Building walls includes numerous parameters such as visual, thermal comfort, quality of the natural light, acoustic performance. Sustainable facades protect from the external environmental influence and keep indoors comfortable conditions with minimal energy consumption. Thermal heat transfer, solar heat preservation, air leakage, and access of natural lighting determine the facade’s energy efficiency. The facade design and materials depend greatly on the climate and location.
With the constant resource depletion and environmental pollution, the need of using sustainable strategies and technologies in contemporary facade construction has become obvious. The buildings’ walls contribute to the comfort and energy-efficiency factors accounting for over 50% of its energy use. The facade protects from the external environmental impact and maintains satisfactory internal conditions, which serve for the benefit of the occupant's health and productivity. Walls’ construction and design are not limited to the aesthetic look, they are supposed to serve practical functions such as efficiency, insulation, strength, durability, easy maintenance, resistance to fire, moisture, pests. High-performance facades imply ecological materials selection, innovative technologies, attention to the details in the architecture and design. The walls’ design strategies and material selection depend greatly on the location and climate.
The properties of the energy-efficient facades:
natural light penetration into the building,
ability to store heat in the walls,
quality insulation stopping the heat transfer,
prevention from the air and moisture entering facade,
natural ventilation allowing to cool indoors.
Design determinants for the buildings’ walls
Aesthetic look. The facade represents the identity of the building. Its shape, color, texture, patterns should form a harmonious structure with the character and functional features hidden within it.
Structural aspects. Building self-weight, weather load, seismic factors, material strength, construction height should be considered in the walls design process to extend the building’s lifespan.
Safety. The building’s safety depends not only on its structure but also on the impact of the outside factors such as transportation, other buildings outside, the building's maintenance machinery, and the general public. Facade systems testing and evaluation of the outside factors help avoid safety issues and develop necessary protection measures.
Acoustic performance. The important functions of the walls are the attenuation of the external noise and traffic and prevention from self-generated noises, such as friction and echo.
Thermal performance. Building facades have the potential of improving energy efficiency and reducing energy consumption and bills significantly. The decisions in the design at the preconstruction stage improve thermal performance.
Sustainability. The use of the ecological recyclable facade materials, which are produced locally by environmentally responsible manufactures are important factors of the construction of the walls, which are invisible in most cases but add additional value to the building and reduce the negative environmental effect.
Two main wall materials categories:
opaque consisting of solid materials such as stone, metal, concrete panels, masonry,
glazed consisting of transparent glazing materials and framing components including curtain walls.
The popular examples of the alternative facades:
The cork facade is an acoustically absorbing and high-insulation solution common for the floors but recently starting to be used for the exterior walls,
The green facade is incorporated with the plants in the wall design changing the exterior and filtering the air,
The kinetic facade is created with a shutter system adjusting to the natural light.