There have been many recent schemes to install underfloor heating in places of worship and the SPAB is extremely concerned that irreversible damage is being caused to important historic buildings as a result. Installations are also often failing to meet user expectations. This document is intended to highlight considerations that should be borne in mind by those contemplating whether or not to install underfloor heating in a historic church.
It is important that historic churches are used, cared for and survive. This will often result in a need for heating to provide comfortable conditions for users. However, there are many different potential heating systems and careful thought and design will result in an appropriate solution for most situations without significant loss of historic fabric.
Underfloor heating uses embedded pipes or cables beneath a finished floor so that heat radiates from floor level. Its installation will inevitably involve removal and loss of building fabric and finishes.
The floor in any church is an important element of its structure, one with which its occupants and users are in contact and which can often show subtle patterns of wear and use over generations. Formed from a variety of materials, floors can almost imperceptibly speak of age and the continual passage of others before us. It is only when historic floors have been destroyed that the significance of the loss is recognised by many, but by then it is too late.
An underfloor heating system may be concealed from view but it has a major invasive impact on the historic build-up of the floor and on adjacent architectural features, for example, the bases of pillars. The installation of such systems is highly inappropriate in historic floors, or where there are burials and archaeological remains due to the loss or damage caused. There are numerous existing publications that make these points but, in spite of this, many historic floors (and the archaeological remains below them) have been destroyed by the insertion of underfloor heating. The reasons for choosing underfloor heating in such situations, and against published guidance, are not clear.
When assessing the appropriateness of any form of heating the following items are amongst those that need to be considered:
The arguments for and against installation of underfloor heating need to be weighed up thoroughly prior to a decision to install this system. The principal advantages are that it can provide warmth over a long period with gradual warm-up and cool-down, and link well with renewable technology. However, underfloor heating is not appropriate in most historic churches and the disadvantages include:
The Society therefore urges anyone contemplating installing an underfloor system to firstly recognise and understand the significance of the existing floor(s) – their intrinsic interest, historical importance and the contribution they make to the building overall, as well as considering the potential impact on the remainder of the building structure. In historic churches, underfloor heating should only be considered in exceptional circumstances and where there is clear and completely convincing justification.
General guidance and advice on the options for heating historic churches may be obtained from one of the following sources:
British Standards Institution (2011) Conservation of Cultural Property – Indoor Climate. Part 2: Heating Churches, Chapels and Places of Worship, BS EN 15759-1:2011, London: BSI
ChurchCare (2013) Choosing the Right Heating System [guidance note]. Retrieved from http://www.churchcare.co.uk/images/Guide_to_choosing_the_right_heating_system.pdf
Induni, B (2015) ‘Sustaining Heating in Places of Worship: Physical, Social, Organisational and Commercial Factors as Determinants of Strategic Decision-Making and Practical Outcomes’. In O Prizeman (ed) Sustainable Building Conservation: Theory and Practice of Responsive Design in the Heritage Environment (pp219-245). Newcastle upon Tyne: RIBA Publishing