SUSTAINABILITY
Why sustainability is an essential part of the design brief
Zeb Ahmed, chief executive of BES, has for some years been pushing for culture change, encouraging a change of focus from capex costs to whole-life costs by investing in specification decisions that will reduce energy consumption
as the Climate Change Levy (CCL) and EU Emissions Trading Systems (EU ETS), is also likely to become stricter.
The other driver is the need to measure
environmental performance as part of corporate and social responsibility (CSR), because evidencing performance affects share price, ability to win contracts and brand. The challenge is that any carbon reduction must be delivered without sacrificing the high standards of quality assurance, compliance or safe working conditions. The answer is in a creative and collaborative design process from concept to completion, which balances commercial and sustainability goals and considers the cost throughout the asset’s lifecycle. This approach requires rethinking how we embed sustainability goals at every level, beginning with process design. But energy efficient process design begins much earlier. Currently, even projects that consider sustainability at process design stage, only do so when the process is commercialised, that’s when there’s a financial and reputational benefit to creating efficiencies and reducing emissions. The reality, however, is that is often too late.
S
mart design strategies and digital modelling tools provide a clear and accurate evidence-based business case for long-term savings and ought to be enough to drive positive change.
But sustainability driven processes, building services and architectural solutions can often be more expensive at capex, and neither extended payback periods nor 20-year energy savings appear on a five-year financial plan. Nevertheless, the spike in energy prices, concerns about future cost volatility and reliability of supply, are likely to see future investment decisions that prioritise energy efficiency to reduce costs over the asset’s lifespan. Even if a project is too capex constrained to enable enhanced sustainability at
initial design and construction, part of the engineer’s role is to consider how design strategies can deliver the potential for retrofitting of energy efficient improvements during the service life of the asset. Mandatory Carbon Reduction Plans (CRP)
are already required for public sector projects valued at £5m or more and, based on the premise that regulatory measures imposed on the public sector are often rolled out to the private sector too, those considering development projects should start preparing now for CRP accountability in the not-too- distant future.
Alongside the likelihood that CRPs will be
introduced for private sector-built assets, legislation in place to drive environmental best practice for commercial facilities, such
Sustainability must be considered from the R&D phase, no matter how small scale the process. Indeed, the sustainability considerations embedded in process design during this phase may not yield any energy or carbon reduction benefits, but the efficiency prizes will be won when the process is scaled up.
Another common issue is over-specification. By optimising the mass and energy balance through working alongside scientists, engineers can influence the built solution at RIBA stage 0 (concept). We can then provide optioneering, comparing a capex-based cost model with whole life costs and payback period on the sustainability elements to support evidence- based decision making with modelled data on energy costs. Waste reduction and resource utilisation are fundamental principles of improved energy efficiency. Where continuous processing is appropriate, this enables improved energy efficiency by avoiding the energy required to bring the process to temperature. However, sustainability must be achieved aligned to operational parameters and continuous processing can often be at odds with the small batch requirements of pharmaceutical and biotech production. An alternative is batch campaigns, which can provide a viable middle ground that enables semi-continuous processing during scheduled production periods to limit energy waste.
Modelling new technologies based on whole-life costs is critical to supporting the business case. Using calculations to reduce typical cleanroom high air change rates, or computer simulations to create more sustainable buildings, these, together with early engagement with end users, model walk throughs and VR reviews reduce design time, and late changes on site. New ways to generate energy, with solar panels, cooling and heat pump chillers, coupled with innovative system designs reducing total energy requirements by thinking outside stereotypical systems. Also integrating the process design with mechanical and electrical engineering, utilising high precision valves in HVAC systems control airflows more accurately, and variable speed drives on pumps, thereby reducing energy waste. However, as engineers, we can only advise clients; to convince them there are cost savings to be made by converting from a capex focus to whole life costs, needs compelling evidence. Monitoring and measuring energy and water consumption is vital, so that opportunities to learn and improve can be analysed and implemented.
28 BUILDING SERVICES & ENVIRONMENTAL ENGINEER MARCH 2023 Read the latest at:
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