The UK climate is changing. More frequent flooding events, periods of high summer temperatures, colder winter conditions and increased storm intensity are placing growing demands on the built environment. While these pressures remain moderate compared with some global regions, they present clear challenges for buildings expected to deliver consistent performance over long design lives.
For architects, developers, specifiers and planning authorities, climate resilience is no longer a peripheral consideration. The ability of external wall materials to withstand environmental stress, maintain performance and recover from extreme events is central to long-term durability, asset value and risk management.
Clay brick has a long and well-documented history within the UK built environment. Its performance under heat, moisture and mechanical stress is well understood, supported by centuries of use and decades of formal testing. Crucially, this performance is derived from it’s inherent material properties, not from applied coatings, membranes or surface treatments that may deteriorate over time.
Material Behaviour and Climate Resilience
Clay brick is crafted from natural materials, clay, water, and sand, and fired at high temperatures under controlled conditions, producing a dense, vitrified ceramic with a stable microstructure that balances strength and controlled porosity. Unlike non-porous materials that can trap moisture, clay brick is vapour permeable. This "breathability" allows the building fabric to manage moisture effectively, facilitating the passage of water vapour and reducing the risk of interstitial condensation, a vital factor for both occupant health and structural longevity.
UK manufacturers test bricks rigorously against British Standards (BS EN 771-1) for compressive strength, water absorption, and freeze–thaw resistance. The engineered pore structure helps regulate moisture uptake without compromising durability; by allowing moisture to move and evaporate naturally, units resist the internal pressure of ice expansion, preventing frost damage and spalling during sub-zero cycling.
These intrinsic properties, water resistance, mechanical robustness, and thermal stability mean that clay bricks do not rot, corrode, or chemically degrade under UV exposure or atmospheric pollutants. This predictable performance, verified through UK testing, gives designers confidence in clay brick as a durable, resilient choice for a changing climate.
Performance in Key Weather Conditions
Heat, Cold and Seasonal Temperature Extremes
More pronounced seasonal temperature swings, including hotter summers, more frequent heatwaves and periods of sub-zero winter temperatures are placing increasing demands on building fabric. In both urban and high-density developments, managing internal comfort across the full year is becoming a critical design consideration.
Clay brick is a heavyweight material with high thermal mass, enabling it to absorb and store heat energy and release it gradually over time. During summer conditions, this helps moderate daytime heat gains and reduce peak internal temperatures as external temperatures fall. In colder periods, thermal mass can help stabilise internal conditions by retaining heat and reducing the impact of external temperature drops.
When incorporated into an appropriate building design, thermal mass can significantly moderate internal temperature fluctuations. Research from the Building Research Establishment (BRE) indicates that heavyweight construction can reduce peak internal temperatures by several degrees compared with lightweight alternatives, while also contributing to more stable internal conditions during colder weather.
This year-round performance supports passive design strategies that limit reliance on mechanical heating and cooling systems, improving energy efficiency and occupant comfort in both residential and non-residential buildings.
Flooding and Water Exposure
Flooding is affecting an increasing number of sites across the UK, making material selection and long-term resilience critical considerations. Fired clay brick retains its structural strength even when saturated, and it does not soften, swell, or delaminate under prolonged water exposure.
Clay bricks undergo rigorous testing to ensure performance in challenging weather conditions. Water absorption tests assess their ability to cope with moisture, while compressive strength tests verify their suitability for structural loads. Dimensions are carefully measured to meet British Standards (BS EN 771‑1), ensuring consistent quality and fit.
Durability testing also includes freeze-thaw cycles, simulating harsh winter conditions, and checks for efflorescence, the powdery mineral deposits that can affect aesthetics. Colour consistency is scrutinised to guarantee long-term visual appeal.
Following flood events, masonry walls built from clay brick can often be cleaned, dried, and reused rather than replaced, reducing remedial work, minimising material waste, and supporting faster reinstatement of buildings.
The ability to recover after water exposure is increasingly recognised as a key factor when specifying materials for flood-prone locations, reinforcing clay brick’s reputation as a resilient, long-lasting solution.
Storms, Wind and Impact
More intense storm events increase exposure to wind-driven rain and debris impact. Clay brick offers high compressive strength and strong resistance to mechanical damage.
When correctly detailed and constructed, brickwork forms a robust external envelope capable of withstanding severe weather conditions with minimal maintenance. This robustness is particularly relevant for large-scale housing, education and public-sector developments where long-term performance, durability and whole-life value are critical.
Specification and Planning Considerations
Clay bricks manufactured by members of the Brick Development Association are produced in accordance with UK and European standards. Products are tested for compressive strength, durability, frost resistance and water absorption.
For specifiers, architects and planning authorities, this provides confidence that brickwork can be selected to suit local exposure conditions, durability designations and long-term performance requirements. The availability of well-established standards and guidance supports informed specification and consistent outcomes across a wide range of project types.
Designing for a Changing Climate
Climate resilience is fundamentally about understanding how materials behave over time under repeated environmental stress. Clay brick offers established, predictable and well‑documented performance across the weather conditions most relevant to the UK climate, supported by rigorous testing against British and European standards for compressive strength, water absorption and freeze–thaw resistance.
However, resilient performance depends on selecting the right brick product for the specific exposure and application. Clay bricks are classified by durability and frost resistance to match site conditions, from moderate exposure to severely exposed external walls, and designers should align product choice with exposure risk, moisture conditions and detailing requirements.
For those responsible for delivering buildings that must perform reliably for decades, clay brick remains a proven and dependable external wall material. By choosing products suited to the anticipated environment and application and referencing best‑practice guidance such as the BDA’s range of technical guides, you can support resilient, durable and adaptable development in a changing climate.
Download the BDA technical guides here: https://www.brick.org.uk/guides BDA
