High performance homes consider a whole house approach, including design.
By Julia Malisos
People often ask if design is sacrificed when building high performance homes. The short answer is no. Your question now may be, what are high performance homes (HPH)? HPHs are designed to optimize systems resulting in better energy efficiency, durability, life-cycle performance and occupant quality of living. A HPH considers a “whole house approach,” which includes appliances, electronics, lighting, insulation, air sealing, heating, cooling, water heating, windows and doors. Cool roofs and exterior paint color can also contribute. Does design need to be sacrificed to address these components? No, but it may cost a little more up front. The result, however, is long term savings due to lower utility bills, less maintenance, more durable building materials and healthier residents.
Navigating the whole house approach is best understood by breaking down each element and realizing that the most effective strategies are done within the walls, hence, beauty from within.
Insulation and sealing is technical, but crucial for high performance success. Minimizing any leaks through exterior walls, windows, doors or even vents will avert wasted energy, lower utility costs and prevent unnecessary mechanical system use. The Environmental Protection Agency estimates that homeowners can save an average of 15% on cooling and heating costs (or an average of 11% on total energy costs) by air sealing their homes and adding insulation to attics and floors over crawl spaces and basement rim joists. Insulation that is poorly installed or not sufficient for the home’s climate zone, can result in hot spots, cold spots or air leakage. When installed properly and with a high-enough R-value (don’t worry, I’m getting there), insulation can help reduce allergens, noise, control humidity (reducing mold/mildew risks) and enhance comfort.
House insulation ratings are based on R-values; and determining what type of insulation is installed should be based on regional climate. Inevitably, cost may become a factor for insulation choices. R-values are awarded based on thickness and density of the insulation material. There are four common types of insulation: blanket, blown, rigid foam board and expanding foam. R-values are a way to compare these products; higher R-values equate to more effective energy loss reduction. Unfortunately, the higher the R-value can also mean a higher price point.
“People often ask if design is sacrificed when building high performance homes. The short answer is no.”
Similar to insulation and sealing, heating/cooling systems play an important role in HPHs. The HVAC serves as the mechanical respiratory system of the house accounting for some of the largest energy expenses. HPHs should have “right-sized” HVAC units, meaning a system that is not too large so that it uses extraneous energy and not too small that it fails to provide comfortable and effective air circulation and temperature. Air filters should be MERV 13, at minimum and ducts properly sealed and either insulated or within conditioned space. Additionally, ducts must be sealed during construction preventing pollutants from entering the system. Blower Door Tests are performed as part of inspections as they are effective in checking for air leaks, an important step toward building an HPH.
Windows and doors can impact aesthetics. However, when it comes to HPHs, it is the U-Factor and low-e coatings that should be considered. Similar to insulation, windows and doors have a comparison tool designated by a U-Factor. U-factor is the rate at which a window, door or skylight conducts non-solar heat flow. The lower the U-factor, the more energy-efficient the window or door. Also similar to insulation, climate should be accounted for when making decisions.
According to Energy.gov, water heating accounts for about 18% of a home’s energy use. Implementing energy saving strategies such as tankless water heaters, hybrid water heaters or solar thermal systems, can reduce monthly bills and unnecessary consumption. Also, along these lines, low-flow plumbing fixtures should be installed.
Appliances that are ENERGY STAR rated typically qualify and contribute to energy and water efficiency. Smart home technology such as smart thermostats and irrigation systems enable customized settings based on weather, occupancy time and daylighting. Smart technologies can make a house more cost and energy efficient, engaging house systems only when needed, reducing wasteful consumption.
Lighting and daylighting also contribute to HPHs for energy efficiency and occupant productivity. These should be accounted for during design, ensuring the proper fixtures and windows are in place.
Design does not have to be forfeited with the vast amount of product choices available, and although it may cost a little more initially, the long term benefits will continue to add up. Beyond green is the HPH, and beyond its exterior appearance lies the true beauty within.
Julia Malisos, LEED AP is a Principal- Planning/Community Design at WHA Architecture, Planning and Design with offices in Newport Beach, Long Beach, and San Ramon. Julia can be reached at email@example.com