Life Cycle Assessment (LCA) based on ISO14040 (2006) is being increasingly adopted in architectural design and construction, as it CA enables decision-making processes, such as, evaluating and selecting environmentally-friendly products and optimizing construction processes.

In addition to assessing environmental impacts, LCA also facilitates estimating life cycle costs (LCC) and conducting life cycle energy analysis (LCEA). The incorporation of LCA into the building sector supports sustainable decision-making and promotes the evaluation of environmental, economic, and energy-related aspects throughout the life cycle of buildings.

It is noteworthy that energy efficiency has been a primary focus in the environmental design of buildings, with the use/operational phase playing a dominant role in the LCA of buildings, due to the high energy demand associated with building operation.

Operating energy, which includes energy for HVAC, domestic hot water, lighting, appliances, and building maintenance, is easily quantifiable and can account for up to 85% of total energy consumption and 70-90% of the environmental impact.

However, many of these factors are beyond the control of designers, particularly during the conceptual stage, as they are spread over the decades-long lifespan of a building.

Therefore, the selection of appropriate materials, which is often emphasized as a directive for energy-efficient design, becomes a critical decision factor in the design process. It is recommended to consider material selection as early as possible, as it not only impacts the operational energy performance of the building but also influences the total embodied energy and potential environmental impact.

From a life cycle perspective, the environmental impact and energy consumption of buildings are closely linked to the choice of materials. However, there is often a lack of alignment between the service life of materials (which determines the intervals for material renewal) and the service life of buildings (the duration of the operational phase). This can result in a trade-off between material selection and building energy demand and so, requires a holistic approach (Heeren et al., 2015) that considers the effects and trade-offs.

The after-use life cycle phase plays a significant role in determining the overall embodied energy of a building. LCA for the 'end of life' (EOL) evaluates the environmental impact, including the energy required for demolition, at the end of a building's service life, as this is vital for decision-making since it has the potential to substantially reduce the environmental impact of the building through effective after-use strategies, such as, disassembly, remanufacturing, biodegrade-ability and the 3R principles of reduce, reuse, and recycle.

Lupíšek, et al. (2015) innumerate the Design strategies for reduction of embodied energy and embodied carbon (Subtask 4 of Annex 57) in three steps: 1. Reduction of amount of needed materials throughout entire life cycle. 2. Substitution of traditional materials for alternatives with lower environmental impacts. 3. Reduction of construction stage impact.

A large number of building materials are reusable and recyclable, such as, Wood and untreated timber, and Earthen Materials (reusable/recyclable/biodegradable); Metals, mainly Steel, Aluminium, Iron, Copper, Masonry and Bricks, and Glass and ceramic (reusable/recyclable); Asphalt and Concrete (may be crushed and recycled); and Gypsum/Drywall (recyclable, sometimes biodegradable).

Recycling materials can contribute greatly towards reducing impact and can be achieved by; identifying materials in existing buildings that can be salvaged and reused in new construction projects, establishing on-site recycling programs, implementing comprehensive waste management plans, participating in material exchange networks, collaborating with local recycling centers.