Construction Business Owner, February 2008

Editor’s Note: This is the second of three articles on practical, cost-effective, green building techniques by Jeff Binder of greenbuildingblocks.com.

That should be good news for builders. In many ways, the economies of scale inherent in larger projects—less waste and greater efficiency—are already green ideas.

Build on that foundation with certifiably green ideas like eliminating air conditioning (in the right climate), clustering wastewater treatment and using modular principles to lower cost and complexity, and the idea of sustainability on a national stage is one step closer to realization.  

All across America, sustainable multifamily developments are hitting the market: Forbes Lofts near Boston, MA, Glenwood Park in Atlanta, GA, and Issiquah Highlands near Seattle, WA. It’s green building on a massive scale.

In this series, we set out to identify green building practices that actually cost less than conventional residential construction. It turns out that this is much easier to do in multifamily developments.  

The implications are enormous. According to the U.S. Green Building Council, green buildings reduce energy costs by 30 percent, carbon emissions by 35 percent and water usage by 30 percent in their operation. A recent study says they only cost 2 percent more to build.

Listed below are five more green building techniques that actually cost less.   

1. Eliminate Air Conditioning

Most boomers grew up in houses that were not air-conditioned. Therefore, it’s not a totally outlandish suggestion to eliminate it in a new house. A home buyer’s desire for AC is assumed by builders, even in climates where it’s used for just a few days out of the year.

Given the right climate and the right presentation, a strong case for the elimination of AC can be made across much of the United States. Savings could top out at $10,000 per residence if you factor in systems, ductwork and labor. 

Stoic self-denial is not a requirement. Using principles of passive solar design, enhanced ventilation and thermal mass, builders can use siting and the orientation of the house to make interior environments comfortable year-round. In California, Alternatives to Compressor Cooling (ACC) has proven that using cool night air to cool exposed concrete slabs can eliminate air conditioners in most of the state.

That’s a great thing since air conditioners, which use only 10 to 12 percent of the energy in a home, are responsible for 43 percent of the residential peak load.  

Those who live in the Southwest have long been familiar with “swamp coolers.” Now, many homeowners are pairing solar chimneys with geothermal cooling (drawing cool air from an underground cavity) to keep their homes comfortable.

In the Northeast, one major condominium development just outside of Boston has eliminated air conditioning altogether, counting on through ventilation and air-scoop windows, a run-off basin that helps cool the interior courtyard and low-solar-heat-gain glazing.  

In the Gulf states, eliminating AC may be a radical proposal. Therefore, right-sizing HVAC systems is the sustainable alternative. Installing code-plus insulation allows builders to spec and install less expensive systems to heat and cool the house. Since it is the second-largest energy sink in residences (refrigeration being the first), it makes sense to reduce, if not eliminate, air conditioning use.

2. Make Multifamily Modular

Multifamily modular residences have come a long way since the Habitat project at Expo ’67 in Montreal. That twelve-story pile of terraces and setbacks contained 158 units and was assembled by a crane—and it cost a bundle.

But the multifamily modular industry has gotten more sophisticated, along with the rest of the building trades. Among the chief advantages of building the units in a factory is the inherent cost-effectiveness and their tight timelines.  

It’s the ideal application of automation—limited floor plans, repeatable features and higher construction standards in a controlled environment. On site it means less materials waste, no weather delays or damage, better inventory control, virtually zero theft, volume purchasing, tighter tolerances, lower cost and a rapid (and far more predictable) installation cycle.

“We call it concurrent construction,” says Jeff Myers of Deluxe Building Systems. “While you’re preparing the foundation, we’re building the structure in a climate-controlled, automated factory.”  

In fact, Deluxe cut an entire year off the development cycle for one resort hotel, enabling the developer to realize hundreds of thousands of dollars in revenues a year earlier than typical stick-built construction would have allowed.

Avis Homes, another multifamily modular supplier claims to have installed an entire forty-two-unit apartment building in twelve days. Builders at the mercy of everything from weather to labor shortages find a highly compelling argument for the predictability of this construction method. 

 

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