In the recent consistory court case Re All Saints Woodham  ECC Gui 1, the petitioners sought to install a new underfloor heating system, on which the Chancellor noted:
“. The need for an adequate heating system is uncontroversial. The most efficient option is to use an underfloor heating system supplied by Jupiter Underfloor Heating to replace a broken and inefficient hot-air system. This means relaying the floor in the nave and Lady Chapel. That in the nave is constructed of wooden floorboards, that in the Chapel is block-flooring”.
The issue before the court was whether the floorboards in the nave should be replaced by a tiled floor and the block flooring in the Chapel should be replaced by a stone floor, as the petitioners wished, or whether the existing flooring should be reinstated where possible and, where not, a new wooden floor inserted to replicate the old .
The Statement of Significance noted that there would be a visual impact by changing the flooring material from wood, but this would be mitigated by having a tile design in keeping with the rest of the church and echoing the church’s Arts & Crafts heritage . The Victorian Society (VS) expressed reservations about the use of a tiled and limestone floor in preference to the reinstatement of wooden flooring, noting that the existing woodblock floor is characteristic of the Arts and Crafts nature of the church and contributes to the well-preserved interior of the building.
In addition to these aesthetic considerations, the VS commented on the “discernible effect on the acoustics of the building” and recommended that the option of installing woodblock floor over underfloor heating was explored. It stated “[w]hile the installation is slightly more difficult…it does have a superiority over tile as the thermal qualities of wood mean that, once warm, heat is retained for longer”.
With regard to the acoustics, the opinion of the PCC’s Quinquennial Inspecting architect and its own Director of Music was that a tiled or stone floor would be more likely to sharpen and improve the acoustics, than be to their detriment . Furthermore, the VS assertion that the Jupiter system had been installed at St Thomas, Telford Park was incorrect .
More importantly, the petitioners reproduced information on the thermal properties of flooring provided by the Senior Project Consultant at Jupiter, who indicated that there were several components to consider when comparing wood and tile as floor finishes within the context of the project: retention of warmth; thermal resistance; and the suitability over underfloor heating . These considerations are reproduced here, and include the only references in the judgment to the use of a heat pump. Whether the scheme under consideration by the court includes the installation of a heat pump is not specified.
The VS’s opposition to the tiling design and the response by the parish were discussed  to . The Chancellor noted:
“. The design of the proposed tiling was, however, a matter upon which there was both time and advantage in having the advice of the Victorian Society as to the form of the most suitable design. I stated in a Memorandum to those concerned that the DAC or members of it should be invited to contribute. I therefore delayed the grant of the faculty until the CBC has been consulted and the petitioners and their advisers had had the opportunity of meeting with the Victorian Society to discuss the final design of the tiling”.
The Church Buildings Officer (Conservation) of the Church Buildings Council stated that the Council was content with the justification for tiling instead of wooden flooring in this context and was content to defer to the DAC’s preference for the quieter arrangement for the nave floor, with the simple horizontal tiling”.
The Chancellor granted a faculty for the installation of the underfloor heating system to be installed below a tiled floor in both nave and side chapel in accordance with the design that had been agreed as the most suitable . However, since £118,000 funding was still being sought, he made it a condition of the grant that no contract for the works is to be entered into unless 90% of the contract price is either to hand or pledged.
Whilst not addressing the “net zero” issue directly, or even the heat source for the underfloor heating of the church, the case Re All Saints Woodham nevertheless raises a number of important issues. The recent ELJ paper by Jaqueline Humphreys* stressed the need for expertise in carbon reduction and environmental issues, and here such expertise was clearly required by the PCC, the DAC and the court to assess the different claims relating to the use of wood flooring. In this respect, whilst the statement from Jupiter relates to the operation of underfloor heating,
“The reduction in thermal resistance [of a tiled flor] will allow the heat pump to be operated at a significantly lower flow temperature whilst offering the required heat output. This lower flow temperature allows the heat pump to operate at a greater coefficient of performance, reducing the electricity required for the long-term”.
With regard to the comparison of the thermal properties of wood vs tiled floors, their performance in a practical situation must be taken into considered, such as ensuring a thermal output (i.e. >50W/m2) “to reliably warm the heavy building fabric and air present in historic church buildings”, which is difficult to achieved with wood flooring.