The Process

A: Preparation (Steps 1 and 2)

Step One: Planning and Design

Smart homebuilders begin with the energy efficiency in mind. Early in the process they invest heavily in determining the best balance of design, features, location, targeted homebuyer, desired sales price, energy efficiency and comfort. It is important to note that designing and building a home that utilizes energy and water efficiently does not mean sacrificing a home's aesthetics or amenities. Homes of any architectural type can be built to high standards of performance.

Given the rise, and fluctuation in electricity and gas rates, concern about energy operating costs (utility bills) for homeowners is a hugely important consideration for buyers. With good planning and a firm grasp on the processes and current building technology, your homebuilder is at the forefront of the best value decisions that create stylish, comfortable homes that are also energy efficient.

Step Two: Commitment and Training

Building an energy-efficient home is not an accident. Some efforts of energy efficiency require significant financial investment and choices among products or vendors. Many of the important details are small detail elements of the individual processes involved among the various trades who provide services for homebuilding.

Many of these processes are not hard to perform. For example, ensuring the home envelope, which is the boundary between the conditioned portion of the home and the unconditioned area, is sealed. Another example is installing insulation with the lowest amount of compression and voids. Another "not hard to perform" task is sealing the connections of the ductwork.

Individually, none of these elements have a major impact on the energy efficiency of the home. Collectively, they have a significant impact on the building structure, the energy performance, the durability and comfort level. To ensure compliance on a consistent basis requires a steadfast commitment from the top echelon of each building organization and rigorous attention to detail at the job site. As a result, one important commitment from Efficiency Promise Homebuilders is the ongoing training efforts focused on the builders and trade contractors. It is this team who collectively supervises the work and performs the construction of your home. This training is both structured and unstructured and is offered in both classroom and on the job site.

Efficiency Promise Homebuilders go farther and employ independent home energy rating companies to support the commitment to detail at the job site and to provide job site inspection and training on the most critical elements of energy efficient home building. Efficiency Promise Homebuilders have committed to the continuing effort to understand and utilize the building industry's best practices and the ongoing national research in how best to apply emerging knowledge of building performance. With those efforts, the Efficiency Promise Homebuilders, their construction leadership and their trade contractors will work hard to deliver consistent quality and energy and eco-efficient upgrades where they make economic sense and add to the value of your home.

B: Constructing Home - Key Components & Systems (Steps 3 - 7)

Step Three: Energy-Efficient Air Conditioning and Heating

In Texas, energy usage centers on the home's air conditioning and heating system (HVAC). The HVAC system is designed to provide comfort throughout the year - but particularly in the summer and winter. There are four elements of the heating, ventilating and air conditioning process:
  1. Design/equipment selection
  2. Proper installation
  3. Confirmation of tight duct systems
  4. System commissioning/start-up
Design begins with using the "Manual J". It is a calculation designed to determine the appropriate requirements for heating and cooling and how best to distribute the air around the home. This is a collaborative process between the building design team and the air conditioning/heating contractor and takes into account all the elements of the efficient design that will impact the selection of the equipment and final performance.

"Manual J" is both a process and a software program. Using it, a contractor calculates the heat loss from the building through the wall, and ceilings, ductwork, infiltration through windows, doors and other penetrations. At the same time, the program calculates the heat gain in to the building from sunlight, people, lights, appliances, doors, walls, windows and infiltration through wall penetrations. Design conditions and equipment performance characteristics for the area are used as inputs in to load calculations and the proper selection of equipment.

Efficiency Promise promotes "right-sized" air conditioning and heating system design and installation. This is where the HVAC contractor uses the "Manual J" to carefully match the system capacity to the home cooling needs. Homes that include good insulation, tight air sealing and high performance windows along with properly sealed ducts can significantly reduce cooling loads. As a result, smaller, less costly air conditioners can be installed.

It is true that oversized air conditioners can provide cooling more quickly; however oversized air conditioners short cycle. Short run times cause extra wear and tear on the compressor (shortening life) and generally increase the cost of electricity. Right-sized air conditioning systems meet the goals and requirements of using less energy, less pollution, a smaller environmental footprint and, generally, last longer before requiring replacement.

The major goal of duct design is to provide proper air distribution throughout a home. The duct should be designed to facilitate airflow - minimize friction, turbulence and the leakage of air from the system. The optimal duct system is also "right-sized".

Installation: Proper installation is the responsibility of the HVAC contractor. This is one of the most important trade contractor decisions made by builders and much thought goes into the selection of the team responsible for proper selection and installation of equipment and the duct system. In Texas, Efficiency Promise Homebuilders mandate insulated flexible ducts that only require air sealing at connections. Those connections are then sealed with the best combination of approved UL 181b duct sealing tape (standard "duct tape" is not an approved sealing material) or Mastic (a fibrous coating applied at time of installation) and, in some cases, both.

Sealed or tight ducts help significantly by providing the cooled or heated air to the conditioned space and not to attics or crawl spaces. It helps improved the quality of indoor air by reducing the intake of pollen and dust in addition to cutting energy loss.

Step Four: Installation of High Performance Windows

Windows typically comprise 8 to 25 percent of the exterior wall area of new homes. Research studies report that windows in cooling-dominated climates (like Texas) can account for a significant amount (up to 50 percent) of the cooling load. In recent years, many technological advances have been made that enhance the thermal performance of windows. These technologies include low emissive and solar control coatings, improved window framing materials, improved thermal breaks and edge spacers. These enhanced window products are now available to quality homebuilders at prices that make them an extremely good value for homeowners.

Windows can improve the thermal performance of home by minimizing heat loss in winter and by minimizing solar heat gain in cooling-dominated climates. Solar Heat Gain Coefficient (SHGC) is a measure of the amount of solar energy that a glazing material allows to pass. In Texas, SHGC numbers below .40 are considered very good windows and are substantially better than windows installed prior to the year 2000. While the U-Value of a window is important, it is most important in colder climates. That being said, Efficiency Promise Homebuilders select windows that significantly exceed the minimum U-Value for a code compliant window in Texas.

Step Five: Water Saving Plumbing Fixtures

The Energy Policy Act of 1992 mandated that new homes have more energy efficient water fixtures. Since 1992, new homes have had 1.6 gallon flush toilets and 2.5 per gallon/minute flow water faucets, kitchen faucets and lavatory faucets. Used properly, these plumbing fixtures can dramatically reduce water usage and the resultant utility bill from water.

Step Six: Sealed and Tight Homes

The purpose of having a sealed home is to reduce air infiltration and the negative effects of too much air leakage. Effectively, the goal is to create a substantially continuous air barrier - a combination of materials and connections that when linked together - create a tight building envelope. The "building envelope" is the boundary between the conditioned portion of the home and the unconditioned area.

The air barrier should seal substantial leaks throughout the "building envelope". Many key sources of air leakage are hidden from view. They could be located behind tubs and other bath fixtures, in dropped ceilings (or other places in the home where ceiling height changes). There are numerous nooks and crannies where it is of benefit to have multiple inspections to find, seal and insulate these areas. Sealing "thermal bypasses" in these areas are significant for achieving the overall important level of reduction air leakage in the home and improving the performance of the insulation materials.

Step Seven: Thermal Insulation System

Thermal insulation (in combination with a substantially sealed envelope) is intended to reduce heat loss and heat gain through the transfer of heat through walls, doors and ceilings. Proper insulation will reduce the cost energy by keeping out the hot in the summer and keeping in the warm during the winter. Insulation in walls is usually provided by fiberglass "Batts" often (but not always) backed by craft paper.

Sometimes, wall insulation will be with blown-in cellulose or blown-in foam. Ceilings are generally insulated with R-30 to R38 blown-in insulation.

C: Confirmation and Certification

As previously stated, many of the fundamental items for the construction of energy-efficient homes are created from hundreds of tiny steps - touching almost every trade - to construct the home. To help coordinate, train the contractor base, inspect performance and provide confirmation testing to create your Efficiency Promise Guarantee, your builder voluntarily employs third-party Home Energy Rating Companies to help provide for quality and consistent performance. Home Energy Rating Companies are trained and certified to help builders focus on the first 6 steps of energy smart building and are certified through a national process from the Residential Energy Services Network.

The actual installed features and field results are entered into a software energy model and the custom guarantee for your specific address is created.

Step Eight: Inspections and Performance Testing

The Home Energy Rater works with your builder and provides (at least) two structured inspections and a key performance tests on each home.
  • The first inspection is prior to drywall installation and generally comes after installation of insulation in the walls. The Home Energy Rater inspects each energy related measure in the home. Important data like - on-site energy characteristics, such as insulation levels, window efficiency, window-to-wall ratios, the heating and cooling system efficiency, sealing of the duct work, the orientation of the home and the water heating system - are transmitted for data and captured as fundamental to each Efficiency Promise.
  • The second inspection is after HVAC trim and confirms the HVAC unit installation, plumbing fixtures, reviews duct installation, and confirms that the ceiling insulation has been completed, as well as looks for breaks in the thermal boundaries.
Evaluation, Testing and Certification

A unique feature of the Efficiency Promise is the home tightness testing and duct tightness testing for each and every home in the program. Home tightness testing (often called the blower door test or infrared thermometer) pressurizes the home to ensure that the home performs to the desired range of acceptable tightness. The purpose is to confirm that the home is tight enough to provide for intelligent energy efficiency while allowing enough breathing to support indoor air quality. This test is performed close to the completion of the home. Duct Testing applies the value proportion to the home's air distribution (duct) system and mirrors the benefits.

At the end of the process, the third-party Home Energy Rating firm and your Homebuilder collectively evaluate the final data input into the energy model and deliver a certified and confirmed energy rating. Efficiency Promise uses the actual data to deliver a customer guarantee on energy usage for your heating and cooling.

Disclaimer: The Efficiency Promise commitment is the best possible trade-off between envelope performance, energy efficiency and their impact on first and lifecycle costs. Efficiency Promise and its affiliated builder partners do not claim that all homes will be free of all defects, do not claim that all homes will have only eco-sensitive products. All homes have trade-offs and Efficiency Promise Homebuilders will make choices for the purpose of delivering the most efficient home and the most environmentally sensitive home for the money that a homeowner is willing and able to invest. It is a judgment call on costs, options, lifecycle costs, and environmental impact. Efficiency levels will vary on every home and utility costs will vary based on how the occupants live and operate the home.