On a global scale resident and commercial buildings are responsible for approximately 25% of CO2 emissions each year. According to a government audit of emissions, hospitals are one of the worst offenders for carbon emissions, with building energy use cited as the second largest contributing factor after procurement. Looking at secondary health care, specifically acute care, we find building energy is the primary cause of emissions.
Insulation and thermal efficiency
Poor insulation plays a significant factor in a building’s heat loss and condensation in winter, and is responsible for most of the heat gain in summer. Ensuring buildings have energy-saving features plays a vital role in reducing carbon emissions, with exterior cladding playing a contributing factor.
Thermal insulation applied to a building’s external structure eliminates the thermal bridges, reducing temperature fluctuations inside the building which in some cases can lead to energy savings of up to 40%. These savings can then be reinvested into better facilities and patient care.
Providing insulation to an existing building through exterior cladding is significantly easier than undertaking steps to add insulation to the internal walls. When Altiplan° architects undertook the facade refurbishment of Clinique Saint Jean, Belgium, the hospital’s original build featured an energy inefficient stone facade. The most effective solution was to replace the facade with exterior panels on a fixed system that allowed for the addition of thermal insulation. A further advantage of external insulation, unlike in the case of internal insulation, is the fact that it avoids reducing valuable internal habitable space.
Exterior cladding in combination with a depth of insulation between the cladding and the wall not only minimises thermal bridging but also offers an acoustic advantage.
From a healthcare perspective, improving the acoustic performance of a hospital building means patients and occupants are less likely to hear noises from outside. The World Health Organisation (WHO) estimates at least 1 million healthy life years are lost each year in Western Europe due to health effects arising from noise exposure to road traffic alone.
Although the facades used for Clinique Saint Jean were not specified explicitly for their noise cancelling properties, given that the ventilated facade system is composed of different layers, there is an increase in the level of noise absorption taken by the different elements. When it is considered that the hospital incorporates parking facilities and is located on the corner of a major traffic artery, the acoustic advantage cannot be dismissed.
Weather resistance and air pollution
For many architects, it is imperative that the selected panelling is made from surfacing material that can withstand the natural elements and is complemented by a fixing system to support ventilated properties.
Man-made materials that are 100% natural, such as sintered compact surfaces, provide facades with inherent solar protection and, via the correct fixing system, water impermeability; essential qualities in preserving the facades and ensuring cost effectiveness in terms of maintenance.
Air pollution can directly affect buildings and structures, from exhaust fumes causing staining, to acid rain gradually breaking down the surface area of facades. In addition, freezing temperatures and wet weather can cause the surface water on a building facade to freeze, with the frequent expansion and contraction of the water resulting in surface cracks and structural weaknesses. As a result, stain resistant facade options made from waterproof materials, with some offering as little as 0.08% porosity, are often favoured by architects.
Near-zero porosity also means surfaces that are graffiti resistant; this in combination with a facade material that has inherent UV resistance provides exterior cladding where colours do not fade after being exposed to sunlight, which in turn has aesthetic advantages.
Colours are shown to have a psychological and physiological effect on the individual which is why the aesthetic of a healthcare environment is relevant since it can impact on patient wellbeing. Exterior cladding with design options to produce colourful or iridescent facades challenges the dull and drab appearance associated with conventional hospitals, making them more welcoming.
An example of a hospital exterior challenging convention design can be seen in ZOL Campus St-Jan in Genk, Belgium. The hospital had updated its global care strategy and wanted this echoed in the building of its new wing; leading architect on the project, Gunther Herrijgers from Architectengroep A4, envisioned the hospital building to have an abundance of clean lines and seamless aesthetic. To accomplish this, StrongFix, a unique comprehensive fixing system developed by TheSize specifically for architects, was specified so that 6mm Neolith exterior facade panels could be installed.
The utilisation of the only fixing solution on the market for 6mm panels meant the convenience of being able to hang the exterior facade panels to the support structure without the fixations being on display, thereby enhancing aesthetic. Further advantages of the fixing system include the simplicity and speed of the installation process, as well as the ease of access provided to electrical systems.
In terms of practicality, lightweight panels are often favoured since they promote efficiency during builds by reducing the structural load and are cost effective should the building require any future renovations. This is especially significant in the healthcare sector where budget increases for building projects are unlikely to be granted.
Many exterior cladding panels can be added to existing facades, which in combination with lightweight properties, means building improvements can be undertaken without the installation being disruptive to occupants. For environments such as hospitals, where patient care takes priority and decorum is essential to achieving patient wellbeing, this is particularly beneficial.
Exterior cladding has a significant role to play in architectural design and energy efficiency regardless whether it is applied as a reactive measure in support of carbon emission reduction or as part of the fundamental design plan for the next generation of energy efficient hospitals. Used carefully, facades can turn old buildings into architectural masterpieces. More importantly, exterior cladding, when specified correctly, offers hospitals greater energy efficiency and cost savings, meaning there is greater potential to invest back into patient care.