Façade is one of the most important factors in certain building types, that can completely transform the occupant experience and the energy performance of the building. The Whole Building Design Guide showcases that the facade can have up to 40% impact on the total energy use of the building. In addition to the energy use, the facades also significantly impact the occupant productivity withing a building and, of course, the appearance of the building. There are many factors that go into creating a high-performance façade. In this article, we outline the top 5 things a design team should consider.
1. Impact on Daylight and Views
Facades not only impact the energy use of the buildings they belong to, but they also have an incredible amount of impact on the daylight penetrating inside the building. Daylight can be broken into daylight quantity, measured by spatial daylight autonomy and daylight quality measured by annual solar exposure. The building massing, window to wall ratio, orientation of glass, visual transmittance of glass, solar shading strategies and more can have a significant impact on the amount and quality of daylight penetration. Both daylight and views can have a drastic impact on the real estate value of the building. Multi-family, hospitality, offices, labs, education, and healthcare projects with higher quality of views and daylight are associated with higher productivity, faster recovery, and more wellness. The LEED Rating System highlights the importance of daylight and views.
2. Energy Use
A building’s energy use refers to the energy required to operate and sustain it. Depending on the facade design and the active and passive strategies implemented, the energy use of the building can drastically vary. This leads to a much higher energy cost, making the building expensive to operate. Designers can significantly reduce this expense by implementing sustainable strategies early on in the design process. Evaluating the building’s location and orientation to the sun as well as the materials and construction methods used can help determine the best path towards an energy-efficient façade. Solar Shading is a powerful passive strategy that if fully utilized can have a massive impact on your overall building’s performance. However, this is dependent on a multitude of factors including the amount of shading added and the program that is in the building. Some mis-equate a fine-tuned solar shading strategy applied throughout a project, to add 6” fins on east and west facades.
Solar shading encompasses a large scope of design strategies from Building Massing, Orientation, WWR (Window to Wall Ratio), Glazing Placement, Envelope Properties, Fenestration performance, and traditional shading elements (fins and overhangs, light shelves, shadow boxes, and cantilevers), modern shading elements (frit, interior shades, dynamic glass). So, it makes sense that picking one strategy out of the lot will not hold a candle to employing the entire package.
Occupant comfort is the final test of the success or failure of a project. Buildings are made specifically for people to work, live, and socialize in. Therefore, it is critical that they are designed to meet the needs of their occupants. To prioritize occupant health, comfort, and productivity, a high-performance façade must take into consideration the amount of natural lighting and passive heat gain that enters the building’s interior. Conducting radiation and Glare studies during the early stages of the design process can help design teams select the right strategies to achieve this goal.
4. Acoustic comfort
Acoustic comfort is the well being perceived by a building occupant in regard to the acoustic quality of their environment. The WELL building standard highlights that acoustics have the ability to significantly reduce occupant productivity. Despite its impact, this metric is typically considered only when the project type is a theater or auditorium. One great factor of acoustic comfort is façade materiality. Providing noise reducing insulation or materials with similar properties can minimize noises and enable higher productivity levels for the building users.
5. Embodied Carbon
In addition to the energy use, which helps reduce the operational carbon, the embodied carbon refers to the Greenhouse Gases (GHGs) emitted during the extraction, manufacture, transportation, construction, replacement, and deconstruction of building materials, together with the end-of-life emissions. Between 39%-80% of a building’s total carbon footprint is a result of the embodied carbon from building materials. If evaluated early in the design phase, 80% of a building’s embodied carbon can be reduced.
As energy codes and other architectural requirements become more stringent, architects must place an increased focus on energy efficiency. While balancing aesthetics, energy use, cost, and occupant comfort is a challenging task, many designers are turning to building performance and energy modeling tools to gather project data and run analyses to determine the best design that meets their sustainability goals.
To learn more about best practices for sustainable building design, check out Cove.Tool's resource center.