyond the financial means of a project? In the case of Exeter Cathedral, an alternative natural stone has been used for some repairs where the original was unavailable. The use of this substitute, a readily available French stone of comparative qualities, was justifiable as this would be consistent with published guidance from Historic England. On the other hand, the replacement of the Collyweston slates with an artificial substitute cannot be accepted as an appropriate approach, particularly as the consideration of other options and a discussion with Historic England does not appear to have preceded the granting of listed building consent. While it is in the local planning authority’s power to grant consents, is this not a clear case where the detailed advice of HE should be sought and given, including the consideration of grant- assistance and how the Strategic Stone Study might be of use in this instance? Recommended Reading National Planning Policy Framework 2021, http://bc-url.com/nppf Government guidance on minerals 2014, www.gov.uk/guidance/minerals British Geological Survey, The Strategic Stone Study Database, http://bc-url.com/ strategic-stone-study Context 154 , May 2018 pp 14–16, Clara Willett and Chris Wood, ‘Finding Stone’ pp 17–19, Emily Harper and Sue Penaluna, ‘Sourcing Stone to repair Exeter Cathedral’ Historic England, Stone Slate Roofing , Technical Advice Note 2005 (2018) Janine Dykes, ‘Collyweston Roofs’, The Building Conservation Directory 2019 ELENI MAKRI MArch BArch RIBA IHBC AABC is the founder and manager of Conservation PD (Planning + Design) (see page 17). Her previous roles include head of the heritage team at the Halpern Partnership (now Formation Architects) and local authority conservation officer. Island of Portland: the entrance to Jordan’s mine (Photo: Albion Stone) Island of Portland: cutting with a diamond saw at Jordan’s mine (Photo: Chris Wood) The Cenotaph in Whitehall, London by Lutyens, 1930: Portland stone has been exclusively used here and on numerous other WWI monuments and graves in the UK and abroad.