Copper facades, roofs and other external architectural elements develop a protective patina over time which can reform if damaged. This ensures extreme durability and resistance to corrosion in virtually any atmospheric conditions and, unlike some other architectural metals, copper does not suffer from underside corrosion. Consequently, it is invariably the supporting substrate or structure that eventually fails rather than the copper itself. In fact, copper roofs have been known to perform well for over 700 years.
Copper is generally applied as a lightweight covering, requiring less supporting structure than many materials. With a low thermal expansion value, movements due to temperature changes are minimised and designed-for, avoiding deterioration and failure. In addition, the high melting point of copper ensures that it will not ‘creep’ or stretch as some other metals do. Copper is also classified as A1 (non-combustible material) in accordance with EN 13501-1:2007+A1:2009.
It is safe to use and can be worked at any temperature, without becoming brittle in cold weather or deforming in hot weather. It requires no decoration, maintenance or cleaning, saving resources, cleaning chemicals and cost. Copper sheets’ (copper massive) interaction with the environment has been assessed under the European Reach chemical policy and has no classification/restriction.
Production and Recycling
European copper products for architectural applications are produced to EN 1172 specifications in world class plants with strictly monitored environmental performance and well-established recycling routes. They include high levels of recycled materials – typically 85% or more with scope up to 100%, saving on energy and greenhouse gases, and contributing to the circular economy.
Copper occurs naturally as part of the cycle of metals which form in nature, being used by society and returning to nature or being recycled for further use by society. The economic value of copper drives recovery and recycling, not just of copper but also many other materials during dismantling and demolition.
The recycling of copper is a well-established practice and its extent follows overall consumption patterns. This is due to the relative ease, compared with other metals, of re-using both processing waste and salvaged scrap from eventual demolition, as well as the incentive of copper’s value. Copper can be recycled again and again without any loss of performance or qualities.
The copper industry – from mining to fabrication – spends in the region of 30% of capital expenditure on improving environmental performance. The processing of copper is on a ‘Continuous Improvement Program’ to service customers and shareholders, and comply with current market and policy needs. The industry is responding to the European Commission ‘circular economy’ initiative and looks forward to receiving more scrap for re-use as the economy becomes more efficient at managing material use throughout its life, especially towards end-of-life.
Environmental rating tools are important for investment decisions and useful for looking at the whole supply chain and determining where the greatest improvements in environmental performance can be made for a given product. Unfortunately, they have many inadequacies when used to make comparisons. For comparisons to be worthwhile, accuracy of the tool and the methodology behind it need to be both robust and fair when comparing two products of very different compositions and implementations, even if for the same use.
For simplification, too many tools have used non-robust and unfair assumptions, resulting in extremely misleading comparisons. Easy mistakes to make include:
- comparing energy and cost per tonne rather than per m2 of material, thus misrepresenting thinner, lighter materials such as copper
- missing the cost and environmental benefits for complete construction of lightweight materials
- using inappropriate life span estimates, thus adding ‘energy use’ for unnecessary replacement
- disregarding today’s efficient recycling practices.
Today, we urge architects to focus their comparisons on: Primary Energy; Ozone depletion potential; Acidification potential; Eutrophication potential; and Photochemical Ozone Creation potential. These are impact categories that are well-known, global and mature – rather than other lesser known, non-robust and erroneous comparative indicators, especially in the field of toxicity, land use and resource use.