Windows For Multifamily Housing

Single-family homes or duplexes typically attract the most attention from energy efficiency programs such as ENERGY STAR or utility rebates. Nevertheless, the importance of energy efficiency, including efficient windows, for multifamily housing is increasingly being recognized.

The term multifamily is often understood to apply to buildings that consist of five or more housing units. These buildings make up about 18% of the nation’s housing stock, and demand in this market segment is high.

Demand for Multifamily Housing

Multifamily housing has perhaps been one of the few relatively bright spots of the housing market in 2010 and 2011. The National Association of Home Builders forecasts that a slow but steady rise in multifamily construction will continue through 2012. This rise in construction is moderated by tight access to credit. As a result, demand for existing multifamily housing is high as well.

An economic reason for this demand is the interest in renting – common in the multifamily sector – due to uncertainty in home values, limited finances and the need for flexibility in the event of relocation. Home buyers also have grown more cost-conscious, and often find condos to be more economical than single-family housing in terms of purchase price,utilities and transportation costs.

Multifamily housing also can be a very attractive choice if the location is within vicinity to work, stores and entertainment and if the buildings are in good condition. The demand for higher-quality multifamily housing is driving efforts to refurbish existing multifamily housing and to design new attractive high performance buildings.

Energy Efficiency Needed

Energy efficiency plays an important role in making multifamily housing more attractive and affordable. Although energy expenditures per person are usually lower among households living in multifamily buildings than among those living in single-family homes, average energy consumption per square foot of living space is actually higher than in single-family homes.

Thorough energy efficiency retrofits can achieve improvements of 30% to 75% in many multifamily buildings (check out an example of such a deep energy retrofit). In most climates, both hot and cold, efficient windows are central for boosting occupant comfort and reducing energy costs.

Efficient Windows for Multifamily Housing

On average, the windows in existing multifamily buildings are less energy efficient than those in single-family homes. Among multifamily housing units, more than half still have single-pane windows, as opposed to less than 40% in single-family homes. Surveys by the Energy Information Administration found that only about 10% of multifamily housing units have had some or all of their windows replaced.

Why this lag in window performance among multifamily homes? In many older, centrally heated buildings without adequate temperature controls, operable windows may be the only available thermostat during the winter, making the case for efficient windows less compelling. Moreover, most occupants of multifamily homes have little say over their windows. More than 80% of multifamily housing units are rented, leaving window choices up to property owners whose incentive to maximize window performance is less than that of a homeowner. Also, capital often is in short supply for multifamily buildings with low- and moderate-income renters.

Even in owner-occupied condo buildings, the process for replacing windows requires much more than just a trip to the local lumberyard. Particularly in larger buildings, the interests of multiple parties, as well as structural and potential historic requirements, must be taken into account. Yet these barriers do not diminish the role that window efficiency plays for heating and cooling energy use and for occupant comfort.

A wide range of window types are used across the multifamily sector depending on building location, size, height, façade types and architectural preferences. Energy-efficient options are available regardless of window type. Luckily, energy efficiency programs like the ENERGY STAR Multifamily High Rise Program and the DOE High Performance Windows Volume Purchase Program encourage the use of energy-efficient windows across different types of multifamily buildings.

For More on Windows

This article was adapted from the Summer 2011 Word on Windows, which is the Efficient Windows Collaborative's newsletter. The Efficient Windows Collaborative is the Alliance’s consortium dedicated to increasing the market share of high-efficiency windows in both the residential and commercial sectors.