Sustainability Report

All sustainability information was provided by Angus Goodwin, Associate Director at ZMMA.

IES VE 2019 environmental modelling software was used to produce an energy model, with results calibrated against historic gas and electricity consumption derived from utility bills. Carbon emissions factors were applied to enable comparison between baseline and modelled performance (Electricity: 0.138 kg CO2e per kilowatt-hour, Gas: 0.184 kg CO2e per kilowatt-hour).

Based on this modelling, the proposed design improvements for the main Museum building result in an overall carbon saving of 5.99 tonnes of CO2e per year. This represents a 25 percent improvement on the existing building elements and exceeds the performance requirements set out in Part L of the UK Building Regulations.

A two-pronged approach to decarbonisation was adopted, addressing both embodied carbon in construction (including waste reduction) and reductions in operational energy.

The strategy for reducing embodied carbon in construction included the following measures: 

• Maximising the use of local contractors.
• Retaining as much of the existing building fabric as possible and limiting new construction. The principal architectural interventions involved the removal of inappropriate modern additions, including non-historic internal walls and the creation of new voids within existing floor structures. A limited number of carefully selected new elements were introduced, including a new raised timber floor within the Wool Hall.
• Repurposing existing building fabric and materials wherever feasible. For example, existing timber wall cladding was reused throughout Scaplen’s Court.
• Minimising the use of high embodied carbon materials. Lime-based mortars were used in place of cement-based alternatives. Timber was prioritised throughout the project, including Douglas Fir- and English Oak-framed structures as well as structural timber for the raised floor in the Wool Hall. The use of steel was limited to small connection brackets where required.
• Using bio-based insulation materials, including sheep’s wool and wood-fibre panels, and specifying locally sourced Purbeck stone for museum flooring, lift shaft cladding, and window sills. Low-embodied energy and carbon-negative flooring materials, including Marmoleum and recycled terrazzo, were also selected.

Material choices included:

• Display plinths and panels constructed from Richlite, a sheet material made from recycled paper.
• Graphic panels fabricated from recycled aluminium.
• Graphic elements produced using cotton-based calico fabric.
• General minimisation of materials requiring painted or powder-coated finishes.
• Object plinths manufactured from natural cork.
• A flexible display system constructed from Spruce Triply, a layered timber panel supplied by Winwood.

The approach to decarbonising operational energy included:

• Insulation upgrades to the roofs of the Wool Hall and Oakley’s Mill.
• Internal wall insulation at fourth-floor level — where the conditioned temporary exhibition galleries are located — and within the Wool Hall.
• Installation of double glazing to previously shuttered external openings within the Museum walls.
• Replacement of single glazing throughout the buildings.
• Installation of carefully selected slate-tile–like photovoltaic cells on the roof of Oakley’s Mill.
• Improvements to lighting and heating control systems.
• Replacement of existing lamps with a fully LED-based lighting scheme.
• Reduction in the extent of mechanically conditioned gallery spaces.
• Increased reliance on passive ventilation strategies.
• Introduction of an electric conservation heating strategy in other areas.