NET ZERO | 2050 BUILDINGS Healthcare buildings Steve Merridew, building services engineering director, BDP In the context of decarbonisation, a better question would be: what do you think a typical healthcare estate will look like in 2050? NHS trusts are managing ageing estates with extensive maintenance backlogs and significant carbon footprints. This legacy estate will represent a significant proportion of the NHS footprint in 2050, even after delivery of the New Hospitals Programme (NHP), with its net zero carbon and digital legacy commitments. This is probably the greatest challenge to trusts and their designers. How do we retrofit, and digitally enable, the legacy estate, while completing the transition from fossil fuel-fired and, in many cases, steam heating networks to a modern district infrastructure, allowing for the sharing of heating and cooling energy, while phasing out natural gas in heat and power? An example of addressing the challenges to meet the net zero target is BDPs work with Milton Keynes University Hospital (MKUH), which is looking to increase the capacity of its clinical offer through new, net zero carbon, digitally enabled facilities under the NHP. Its existing buildings and infrastructure are typical of many NHS estates, with accommodation dating from the 1970s, 80s and 90s. While it does not have significant legacy steam infrastructure, the low temperature hot water heating is gas-fired through combined heat and power and conventional boilers. MKUH recognised that meeting its ambitious decarbonisation targets depends on its ability to improve the energy efficiency of its retained estate while decarbonising its heating infrastructure; most importantly, the trust recognised that both requirements are interdependent and interdisciplinary in nature. To help realise its ambition, BDP developed a comprehensive energy and infrastructure strategy, providing a blueprint for the phased retrofit and upgrade of the retained estates, alongside the phased delivery of a resilient, compliant and decarbonised infrastructure. BDP developed an Estates Digital Energy Twin (EDET), calibrated using historic site metering data and coordinated with the capital masterplan and estate strategy. The EDET supported a life-cycle analysis of various energy and infrastructure scenarios, demonstrating that in addition to drastically over sailing the trusts carbon-reduction targets a business-as-usual approach was the most expensive over the strategys life-cycle. The strategy is a live document that is informing decision-making for retrofits and infrastructure upgrade projects, while supporting the objective of connecting buildings delivered under the NHP to a modernised and decarbonised central infrastructure. MKUH is currently overcladding its cardiology building as part of a pilot to sustainably extend the life of its existing facilities, improve energy efficiency, enhance occupant comfort and reduce heat network temperatures to support a phased transition to decarbonised heat sources. Looking to 2050, the typical healthcare estate will have a decarbonised energy infrastructure, after a coordinated phaseout of fossil-fuel energy generation. This will be part of the replacement of buildings to modern healthcare standards or, more likely, an improvement in efficiency of systems and the upgrading of building fabric. Commercial buildings Duncan Price, partner, Buro Happold A typical commercial building in 2050 will be flexible, adaptable, and deliver exceptional health and wellbeing for its occupants, in support of commercial activities that promote social and environmental good. It will have multiple uses to ensure it is well used across the day, week and year, and adds social value, while reducing transport emissions and improving air quality. The commercial structure will have been reused, repurposed or remade from existing materials or zero carbon new materials. These should be environmentally regenerative and net positive in their production, transportation and construction. The building will be supplied with clean, renewable energy from onsite and offsite sources, connected into a smart energy system that optimises production and consumption of clean energy across the city. The building services are likely to be all-electric and powered by a zero carbon grid. It will have embodied the principles of the UK Green Building Council Net Zero Carbon Buildings Framework Definition. Through intelligent design, and thermally appropriate materials, it will be resilient in the face of climate change, and support biodiversity, forming part of an urban green network. We have been working with C40 Cities on how to transition the industry to net zero through application of a Clean Construction Hierarchy. Tier 1: Optimise the use of existing buildings: The use of existing spaces to their maximum potential, to reduce numbers of unoccupied and vacant spaces in the city, will be of prime importance. This might require new approaches to funding and finance, such as increased taxes on unoccupied properties and projects highlighting the potential of a citys underused assets. Tier 2: Retrofit and/or refurbish existing stock: Building owners should do end-of-life demolition assessments to encourage renovation, reuse and adaptive use of buildings, and whole-life embodied carbon assessments to drive design and planning decisions. Refurbishment schemes will be required to improve efficiency of buildings in operation, using low carbon materials and solutions. Cities might need to use their powers on permits, planning and development control, and support education and guidance around reuse and retrofit principles, and new assessment tools and data to support training and upskilling. Tier 3: Build new only if necessary, reducing embodied carbon and following circular principles: Production of new buildings might need a step change in the use of prefabricated, offsite and modular construction methods to reduce waste, improve the environment, and promote a circular economy with the use of bio-based materials and certified timber products, backed by robust Environmental Product Declarations. Contractors will need to switch to zero carbon machinery and equipment. There may be a role for competitions and awards for the use of specific materials and processes, as well as the adoption of new building codes and standards incorporating regulations for Clean Construction design processes. 24 November 2021 www.cibsejournal.com CIBSE Nov21 pp22-24, 26 Net zero future COP26.indd 24 22/10/2021 16:28