CASE STUDY: Plot A3 New Bailey
The design of the office building at Plot A3 New Bailey has been developed using the Better Building Partnership’s Design for Performance standard and the RICS Whole Life Carbon assessment methodology to try and achieve the net zero carbon for construction and operational energy use intensity targets. Currently in the design development phase, the scheme will be assessed against these standards at every RIBA stage with the energy and carbon intensity performances report.
As part of the design development a series of structural options were considered and evaluated to reduce the upfront embodied carbon of the scheme, with the early-stage development reducing the upfront embodied carbon by over 25% of typical UK developments.
In terms of operational energy, the design team have already achieved a 50% reduction over Good Practice REEB benchmark performance. The initial Design for Performance assessment indicates that the design is meeting the landlord energy intensity target of 35kWh/ m2/yr and a pathway to the tenant energy intensity target of 35kWh/ m2/yr has been identified. Meaning that the current design is likely to achieve the UKGBC’s 2050 ‘Paris Proof’ operational energy use intensity target for the whole building of 70kWh/ m2/yr.
The limited roof space is being utilised for air source heat pumps and a roof terrace for occupant wellbeing. A small area of PV will be included above the plant enclosures to generate a proportion of the development’s energy requirements. All landlord energy will be purchased to consider the ownership of the Energy Attributes, Renewable Source and Additionality. Information will be provided to the occupiers to enable them to purchase good quality renewable electricity.
Upfront embodied carbon:
- Designing out the basement
- Specifying cement replacements
- Specifying recycled steel for rebar
- Reducing steel weights by optimising the structural grid
- Designing out the curtain walling systems
- Using re-used raised access floors.
Further recommendations are being considered by the design team which have the potential to reduce the upfront embodied carbon by a further 25% to bring it in line with the LETI 2020 embodied carbon intensity target of 600kgCO2/m2.
- Optimised glazing areas of 45% of the facades
- Building fabric performance reduced to near Passivhaus standards with all curtain walling elements designed out
- Reduced cooling plant sizes for optimised year-round performance
- Relaxed summer and winter setpoints, with comfort maintained due to reduced glazing areas
- Enchased zoning and controls optimisation
- Openable windows for occupancy choice and reduce out of hours plant usage
- Demand driven ventilation systems
- Active free cooling
- Air scoured heat pumps for meet all heating requirements
- High efficiency LED lighting with daylight and occupancy controls
On completion the upfront embodied carbon (A1-A5) will be verified, offset and disclosed. Every subsequent year the operational energy (B6) and in use embodied carbon (B1-B5) will be verified, offset and disclosed. This will form part of MUSE’s overall offsetting strategy which will be published on an annual basis.