Energy efficiency: the best solutions for buildings
Energy conservation is one of the main challenges in many sectors and is a big issue in many government policies. It also concerns the construction industry: let’s discover what buildings’ energy efficiency is, how to achieve it, and how envelopes play an important role.
What is the energy efficiency of a building?
Building energy efficiency means using less energy in a building so that there is less waste and the building works well. It includes designing, building, and using technology to keep the structure comfortable, useful, and productive.
Thermal performance and renewable energy sources are just two elements of buildings’ energy efficiency.
- Insulation and thermal performance. Insulation keeps the heat inside during cold times and outside during hot seasons. Good windows, doors, and roof materials help keep the building’s temperature right without needing heaters or air conditioners too much.
- Good heating, cooling, and air systems. These systems (HVAC) help control the temperature inside. They work better when they request less energy. Some ways to do this are using smart thermostats, energy recovery ventilators, and other equipment to regulate indoor climate with minimal energy consumption.
- Renewable energy. It means relying on natural energy sources like the sun, wind, or heat from the ground to power the building. When buildings make their own clean energy, they do not need to rely as much on regular electricity.
- Smart technology. Smart technology includes machines and systems that can keep track of how much energy is being used and change settings to waste less when it is possible. For example, lights that turn off when nobody is in the room or systems that adjust how much heating or cooling is needed based on the time of day and how many people are there.
- Smart building design. Designing is another pivotal element. Thanks to modern and sustainable approaches, buildings are designed so that they let in natural light, keep out too much heat from the sun, and let air flow easily without lots of fans or air conditioners to help save energy.
What is building energy efficiency rating?
Buildings like houses and offices use up a lot of energy. In fact, they are responsible for more than a third of all the energy we use globally. Furthermore, the global floor area is experiencing rapid expansion, particularly in developing nations. For this reason, the amount of energy used keeps going up.
It is evident that the buildings we construct play a pivotal role in shaping our energy future. With this understanding, it becomes imperative for stakeholders to prioritise energy-efficient design and sustainable practices. By doing so, we can mitigate the environmental impact of the buildings sector and pave the way for a more sustainable future.
Governments and international organisations such as the European Union have therefore introduced an energy rating system for buildings.
The aim is to have a certification regarding the energy consumption of individual buildings and to indicate which ones are better and which ones require improvement interventions. The rating also contributes to the economic evaluation of a building.
The classification follows a fairly standard scale, ranging from class A to class F or G, depending on national and local regulations.
- Class A identifies buildings with excellent energy efficiency. This means they use minimal energy resources to provide the required service, such as heating.
- As you go down from class D, buildings require more energy resources and the desired outcome is not necessarily achieved. These buildings are indeed sources of energy waste, making it crucial to address them with various types of interventions.
The interventions include:
- installing new heating and cooling systems;
- taking actions on the building envelope to enhance ventilation and energy consumption.
In the case of external renovations, thermal insulation, wall claddings and other interventions on the facades can be considered after careful analysis.
Which building material is more energy efficient?
The high energy class of a newly constructed building does not solely depend on the efficiency of heating, cooling, lighting, and electrical systems. The material used for constructing load-bearing structures and facades is becoming increasingly important, especially when considering innovations in the sector.
There are innovative solutions such as bio-bricks, straw insulation panels, sheep wool insulation, carbon concrete, and composite metal foams. At the same time, among the most energy-efficient building materials is recycled steel, which retains all its fundamental characteristics.
Recycled steel is considered energy-efficient for a few reasons.
- Saving energy. When we make steel from recycled scrap, it takes way less energy than making it from scratch with raw materials. This means we use less energy overall when we produce steel this way.
- Cutting emissions. Recycling steel creates fewer greenhouse gas emissions compared to the usual way. This helps lessen the environmental impact of making steel and reduces our carbon footprint.
- Preserving resources. By recycling steel, we do not need to dig up as much iron ore and coal. This saves natural resources and lessens the environmental harm caused by mining and extracting these materials.
- Less waste. Using recycled steel means we do not throw away as much stuff into landfills. This is good for the environment because it helps us manage waste better and reduces the need for new landfills.
What are the materials used in energy efficient facades?
Energy efficient facades provide many solutions with a positive impact on buildings.
- They allow daylight into a building.
- They prevent unwanted solar heat from entering the structure.
- They also store heat within the mass of the wall.
- They prevent heat transfer thanks to improved insulation.
- They prevent moisture or air from passing through the facade.
- They allow natural ventilation to cool interiors.
Steel – or recycled steel – and aluminium are just two examples of materials used to create modern and energy efficient facades. They find applications with expanded metal meshes designed for aesthetics and energy efficiency requirements.
Expanded metal enhances thermal insulation and reduces thermal loss. At the same time, it facilitates ventilation and becomes a solar shading solution, acting as a barrier against solar rays in the hottest period of the year.
The energy efficiency lasts over the years since expanded metal has a long durability thanks to the processes with which it is made, such as anodizing, to protect the final product from atmospheric agents.
