The health sector has always had a lot of documentation to influence design and use, so how is the energy agenda influencing buildings? David Rowley, Malcolm Stroud and Milorad Vucinic of Nightingale Associates reveal how it affects their designs

Both energy and sustainability are major design factors in health building procurement. The situation is not simple because many of the drivers for change in health also have an impact on energy. There are many changes coming, not just from new performance-based regulations and codes, but increasingly from developing attitudes and values. Change is likely to lead to real commercial pressures in the PFI process. Many tight urban sites could soon be unsuitable for developing environmentally compliant buildings at the current expected densities.

Health has always been highly structured in terms of regulation, guidance and codes of practice. There is a vast suite of NHS documentation issued through the Department of Health’s estates and facilities division. Building Regulations and planning requirements still apply of course, but before the arrival of Part L 2006 the focus of effort has been mainly on the NHS requirements. While energy and sustainability are important, the NHS also has other major agendas that impact on sustainability design. The increasing regulatory environment makes the process of compliance far more complex.

Evidence-based design

Health design is moving to a more evidence-based approach, based on factors that influence patient and operational outcomes and that help people get better more quickly. In general, happy buildings – those that work for patients and staff – are often more important to clients than energy cost but there are synergies between these.

There is increasing recognition of the importance of daylight, good natural views, good acoustics, infection control, safety, reducing stressors and ensuring patients are able to get a good night’s sleep, as well as more consideration of staff travel times on wards. For instance, improvements in views from windows and additional sunlight can improve patient well-being and recovery times. So if hospital windows are designed to provide better daylight, they may also lose more heat in winter and allow in more summer heat, but if such measures reduce patient stays, it may be possible to operate with fewer rooms, thereby saving in energy. This is a real balancing act.

One of the current trends in hospitals is towards more single rooms. This has a number of advantages, such as flexibility of use, improved acoustics and greater infection control.

Part L 2006

At Nightingale Associates, we appreciate the changes to Part L as they are logical in their approach to reducing CO2 emissions and because they allow for flexible solutions. However, the changes have also brought confusion: for instance, it may prove to be more cost-effective to improve a hospital’s boiler than to spend more on the glass. The cost impact of each elemental improvement needs to be assessed if money is not to be wasted. As a result there will need to be much more intellectual effort and time invested to get a project off the ground in a way that best satisfies Part L as well as the other sustainability and design issues that are specific to the sector. Clients are going to have to commit more time to the very early stages to ensure viability: the alternative is to guess and overprice.

At Nightingale Associates, we appreciate the changes to Part L as they are logical in their approach to reducing CO2 emissions

PPS 22 and renewables

PPS 22 requires the on-site provision of renewable energy sources, first promoted by Merton council, and has to be considered alongside Part L. Each local authority has a different requirement for renewable energy provision, ranging from 10-20% of energy use. Part L provides a flexible robust process for encouraging the equivalent of up to 10% so it could be extended to give a more robust system. There are planning issues beyond the individual site and some inner city sites may be blighted. We are currently looking at CHP and borehole cooling for some city centre sites, but not all sites are suitable.

Conflicts in design criteria

Environmental performance is a significant constraint on design. Very often hospital design requirements favour a deep plan but natural ventilation, good daylighting and views demands a shallow one. Fire control and ventilation can also be at odds: it may not be possible to naturally ventilate a deep plan building with atriums.

To tackle these issues, new combined solutions including fire engineering are needed to make deep plan buildings work. There is also a need to consider design issues such as restricted window opening to prevent suicide risk and look at more flexible window designs and services that allow for maximising natural vent where and when possible in conjunction with assessment of the actual managed risks.

To make buildings last longer there is also a real need for flexibility to be designed in – for future extensions, adaptations, change of room use and downsizing. Narrow or shallow planned buildings are more flexible, while deep planned buildings may need to be opened up later.

Issues that also need to be considered are:

  • Prefabricated and off-site construction: some of this will need to be rethought to incorporate thermal mass.
  • Climate change: increasing temperatures mean greater use of solar shading, thermal mass allowance for plant /duct space, more mixed mode and more water reduction and re-use.
  • PFI fuel purchase arrangements: there is little financial incentive to invest in energy saving in health PFIs as those who finance and build the building are not usually responsible for buying the energy to run it so the loop is not properly closed.
  • Restricted sites: in some cases there is a need to challenge sites’ suitability to achieve some briefs in a satisfactory manner, particularly if deep plan is the only option.
  • Changes to care model strategies: these are driven by the government and trusts, and could lead to the increasing use of local centres for treatment rather than larger acute hospitals.
  • Procurement factors: the PFI process tends to just meet the brief and satisfy the legislation and codes in the cheapest way. It has nothing in-built to drive energy and sustainability incentives above these. The trust’s payback is about five years, which is not a long enough period to reclaim energy efficiency investments. The benefits of improvements could be identified but clients need to ask for these to be identified as additional cost options to reduce their running costs.
  • Design and sustainability: one of the keys to good design is how it is worked up in the sections. NEAT (see “Key documents”, right) needs to be used properly.
  • Auditing and enforcement: NEAT and BREEAM (right) are initially design-stage tools to highlight and assist many sustainability choices. It is possible to get an excellent score on paper but the as-built result can be lower if energy-saving features are value-engineered out so more independent checks are required to help ensure compliance with the final building. BREEAM and NEAT need to be updated together to reduce confusion and may soon require third-party assessment.