In the past, framing has been overlooked as an energy saving opportunity. We know now that conventional framing choices such as wood, concrete and metal often act as thermal bridges and directly transfer heat from interior walls to the outside. The following examples are framing techniques that significantly improve energy savings:

• Advanced framing: reduces material waste and heat transfer by arranging materials to increase areas of insulation and reduce direct pathways for heat to leave the house
• Staggered stud walls: interrupt thermal bridging by alternating studs along the wall, never completely connecting the inside wall to the outside wall
• Double wall assemblies: layer two smaller walls filled with insulation next to each. Constructing walls with 2x6" instead of the standard 2x4" studs creates a deeper wall cavity allowing for more insulation
• Insulated Concrete Forms (ICFs) and Structured Insulated Panels (SIPs): all-in-one wall system with pre-fabricated framing materials that integrate a high-level of insulation
• Raised heel trusses extend the space where the roof meets the wall of a house adding areas that can be insulated

Insulation provides the single greatest opportunity to reduce unwanted heat loss. To support energy savings from insulation, high performance homes rely on two combined techniques—creating more surface area to insulate and selecting better insulating materials. Advanced framing opens up areas in walls, floors and ceilings allowing for added insulation. This advantage is improved upon by selecting insulating materials that have a high resistance to heat flow, also known as R-value.

Two other effective insulation options are spray foam and blown cellulose. Both are applied with high-pressure, forced air and densely pack the entire wall cavity, completely filling gaps around framing materials. Another efficient method, exterior rigid foam, adds a layer of insulation to the exterior of the house. This increases the total R-value of the wall, reduces pathways for conduction (thermal bridging) and prevents condensation that leads to mold and dry rot.

Windows are an essential element of home comfort. They let in much needed natural sunlight and provide necessary ventilation in mild weather. However, single-pane windows are also notorious for energy waste and allow heat to quickly escape to the outside.

Double-pane windows, the current building standard, add a sealed air cavity between two panes of glass. The air cavity acts as an insulating layer and reduces the heat transfer to the outside. High performance triple-pane windows are quickly gaining momentum as the superior energy efficient solution. With three panes of glass separated by two sealed air cavities, heat transfer becomes exceptionally minimal.

A home that is well insulated, but not airtight, performs as well as a winter jacket that is left unzipped. Air sealing must happen in order to realize the energy savings captured with advanced framing and high R-value insulation. It also supports the efficiency of HVAC systems and maintains air quality.

Air sealing is a growing practice with builders and home performance contractors. Typical problem areas are windows and doors, gaps in framing materials and areas where mechanical systems bridge interior and exterior walls. Air sealing starts with prescriptive framing elements, then contractors identify problem areas and seal leaks with caulk or a liquid or foam-applied air barrier. This makes the home airtight.

Success can be demonstrated with a blower door test. A blower door test pressurizes a home and measures air leakage by determining how many times outside air is replaced throughout the house. In an ENERGY STAR certified home, a measurement of four full air changes per hour (4 ACH50) is the required standard with a high performance home testing as low as two full air changes per hour.

In an ENERGY STAR certified home, a measurement of four full air changes per hour (4 ACH50) is the required standard with a high performance home testing as low as two full air changes per hour.

A high performance heating, ventilation, and air conditioning (HVAC) system delivers comfort, maintains air quality and saves energy. It is an important consideration that improves upon the energy savings generated from advanced framing, insulation and air sealing.

Traditionally, HVAC systems have relied on ductwork to deliver heating and cooling throughout the house. However, air leakage and heat loss from air ducts is very common. When ductwork is installed in attics, crawlspaces, garages or other unconditioned spaces, the amount of energy wasted skyrockets. On average, leaky ductwork is responsible for up to 30 percent energy loss.

Today’s high performance homes often feature an HVAC system tightly sealed, incorporates the ducts inside a conditioned space or without ducts all together. A ductless heat pump (DHP) produces up to four times more heat energy than it consumes. Many also have internal filtration systems that trap odors, pollutants and allergens.

A properly insulated and air sealed home creates an interior space that is as airtight as possible. While this greatly increases energy savings, air sealing also restricts the replacement of stale, inside air with fresh, outdoor air. To regulate air quality for the health and safety of occupants, a ventilation system becomes necessary to balance this exchange.

During cold months, a heat recovery ventilator (HRV) improves air quality by periodically exhausting out stale air and indoor pollutants and piping in filtered, fresh air.
Before entering the house, the outdoor air is warmed to room temperature by the indoor air as they travel side-by-side in a heat exchanger that conducts heat between the two. This maintains the quality of the incoming fresh air and also pre-heats it without using the home’s furnace or heat pump for additional energy savings.

The daily activities of taking showers, doing laundry and washing dishes all demand reliable hot water. In most homes, water heating accounts for 14–25% of all energy consumed. Heat pump water heaters offer immediate hot water and save energy. Instead of generating heat directly, as a stove boils a pot of water, a heat pump water heater pulls warmth from the surrounding air and transfers it to water in the storage tank. In mild climates, this technology uses up to three times less energy than traditional electric hot water heaters and is another easy way to cut down utility bills.

Energy-efficient lighting is evolving at a rapid pace. Compact Fluorescent Lights (CFLs), the first energy savers to replace the century-old technology of incandescent bulbs, are quickly being eclipsed by Light Emitting Diodes (LEDs). LEDs produce light by passing electricity through a microchip and can produce over 100 lumens per watt of electricity. When compared with an incandescent bulb that produces 10-20 lumens per watt or a CFL that produces 40-100 lumens per watt, the energy savings is significant.

LEDs are a directional light source and the best choice for tasks such as reading or cooking. Although more expensive up-front, one perk to remember is that the average LED lasts years longer than a CFL or incandescent bulb. Many local utilities also offer cash incentives to lower the cost.