As part of meeting our commitments to reduce emissions to net zero by 2050, Chris Miles of Kingspan Facades looks at the options for specifiers when it comes to holistic approaches to maximising thermal efficiency in facades
In June, the UK became the first major economy to pass laws to achieve net-zero emissions by 2050. Improving the energy efficiency of buildings has been identified as “a key pillar of any credible strategy” to meet this ambitious yet vital goal, as well as “one of the cheapest” and most practical ways to do it. It is clear that over the next 30 years the industry must rapidly change and adapt its methods of construction, and deep discussions are already happening in the architectural community on the best materials and approaches to do this. With approximately 19 per cent of the UK’s total emissions attributable to heating buildings, the building envelope is a logical place to start.
Through-wall facade systems are a popular choice for many buildings in all kinds of sectors. From simple, single-component insulated panels to multi-layered built-up designs; they offer a holistic solution which enables high levels of thermal efficiency to be met, without compromising on other performance aspects such as fire, acoustics, environmental impact and weathertightness.
A built-up system offers the widest range of design potential. As all the elements are separately installed, it allows different combinations of insulation and rainscreen finishes to be selected to suit each project. However, considerable attention must be paid to detailing to ensure all the components are installed together to achieve the designed airtightness, insulation continuity and to minimise thermal bridging.
Meanwhile, while there may be less variety with panelised systems, their singular, factory-engineered construction simplifies detailing, providing greater assurance of reliable levels of insulation and airtightness. Available in an array of profiles and colours, they can also reduce the length and complexity of the construction programme, limiting on-site adjustments and waste.
A good compromise is a facade construction which uses insulated panels to provide weathertightness and thermal performance, and an external support structure for the preferred cladding. This enables buildings to be made as energy efficient as possible and weatherproof at an earlier stage than with a conventional built-up system, while retaining greater design freedom.
Just as there are different advantages to using different systems, component materials also require careful consideration. For example, while mineral fibre can be more suitable for buildings where reducing external noise is a requirement, rigid thermoset insulation has a much lower thermal conductivity, allowing high levels of thermal performance to be achieved with a slimmer build up. This not only creates more useable space but is also proven to increase daylight levels penetrating through windows. As well as improving occupant wellbeing, it may help to reduce a building’s artificial light demand.
It is also important to think beyond energy efficient design to the sustainability of the materials themselves. Manufacturers are increasingly looking to minimise the impact of their products through maximising the use of recycled content and improving the efficiency of their processes. Many modern panelised systems are also designed to be easily disassembled at end of life and then recycled or reused.
What already exists
With an estimated 80 per cent of the buildings that we will occupy in 2050 already built, and only 15 per cent of those constructed after the introduction of insulation and energy performance standards in 1990, the refurbishment of existing stock will be critical to meeting the decarbonisation goals.
Where the original structure is sound, through-wall facade systems offer a simple retrofit solution that can be a much more cost- and time-efficient solution than demolishing and rebuilding. They enable both the energy efficiency and overall look of a building to be transformed, maximising the return on investment on the original structure whilst also eliminating carbon emissions from the demolishment process and reducing waste to landfill – all helping to reduce the environmental impact of the project.
Enveloping the issue
There are many aspects for the architectural industry to consider as the UK moves forward on its climate commitments and it will be interesting to hear the discussions and solutions coming out of forums like the new Facades Academy at the Building Centre in London. Whatever transpires, flexible and high-performance solutions, such as through-wall facade systems, will be crucial to creating buildings which are ready to meet a plethora of demands, both now and in the future.
Chris Miles is regional sales manager at Kingspan Facades