BREEAM Refurbishment and Fit-Out: Balancing Heritage and Energy Efficiency
A Grade II listed Victorian building is being refurbished to create a boutique hotel. The project aims for BREEAM Refurbishment and Fit-Out Excellent. The building has single-glazed sash windows, solid brick walls, and a slate roof. The local planning authority (LPA) requires that the historic fabric be preserved, limiting changes to the façade and windows. The design team proposes internal wall insulation (IWI) and secondary glazing to improve energy efficiency. However, the IWI could cause moisture issues and is expensive. The energy model shows that without IWI, the building's energy use exceeds the notional building by 20%, failing the Ene 01 credit. The team is considering connecting to a nearby district heating network (DHN) with a low-carbon factor of 0.05 kgCO2e/kWh, but the connection cost is high. The client is concerned about the BREEAM cost and the potential impact on the heritage value. The project is in the UK and uses BREEAM UK Refurbishment and Fit-Out 2014.
1. What options are available to meet the Ene 01 credit while respecting the heritage constraints, and how should the assessor evaluate them?
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The assessor should consider a combination of measures: 1) Secondary glazing is often acceptable in listed buildings as it preserves the original windows, improving thermal performance without altering the façade. 2) Internal wall insulation may be acceptable if detailed moisture risk assessment shows no harm; alternatively, use of breathable insulation materials could mitigate risk. 3) Connection to the DHN provides a low-carbon heat source, significantly reducing CO2 emissions and potentially compensating for the building's fabric inefficiency. The assessor should evaluate each option against BREEAM criteria: Ene 01 requires a reduction in regulated energy use or CO2 emissions compared to the notional building. The DHN with a low carbon factor can help achieve the reduction. The assessor should also consider the heritage impact and LPA requirements; BREEAM encourages a balanced approach. The assessor should recommend a combination of secondary glazing and DHN connection, as these are likely to be acceptable to the LPA and can achieve the required reduction. The energy model should be updated to include these measures, and the assessor should verify that the DHN is a financially viable and reliable solution.
2. How should the assessor address the potential conflict between BREEAM requirements and heritage preservation, and what evidence is needed?
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The assessor must ensure that BREEAM requirements do not compromise heritage value. BREEAM Refurbishment and Fit-Out includes credits that recognize the constraints of historic buildings; for example, Man 03 (Responsible construction practices) and Mat 03 (Responsible sourcing) may be adapted. The assessor should document the heritage constraints and the LPA's requirements, and demonstrate that the chosen measures are the best available option. Evidence could include a heritage impact assessment, moisture risk assessment for IWI, and correspondence with the LPA. The assessor should also check if any BREEAM credits have specific exemptions for historic buildings. For Ene 01, if the notional building target cannot be met due to heritage constraints, the assessor may need to use the BREEAM 'exceptional' approach, but this is rare. The assessor should focus on achieving the required reduction through allowable measures and provide a clear justification for any deviation. The final decision should balance the BREEAM rating with the preservation of the building's significance.