Sustainability needs to encompass long-term durability factors in addition to embodied energy to provide an accurate picture. Keith Aldis of BDA (Brick Development Association) explains how achieving this bolsters the eco case for brick
When considering the materials that may be used in a building’s exterior envelope – one of the most critical elements for a structure overall – the cost effectiveness of each component and option is generally scrutinised, often over a relatively short time frame rather than for an extended building life expectancy. Through this simplified decision-making process there are often occasions where an individual component’s actual life cycle is miscalculated, or incorrectly reflected.
Durability and longevity of the various material components can dramatically influence the sustainability of projects. The correct use of a material can extend a building’s life, protect its other components, and be flexibly repurposed. To truly reflect the sustainability credentials of a building’s envelope or an entire project, these factors would need to be considered, especially with products making up a significant portion of the structure. As the discussion around a circular economy grows and adapts it can seem difficult to achieve a true and fair comparison of potential material options. This is especially true when comparing new materials on the market that come with great sustainability credentials but have not yet been tested for durability or longevity. In addition to being an iconic part of our built environment’s architectural history, traditional building materials have stood the test of time and can now offer us certainty as we navigate our way through how we look at the circular economy.
If you take a look at the components used in many of the UK’s historic buildings and high streets, it is clear that brick has a track record of not only lasting a very long time but ageing beautifully as well. A well designed and constructed brick building has a typical lifespan of 150 years or more. Currently, materials are certified under the assumption that all material components will have a lifespan not exceeding 60 years.
Brick’s track-record offers certainty that the material will exceed this lifespan, which is important because even with the most efficient and sustainable processes and testing in place, all materials need to stand the test of time. When a completed home or development is made with materials or a mix of the wrong components it will require significant maintenance or may be demolished all together, a process that is wasteful, expensive and not sustainable when looking into the longer term.
Where materials come from and the distance they travel to a building site or through their own production is also an important aspect when looking at building more sustainably. For example, clay brick is produced in ample quantities across the UK at over 56 locations to satisfy the growing demand for new quality-built homes and buildings. Using locally sourced products made in the UK significantly reduces transport costs and the carbon emissions involved in the delivery of these products. On average clay brick produced in the UK only travels 67 miles from production to building site. When comparing transport costs and emissions to alternative materials, that often include multiple components which are shipped across the globe in the process, locally produced sustainable building materials are instead available.
Adaptability & resilience
A material’s adaptability and resilience contribute to its sustainability in a similar way. Attributing sustainable credentials to developments based on the ability to easily deconstruct them and send its various used components through laborious recycling processes is flawed. Unfortunately, as a society we have not come far enough to make many of these processes viable. We are slowly beginning to challenge these processes, but they will not be fixed or easily replaced with more viable options. The follow-on impact of transporting components and the process of reconstruction on overall sustainability is extraordinary.
The resilience of clay brick can ensure that a building can withstand the wear and tear of multiple occupiers, and through intelligent design, and brick’s natural flexibility as a building material, these buildings can be easily adapted for multiple uses over decades or even centuries. Coupled with the sustainable process of locally sourcing material and a short supply chain in the manufacturing process, clay brick continues to be a sustainable option as it produces aesthetically pleasing homes that are enjoyed for generations.
One of the areas that we in the construction industry will continue to focus on is the longevity of the housing stock being approved and promoted by the UK government. Recent discussions and campaign pledges on new homes have been focused on the need for volume and speed, but on their own these elements won’t address the issue of available, affordable housing long-term; if the longevity of the housing isn’t prioritised, we will continue in a cycle of requiring heavy maintenance and the demolition of poorly built homes and buildings in our communities within a lifespan of less than 60 years.
Naturally, brick has a high thermal mass giving it the ability to absorb, store and release heat energy. Thermal mass can be used to even-out variations in internal and external conditions, absorbing heat as temperatures rise in the day and releasing it as they fall which makes for a more comfortable atmosphere which is naturally regulated, reducing the need to mechanically heat and cool a building.
The need for sustainable products comes from a growing population who will always need somewhere to live and work. The push for so-called ‘modern’ materials and fast construction risks undermining this unless quality is insisted upon. Perhaps this is why recent ONS stats show that UK brick producers have sustained a consistent rise in deliveries for new developments in the past 12 months, as the focus of a circular economy grows and a building’s longevity and future flexibility is considered alongside each of its individual material components.
Keith Aldis is chief executive at the Brick Development Association