Jon Nuttall, Associate Director
Putting a plan in to action.
In part 1, we introduced our 6-step Roadmap to a Net Zero Carbon hospital. These stages align with our broad approach to achieving Net Zero look at early design, carried through to construction and operation.
By simplifying the process, and making each stage accessible and easy to understand, we can develop low-energy facilities that are ready for the future of healthcare.
In this instalment, we will take a closer look at our approach, and the importance of each step.
Step 1: set clear targets and benchmarks.
No two hospitals behave the same and should, in turn, be treated as individuals. We believe that, to start, every building’s energy requirements need to be accurately measured.
To achieve accurate benchmarks and bridge the Performance Gap, we must have full building energy modelling, credible whole life cycle analysis and reliable data.
To make this possible, we are collating annual energy use from existing NHS hospital buildings. We are also having early dialogue with the hospital trusts, local city councils, energy providers and other stakeholders to clearly define the targets that achieve realistic and tangible savings in terms of energy and carbon footprint.
Step 2: optimise and reduce.
The next step is the careful analysis of the environmental and climate context of the site. This can reveal where the greatest potential for harnessing the benefits of passive design is.
At early concept stages, we determine climate-sensitive design drivers by studying the weather data, site microclimate, solar orientation and wind direction. Through this early analysis, we can make well-informed, data-based decisions at very early concept design stage.
Step 3: lower climate impact.
To progress into the third stage, a Net Zero Carbon hospital design must track both operational carbon and embodied carbon. After establishing a clear carbon benchmark and an optimised building form, the next step is to design the most efficient energy systems and minimise the operational demand and the embodied impact of the structure. The structural design should be challenged and options for lower embodied impact should be sought; use of materials with a lower carbon impact such as timber, low carbon concrete etc.
Early architectural design analysis can then be integrated into detailed engineering energy models, and be used to accurately measure performance, budget and whole life cycle assessments over time.
Step 4: reuse and generate.
Once the preferred design has been developed, we must consider aspects that promote the principles of circular economy through reusing, recycling and regeneration.
There are a variety of opportunities for hospitals, including the integration of renewable onsite energy, ground and air source heat pumps, SUDS, blue and green roofs, and rainwater harvesting.
DfMA and MMC strategies can also have significant benefits. They enable an end-of-life reuse/ recycling potential that can mitigate an initial higher embodied carbon footprint.
Step 5: measure and offset.
At this stage a whole life cycle carbon analysis should be carried out using the RICS standard method of calculation. The design intent must also aim to utilise less material finishes without compromising the quality of internal spaces.
Sustainable materials must be sourced from supply chains that have committed to transparent environmental product declarations and operate a business that mirrors the NHS’s Net Zero 2050 and RIBA 2030 targets. Following this, any residual carbon from the whole life analysis can then be offset through a certified carbon fund.
Step 6: monitor and improve.
Operators are often given a building with little training or insight as to how it was designed and how the systems work. Management teams should be included in discussions around energy targets, design and servicing strategies, allowing them to learn and understand about the systems and their seasonal variance.
This allows us to identify where energy consumption can be reduced and inform the development of NHS Estates across the UK for a Net Zero Carbon future.