To reduce a building’s carbon footprint and total energy costs while increasing occupant comfort and satisfaction, HMC Architects focuses on improving the building’s envelope efficiency. The envelope is where the productive passing of energy through a building’s exterior, or membrane, can occur. By reducing the trespass that arises through the envelope, the internal building temperature is kept more regular and predictable. This results in more thermal performance and a more energy-efficient building design.
Why is a Thermally Efficient Building Envelope Important in Energy-Efficient Building Design?
An efficient thermal performance building envelope offers several advantages. It reduces energy usage and expenses and gives building managers more control over the temperature in areas, increasing tenant comfort.
While the thermally efficient design may be more expensive up front, operational expenses may be lower in the long run, and productivity may increase. According to research published in 2014 by the International Energy Agency, “the value of the productivity and operational advantages generated [from energy-efficiency measures] can be up to 2.5 times (250%) the value of energy savings” (depending on the value and context of the investment).
Operating an HVAC system daily may be expensive, especially if your facility is large and in a hot or cold region. HVAC and other systems can work less hard when thermal performance is efficient and included in the design.
Reduced Energy Consumption
An efficient thermal performance building envelope significantly decreases a structure’s carbon footprint by using less energy to heat or cool it. A system with high R-value insulation in the walls and roof and insulated glass units with low solar heat gain, for example, will prevent too much heat from fleeing the building during cold weather and from entering the building during warm or hot weather.
When designing Middle College High School in Los Angeles, California, we employed thermally efficient materials, such as R21 wall insulation and R38 roof insulation, to retain cool air inside even as temperatures outside climb. We also provided window shading on all of them. These design decisions reduced energy use and helped the school achieve LEED Gold certification.
A green roof also protects the building exterior and reduces energy usage by serving as an insulator. During the summer, the building is shielded from sun radiation. This implies the building will require less air conditioning to stay cool. Because of the additional soil layers, a green roof decreases heat loss from within a structure during the winter.
While a green roof might assist in reducing energy use, it can also increase water consumption—plants require a steady water supply to keep healthy. Yet, there are solutions to this problem. When designing Portola High School in California, we linked the building’s green roof to an air-handling unit. The air-handling equipment kicks in and cools the structure on hot days. Nevertheless, much water is created during the process and ejected via the condensing unit. As a result, we collaborated with mechanical experts to catch this water and direct it to the green roof for watering.
Once saturated, the green roof may passively cool the building for the remainder of the day and, in fact, even pre-cool the building for the next day, minimizing the school’s reliance on the air conditioning system.
Regardless of building type, room temperature affects inhabitants’ performance, emotions, and general well-being. In hospitals, for example, comfort promotes faster healing. Employee productivity in office buildings rises when the temperature is well-controlled.
Summer heat can have a detrimental impact on student performance, particularly test results, in schools. Children can concentrate better when the temperature in the classroom is between 65 and 75 degrees Fahrenheit. Ideally, ideal room temperatures may be maintained by adopting correct insulation, daylighting, and natural shading methods in thermal-efficient building design.
While architects and building managers continuously strive to produce energy-efficient buildings, planning for energy efficiency and thermal comfort entails certain challenges.
The Difficulties of Creating Energy-Efficient Buildings
While there are several advantages to thermally efficient design, achieving them may be difficult. To design a high thermal performance building that meets or surpasses energy-efficiency criteria, architects must overcome logistical challenges, material prices, and restricted building rules. The following issues may complicate your design process; thus, examine them early in the planning process:
Some people need to familiarize themselves with new thermally efficient materials like Insulated Concrete Forms (ICFs). The R-value of the wall assembly is increased by using ICF, which is concrete sandwiched between layers of polystyrene foam. If a building or planning administration is unfamiliar with this information, they may be hesitant to accept it.
The environment has a significant influence on the construction of energy-efficient buildings. The appropriate material must be chosen to resist the impacts of the climate on the structure in locations where the temperature is very warm or cold most of the year. Daylighting is also a consideration. As a result, the good site must be addressed, as locations inside the structure with direct sun exposure will be warmer than those away from direct solar exposure.
The labor and material costs
Not only must you examine the materials that will be best for the environment and occupant comfort, but you must also consider the cost of supplies and the time necessary to install them. For example, while wood is now less expensive than steel, wood framing may take longer to construct than a steel frame. On the other hand, steel absorbs and releases heat faster than wood, making it less effective in hot climates. As a result, you’ll need to balance the advantages and disadvantages of each.
Government regulations may limit the materials that may be utilized in building design. In California, for example, architects designing schools must adhere to very tight requirements. New structures in that state are also obliged to fulfill Title 24 criteria. These criteria should be open for experienced architects because they have been in place for years and are very straightforward to implement with good planning.
Meeting zero net energy standards may prove difficult. In California, the Public Utilities Commission has mandated that all new commercial buildings and substantial renovations of existing structures achieve zero net energy (ZNE) performance beginning in 2030. The change will enhance energy efficiency by 60-70 percent, improve air quality, and reduce greenhouse gas emissions.
Thermal performance is not a new notion in the construction industry. Still, it is gaining traction as a vital component of energy-efficient building design – and one that we at Buildtec embrace.
Thermal performance is defined by Australia’s national research organization, the CSIRO, as the amount of heating or cooling necessary to make a home a ‘pleasant’ place. Thermal performance in Australia is measured using an energy star rating system, with the number of stars granted scaling upwards to an ideal value of 10 stars. The average star rating for homes in South Australia is 6.3, which is slightly higher than the national average of 6.2, according to CSIRO’s Australia Housing Data Portal. If you found this article informative, you may also want to read our blog on weatherboard cladding. You’ll certainly like it.