Here's a marketing tip: Stop sending press releases touting LEED-rated buildings. I’m not alone in saying this. During a panel discussion at the recent Society for Marketing Professional services conference in Denver, my fellow speakers—editors from Engineering News RecordBuilding Design & Construction, and Architectural Record—all agreed that garnering a LEED rating simply isn’t newsworthy anymore. Our point—if I may speak for the group—wasn’t that a LEED rating has lost its inherent value, but that it’s become relatively commonplace. That’s a good thing. It’s a sign that more architects are designing green and more of their clients are paying for the privilege.

But when it comes to advertising your sustainable bona fides—and here I speak for myself—these days there are better ways to get a busy editor’s attention. LEED is an aspirational tool, a kind of sustainability forecast. It only holds true until move-in day. From that moment forward, for a building’s entire operational life, a LEED rating has little value except for marketing. To gain an actionable, four-dimensional understanding of the value of sustainable design strategies, architects, building owners, and facility managers have to invest in long-term performance evaluations.

How much energy and water does a building consume? How much waste does it produce? What is its carbon footprint? These are the kinds of questions contemporary architects must be prepared to answer in order to make the sustainability movement truly sustainable, as ARCHITECT editor at large Edward Keegan asserts in this month’s cover story, “Promise vs. Performance." If we can’t back up our green rhetoric with hard numbers, we’ll lose credibility with (and commitment from) tenants, investors, and other client groups. This audience is nearly captive. They are increasingly intrigued by the potential health benefits of green architecture and cost savings over the life of a building. But if the profession is going to tout such advantages, it had better deliver. The burden of proof lies with architects.

It’s easy to grow overwhelmed by conflicting claims about sustainability. Witness the ongoing debate over PVC, which contributing editor Bradford McKee addresses in “Raw Materials: Vinyl." Is it a toxic offender, or a recyclable wonder product? Similarly, big box stores, with their acres of asphalt, are hardly environmental models, but abandoned Wal-Marts and Kmarts can take on second, productive lives, as artist Julia Christensen shows in “Big Box Reuse”—so does that make them, in a sense, green? In many such cases, there is no straight-line answer. But the science of building performance doesn’t have to be complicated. The solution is to establish simple measurement systems and routines—to provide clear data that back up the promise of the design. There are plenty of  existing, low-cost evaluation tools, from monthly electricity bills and employee attendance records to toilet valves that track water consumption and lighting controls that monitor energy use.

Occam’s razor—lex parsimoniae—holds that all things being equal, the simplest solution is the best. Several of the experts we interviewed for “Promise vs. Performance” made the exact same assertion, that buildings of the 1920s are as green as or greener than the latest LEED-rated glass tower. I’ve been pushing this idea for years. When I was curator at the Chicago Architecture Foundation, I used Burnham & Root’s landmark Rookery Building of 1888 as an object lesson to explain daylighting and passive ventilation to lay audiences. If architects were able to design well-ventilated, well-lit skyscrapers decades before the advent of air conditioning and fluorescent lighting, there’s no reason we can’t design equally simple, sustainable buildings today. We just need to prove that they work.