5.3.11 Environmental Sustainability

CONSERVATION FRAMEWORK

5.3.11 ENVIRONMENTAL SUSTAINABILITY

See also:

5.3.4 Ruined cathedral

5.3.5 New cathedral

5.3.6 Repair, maintenance and conservation

HERITAGE CONSIDERATIONS

Coventry Cathedral has a responsibility to future generations to play its part in cutting carbon emissions. Even small actions as part of day to day building management can have an impact on the climate crisis and thought should always be given to whether there is a more sustainable way of achieving the same goal. Climate change also has a direct impact on the Cathedral. Weather events are getting more dramatic and more frequent, putting additional pressure on all building types.

The environmental conditions inside the Cathedral are also considered here, as they can be affected by the external weather conditions and any changes to these.

Pressure for 20th-century buildings such as Coventry Cathedral to become more energy efficient will continue to increase, particularly as existing building services reach the end of their useful life and options for their replacement are considered. The reuse and retrofitting of historic buildings is inherently sustainable but thought must be given to how this can be achieved in a way that does not negatively impact on significance, which includes understanding how Spence originally designed the building to function. Solutions to heating and lighting the building in the 1960s were innovative and very much of their time, which paves the way for new responses to be equally innovative, where appropriate.

VULNERABILITIES AND CONFLICTS

There is potential for conflict between the significance of the Cathedral for its Post-War art and design and the requirements to upgrade or replace original building services. The most pressing issue is heating. This is partly due to the progressive failure of the original system, and partly due to the inefficiencies of the building, with large expanses of glass and extreme fluctuations in temperature. The scope for reducing the Cathedral’s carbon footprint is also hampered by this.

At Coventry Cathedral, the following are potential risks to environmental conditions, built fabric and its associated significance:

• Rainwater laced with de-icing salts is percolating through the open joints in the paving in the porch and potentially effecting the pre-stressed concrete beam buried beneath the Queen’s

Steps.

• Water ingress may also have an impact on the integrity of the pre-stressed concrete roof structure.

• More extreme cold periods causing freeze/thaw damage to stonework.

• Increased extreme weather can impact on the distribution of pests that threaten the integrity of fabric (e.g. woodworm or beetle infestations). • The Sutherland tapestry is not protected from extremes of the heat or UV from sunlight and, at times, is known to significantly expand and contract due to changes in mature humidity. Moths are also a problem.

• Increased rainfall can be beyond the capacity of rainwater goods, resulting in saturation of the stonework.

• The internal rainwater drain pipes are potentially vulnerable to blockage or failure with potentially serious consequences.

• Inefficiencies in the heating system reduce the ability to heat the nave space to a level of ‘conservation heating’ appropriate to the historic fabric.

• The external envelope of the new cathedral is inefficient, and the micro-climates found in many of the interior spaces are often inhospitable.

• Chapel of Christ the Servant – the building envelope is leaking and offers almost no environmental buffering. This coupled with the failed heating system renders it largely unusable.

• The ruined cathedral is exposed to weather externally, with areas that were designed to be internal also exposed. This has resulted in increasing deterioration of organic growth in those exposed areas.

• Environmental conditions in the undercroft and exhibition spaces may be having a harmful effect on the displayed and stored glass from St Michael’s Church (parts of which are medieval).

• The impact on current environmental conditions on fixtures, monuments, furniture etc is not completely understood but the detrimental effect on the organ is known.

CONSERVATION FRAMEWORK

POTENTIAL FOR CHANGE

There is potential to improve the energy efficiency and environmental conditions within the Cathedral, but this process must begin with a clear understanding of the problems, not just the symptoms. Environmental monitoring has been carried out by Tobit Curteis Associates to better understand the link between the micro-climates within the Nave, the mechanical ventilation system and the mechanisms of decay which have been identified with Graham Sutherland’s great tapestry. This will be vital in discussing and agreeing on a conservation approach to the tapestry, as well as other fixtures and fittings.

Climate change and extremes of weather should be considered as part of every repair and redesign of the external envelope to ensure that any future harm can be reduced.

Opportunities to address the impact of climate change and increase sustainability/energy efficiency at the Cathedral include modernising lighting; improving insulation and draught proofing; and investigating sources of renewable energy such as bio-fuels, ground source heat pumps, and solar panels. There is an opportunity as part of a comprehensive rehabilitation and environmental upgrade of the external envelope to the Chapel of Christ the Servant to increase thermal performance of the glazing installation with double or triple glazed units with new glass specified to have UVfiltering qualities.78 There is an opportunity to replace the underfloor heating in the nave with a zonal-system that is more efficient and can be better maintained without damaging the floor in the future. Improving insulation and draught proofing would improve the efficiency of heating systems.

There may also be improvements that can be undertaken to the West Screen to reduce draughts and dust ingress into the interior of the new cathedral. This exercise should be undertaken in tandem with ideas to bring the central double doors back into use as part of the Visitor Route and to also provide physical protection to the lower glass panels.

This is particularly relevant following the vandalism in January 2020. In the long term the bronze barriers should also be removed with alternative arrangements for controlling vehicular access.

There is an opportunity to replace the underfloor heating in the nave with a zonal-system that is more efficient and can be better maintained without damaging the floor in the future.

Where original materials have failed, there is an opportunity to explore the potential to replace or repair materials with more energy efficient alternatives, where this will not adversely impact cultural significance.

78 Kelley Christ, Coventry Cathedral, Report following the Quinquennial Survey 2016-18, Volume II - The New Cathedral MANAGEMENT POLICIES

POLICY 35: Make use of the data which has been collected to make decisions about the future heating of environmental control requests

POLICY 36: Ensure the existing energy performance of the building is understood prior to proposing new efficiency measures. Monitor the efficiency of the building before, during and after the implementation of any measures.

POLICY 37: Consider more energy efficient replacements for failed original systems. Ensure that replacements will have no, or minimal, adverse impact on.

PRIORITY ACTIONS

Action Priority level Owner

Implement the chosen option for the nave heating and assess the impact on the environment before considering further options B Cathedral architect

Priority levels: A – within 6 months, B – within 1 year, C – within 2 years