Prolonged heat and unusually high water demand have prompted the Copper Sustainability Partnership to call for a longer-term approach to pipe-material selection across British buildings and water infrastructure.
Severn Trent recorded its highest single day of customer demand during July, exceeding peaks experienced during the 2022 drought and the Covid-19 period. South East Water has also reported sustained demand close to record levels, with temporary restrictions introduced across parts of Kent.
Utilities are responding to pressure across water abstraction, treatment, pumping, storage, leakage, and distribution capacity, while CuSP is focusing attention on the materials installed within buildings and infrastructure expected to remain in service through increasingly hot summers.
Founded by Lawton Tubes and Mueller Europe, which manufactures Wednesbury Tube products, the partnership brings together two competing copper-tube manufacturers to promote the material’s environmental and engineering characteristics.
Copper has a long record in plumbing, heating, cooling, refrigeration, fire systems, and industrial services. Its properties include high thermal conductivity, resistance to ultraviolet exposure, established joining methods, and the ability to be recycled repeatedly without deliberately converting the metal into a lower-grade product.
Plastic pipework has expanded across many applications because it can be lightweight, corrosion resistant, quick to install, and less expensive at the point of purchase. CuSP wants asset owners and designers to examine thermal movement, service conditions, maintenance, environmental performance, and replacement risk alongside initial material and labour cost.
“Too often, infrastructure decisions are driven by short-term considerations,” said Oliver Lawton, co-founder of the Copper Sustainability Partnership. “With climate pressures increasing, asset owners and developers should be focusing on lifetime performance, resilience and environmental impact. The materials selected today will still be in service decades from now, when hotter summers may be the norm rather than the exception.”
High water demand does not itself demonstrate that one pipe material is failing, and much of Britain’s supply challenge lies within reservoirs, abstraction, treatment capacity, leakage, pumping, and the limited ability to transfer water between regions. Material performance forms one part of a considerably larger infrastructure system.
Service conditions govern material choice
Temperature affects every pipe installation. Copper expands as it heats and contracts as it cools, requiring appropriate allowance within long straight runs, supports, joints, sleeves, and building penetrations. Plastic materials generally have higher rates of thermal expansion, placing greater emphasis on layout, clipping, expansion loops, and adherence to manufacturer limits.
Correctly specified plastic systems can operate safely across many water and building services. Performance depends on polymer type, pressure class, operating temperature, joint design, exposure, water chemistry, installation quality, and compliance with the relevant product and application standards.
Any material can fail when used beyond its design envelope. Excessive temperature, pressure cycling, unsupported movement, incompatible chemicals, poor joints, mechanical damage, or incorrect installation can shorten service life in copper, plastic, steel, and composite systems.
A hotter climate alters some of those boundary conditions because roof spaces, plant rooms, service voids, external enclosures, and exposed distribution routes can reach temperatures well above the surrounding air. Pipework may also experience wider cycles between daytime heat, night cooling, and intermittent water use.
Design calculations consequently need to account for the combined temperature of the water and its environment rather than relying on a nominal room condition. Supports, insulation, fire stopping, joints, and adjacent materials must accommodate movement without concentrating stress or restricting maintenance access.
Water chemistry introduces another variable. Copper, plastics, stainless steel, galvanised steel, and composite materials respond differently to hardness, acidity, disinfectants, stagnation, temperature, and flow. Selection must reflect the actual service rather than a generalised comparison between material families.
Whole-life assessment includes the consequence of failure as well as purchase price. Replacing a concealed pipe inside a hospital, apartment block, factory, or public building can require walls, ceilings, floors, or production areas to be opened, creating costs far beyond the value of the original material.
Conversely, a higher material price is not automatically justified where service conditions are moderate, access is straightforward, and an approved alternative offers suitable performance. Material selection remains an engineering decision balancing installation, durability, maintenance, carbon, recyclability, availability, and operational risk.
The Environment Agency’s National Framework for Water Resources estimates that England’s public water supply could face a shortfall of five billion litres per day by 2055 without additional action, while other parts of the economy may require a further one billion litres.
Closing that gap will require reservoirs, transfers, leakage reduction, metering, treatment capacity, demand management, and changes to industrial and domestic consumption. Dependable distribution and internal systems cannot create new water resources, but they can reduce avoidable loss and maintain service during periods of heavy demand.
“As industries invest further in the infrastructure that is built to last, we believe copper should play a central role in delivering systems that are robust, sustainable and fit for a hotter Britain,” Lawton said. “Futureproofing our water infrastructure will require a combination of copper materials, smart water management and essential collaboration between the plumbing industry, trade associations and public sector bodies.”
Climate resilience will require designers to use future operating conditions rather than historical averages when specifying complete systems. Copper will remain one of several available pipe materials, with its use determined by the temperature, chemistry, installation, access, expected life, and failure consequence associated with each application.
