As an important part of the building structure, facade design and specification can make a significant difference to embedded and operational carbon. However, there are several important steps that can be taken to minimize the impact.
Recycled and recyclable materials
To create a sustainable design, it is important to consider the entire life cycle of a material – including the extent to which it can be recycled at the end of its life and how much energy is needed to recycle it. Choosing products that are themselves made from recycled materials is also an important consideration. This minimizes the amount of waste, reduces the demand for ‘primary’ materials and reduces the embedded carbon in the system and thus the building.
From this point of view, aluminum has a number of important advantages. It is infinitely reusable without loss of quality. It is also easy to separate from other waste, so that a large part of the aluminum components at the end of the life of the building can be recovered and reused.
In addition, smelting recovered aluminum for recycling requires only 5% of the energy required to produce primary aluminum. This means that recycled aluminum products have a much smaller CO2 footprint.
Hydro CIRCAL® 75R aluminium
At SAPA, more and more door, window and curtain wall products in the portfolio are made from Hydro CIRCAL® 75R aluminium. This high-quality aluminum contains at least 75% recycled aluminum at the end of its life cycle (post-consumer scrap), from, for example, facades and windows removed from buildings.
As a result, it has one of the smallest CO2 footprints of all aluminum in the world, with 2.3 kg of CO2 emissions per kilos of aluminium. This is 86% or 7 times less than the global average for primary extraction.
Another important part of improving the sustainability of the building is the reduction of the energy required when it is in use. A ‘substance first’ approach is central to this and is increasingly becoming a focus of building design in all sectors. By optimizing the performance of the systems and products that make up the building, the required amount of heating, cooling and lighting can be reduced. The correct specification of facade systems, including doors, windows and curtain walls, can minimize thermal bridges and maximize airtightness, while helping to maximize natural light and prevent overheating.
prevent heat loss
Facade elements designed for excellent thermal performance have a high level of insulation and thermal breaks in the structure to prevent heat loss. For example, the modern and sleek design of SAPA’s C160 and C160S doors includes fiberglass-reinforced polyamide strips that reduce heat conduction, with the option to add thermal inserts to further improve performance. As a result, the C160S can achieve a frame U-value (Uf) of only 1.40 W/m²K.
However, when choosing products and systems, it is important to ensure that in practice they will perform as designed, as ‘performance gaps’ can seriously affect a building’s operational emissions over its lifetime. Therefore, architects must ensure that all specified products are thoroughly tested. SAPA has invested in state-of-the-art test facilities to provide the necessary test data, as well as project-specific support for more complex requirements.
In addition, the design can be optimized by working with a system specialist so that it provides the best possible levels of natural light without affecting the comfort of the building’s users. This may mean that shading elements should be designed and positioned to shield certain heights of the building from the peak summer sun without blocking daylight from the winter sun at a lower angle.