Health Facilities Scotland publishes new operational guidance after review reveals 'performance gap' in design-stage modelling
The report explores why new healthcare buildings are failing in terms of energy efficiency
NHS estates professionals in Scotland are leading the way with the launch of a report into why new healthcare buildings are failing in terms of energy performance and carbon emissions.
Health Facilities Scotland, a division of NHS National Services Scotland, provides operational guidance to NHS Scotland health boards and recently commissioned a ground-breaking study into why some new-build medical centres suffer issues such as space overheating and high cold water temperatures, despite millions being spent on design and planning.
HFS is concerned that while the building designs and the design-stage modelling demonstrate the buildings comply with regulations and statutory overheating checks, there is evidence of a ‘performance gap’ between design predictions and actual building operation
The document, Engineering Evaluation of Generic New Build Health Buildings reveals the results of this research and what should be done across the NHS in Scotland, and in the wider UK, to ensure buildings deliver the expected outcomes in the future.
It states: “HFS is concerned that while the building designs and the design-stage modelling demonstrate the buildings comply with regulations and statutory overheating checks, there is evidence of a ‘performance gap’ between design predictions and actual building operation.
“These issues have attracted the additional costs of retrofit remedial measures being taken to address the problems.”
The research was undertaken by Mabbett and Associates and Integrated Environmental Solutions (IES) and explored the hypothesis that more-accurate data and deeper modelling at each design stage could identify and mitigate these problems before they occur.
And it makes a number of recommendations for improvements in the design and construction of future NHS buildings.
The findings were based on typical recent examples of both a health centre/clinic and a hospital ward.
Mabbett and Associates and IES investigated current energy use and thermal design within existing representative healthcare facilities in Scotland to provide realistic input data as the basis for more-accurate energy and thermal comfort modelling.
The modelling itself was performed by IES – developer and expert user of the IES Virtual Environment (IESVE)– a building simulation tool that is currently used in the design of energy-efficient, comfortable buildings worldwide.
IES Consulting performed baseline simulations using both the UK government-sourced National Calculation Method (NCM) data, which is used by designers for both design and compliance calculations in the absence of better data, and the more-representative data provided by Mabbett and Associates to highlight the implications of using real data earlier in the design process.
Further detailed analysis of various design factors also contributed to the final report which will be used to better inform design teams at the earliest stages of building projects.
Our new-build facilities were planned to be sustainable and healthy places to be in, but we were getting anecdotal feedback that in some areas they were not performing in the way we expected them to in terms of energy and thermal comfort
Speaking to BBH this week, Susan Grant, principal architect at HFS explains: “The NHS in Scotland, like everywhere else, is having to be more sustainable in the procurement of facilities.
“Our new-build facilities were planned to be sustainable and healthy places to be in, but we were getting anecdotal feedback that in some areas they were not performing in the way we expected them to in terms of energy and thermal comfort.
“We did investigations on this and found these issues were recurrent, consistent and persisted year round, not just in summer.
“We also looked at how we were briefing design teams and what might be causing the problem.
“We found lots of papers talking about the performance gap in new buildings and came to the conclusion that we were asking for the wrong things, but we didn’t know what they were or how to make improvements.”
NHS Scotland is unique in that all significant investments are put through the Scottish Capital Investment Manual (SCIM) process, which includes a ‘design assessment’ health check assuring they will meet their pre-agreed key outcomes.
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Grant said: “We scrutinise projects at key design review stages to see what they are achieving against the bespoke briefs that they set themselves at the outset, including NHS guidance and sustainability.
“But, as we had more and more anecdotal feedback, we started to question how this was put together and how health boards and their construction partners were proving they were meeting these briefs.
“What we discovered was outcomes are entirely reliant on an NCM model produced for compliance to building control regulations. But, if the assumptions on which this model are based are erroneous, then the outcomes will be as well.
“Whether we were looking at buildings in Orkney or Dumfries; we were finding similar issues. They were all reliant on modelling for key investment decisions. Yet we found models were based on bad assumptions, were not being developed early enough, and were not being challenged when outputs clearly deviated from reality.
“For example, the model stated one person/2sq m for a consulting room. At 16sq m, this assumption led to the demand air conditioning in outpatients wing due to eight people every day from 8am-6pm in every room.
“The model can do lots, but the issue seemed to be that what it can do is different to what it was doing and how they were using it.”
If we want to build buildings that work in terms of sustainability, energy use and thermal comfort, we need to get the right data
The team carried out a number of workshops and held discussions and, using the two example settings – an outpatient and an inpatient block – IES worked with ME specialists to go through the detail and work out what design decisions were being made, who was making them, and how they were affecting outcomes.
Grant said: “We considered real-life situations and started tweaking them where we are getting overheating outcomes.
“We then tweaked things in the model to see if we could change the outcomes.”
This has resulted in two new guidance documents. Part A is a summary aimed at client groups and designers which can be used for briefing, design and reviews on all future projects. This will enable better understanding of the implications of key assumptions when developing designs, allowing improved decision making and ensuring better-performing new facilities.
The second part is a larger and more-detailed technical document for M&E professionals and modellers.
Grant said: “It contains 10 recommendations for NHS building developers moving forward. We don’t expect people to use all 10 recommendations for every project, but they will probably use several of them.
“Ultimately, they will make the environments we invest in so much better and this will lead to savings.”
She added: “There are examples of where we are having to go into new buildings and retrofit air conditioning and chilling to water. This is not a sustainable solution. There is also a huge cost there.
“This new guidance will hopefully stop this from happening and lead to the creation of genuinely-sustainable buildings first time, every time.”
The NHS doesn’t really give designers the right details to build the right models at the moment. They have got to give the right data or they will be spending more and gaining less
David McEwan, consultancy director at IES, added: “It’s about looking at how we can be more analytical and make better decisions about the healthcare estate in the future.
“During our analysis we looked at a lot of the issues. We explored why cold water temperatures were too high and we discovered that the pipes often run through overheating ceiling voids and services risers. We also asked how window design could affect the problem with windows not being opened to relieve heat gain because of draughts.
“What we found was that some new buildings are overheating for thousands of hours – not just for short times.
“The work we carried out to explore the reasons for this identified a number of issues; most significantly it’s about the right type of analysis at the right stage in a project.
“The NHS doesn’t really give designers the right details to build the right models at the moment.
“They have got to give access to the right data or they will be spending more and gaining less.
“If we want to build buildings that work in terms of sustainability, energy use and thermal comfort, we need to get the data right.”
The new document, with its recommendations, is now available on the IES website and it is anticipated that it will be used by health trusts across the UK moving forward.