BACK PAGE BASICS: Steps to Net-Zero-Energy Building Design

Beginner

Building and designing affordable net-zero-energy (NZE) homes involves several integrated steps. NZE can use commonly available building materials and equipment, along with easy-to-learn building strategies.

Smart Design

Smart design is crucial, as the design will dictate everything else that follows. Good design includes understanding the site’s benefits and limitations. Simplifying the building footprint and roofline can also be part of smart, efficient, and cost-effective building.

Use Energy Modeling

During design, energy modeling software should be used to estimate the home’s energy use. Based on the results, design choices can be made or modified to balance building performance and construction cost.

Super-Seal the Building Envelope

Super-sealing the building envelope is the most cost-effective measure for improving the energy efficiency of an NZE home. Several proven air-sealing approaches are available. Choose an approach that matches your climate, skills, and budget.

Heat Water Wisely

Installing low-flow fixtures and water-efficient appliances helps decrease water-heating loads, which can then be offset by renewable energy technologies like solar hot water collectors or a solar-electric system.

Use Well-Insulated Windows & Doors

Windows and doors are like big holes in a well-insulated, airtight building envelope. Control their heat loss and gain by selecting appropriate products, and carefully sizing and placing them.

Use Sun & Shade for Solar Tempering

Using the sun for heating through south-facing windows during the winter lowers heating costs. Shading those same windows in summer lowers cooling costs. “Solar tempering” takes advantage of the sun’s heat without maximizing solar storage with thermal mass. Some homeowners want to offset as much of their heating load as possible by adding thermal mass.

Create an Energy-Efficient Fresh Air Supply

A continuous source of fresh, filtered air and moisture control are critical to an NZE home’s success. Energy-efficient ventilation systems, known as heat- or energy-recovery ventilation systems, expel stale air while transferring exhaust-air heat into the incoming fresh air.

Select an Energy-Efficient Heating & Cooling System

One good choice is an air-source ductless heat pump, also called a minisplit heat pump. These systems are efficient and don’t have the shortcomings of central, forced-air systems or the high cost of larger heat pumps.

Install Energy-Efficient Lighting

Use daylighting when practical, and LED lights for supplemental lighting. They are more energy-efficient than compact fluorescent lamps, last many years longer, and contain no mercury. Select the right LED lights for the task, locate lights strategically, and use natural light as effectively as possible.

Select Energy-Efficient Appliances

Appliances and plug loads may account for up to 60% of the loads in an NZE home. Selecting energy-efficient appliances and managing “phantom” plug loads is essential. Phantom loads continue to draw energy whether or not the devices are being used. These can be curtailed by placing them on switched outlets, plug strips, or timers.

Use the Sun for Renewable Electricity

In most locations, a grid-tied PV system provides the most cost-effective form of renewable electricity required for an all-electric NZE home.

—Adapted from The Zero Energy Project (zeroenergyproject.org), a nonprofit educational organization that helps homebuyers, builders, designers, and real estate professionals radically reduce carbon emissions and energy bills by building NZE homes.

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