Addressing climate change requires us to become more aware of and more concerned about the impact of our actions and choices both as individuals and as a society. In the pursuit of re-evaluating our impact, methodologies such as Life Cycle Assessment (LCA) have grown in popularity in the recent years as they help us make informed decisions. But what is LCA exactly?
Simply put, LCA answers the question “What is the environmental impact of this object?” LCA provides a framework within which to assess the environmental impacts of a product or a service from a “cradle to grave” perspective. This means LCA considers every aspect—from the extraction of raw materials until the product’s final disposal—considering factors such as which raw materials are used, how much water is consumed, how the material is transported and what the transportation distance is.
Why do we need to focus on the building sector and how can LCA help with that?
With buildings’ share of the total energy demand reaching 40% and their generated CO2 emissions contributing to 36% of the total emissions in the EU, there is no question that buildings play a critical role in the energy transition and the fight against climate change1. For us to make a difference, we need to get a deeper understanding of where the impacts come from and how different choices can help us reduce them.
LCA is a tool that can help us understand the environmental impacts of buildings so, in turn, we can design more sustainable and energy efficient buildings in the future. By using LCA on buildings, we can learn how a building will affect the environment throughout its existence – from the extraction of its raw materials to its final demolition and disposal.
What does a building’s life cycle look like?
The typical life cycle for a building includes the stages described on the image below. These are according to EN 15978:2011 ”Sustainability of construction works. Assessment of environmental performance of buildings. Calculation method”.
- Product Stage – The product stage includes all the processes related to the impacts that building materials have until the factory gate. This refers to the impacts from the extraction of raw materials and their transport to the factory, and the impacts from the manufacturing of the final construction product.
- Construction process stage – The construction process stage includes impacts from the factory gate of the different construction products to the practical completion of the construction work;
- Use Stage – The use stage refers to impacts from the operation of the building – the impacts of the use, refurbishment, repair, maintenance of construction products and services and most importantly, the energy and water consumed during the building’s lifetime.
- End of life stage - This includes the impacts from the demolition of the building, the transport of the waste to the final destination of their disposal, their processing in the waste facility and their final disposal;
- Benefits and loads beyond the system boundary - This segment communicates all the potential impacts and benefits from the reuse, recycling and recovery of materials at the end of their life time. This segment does not belong to the lifecycle of the building but consists of information that it is important to know.