Retroficiency, the startup that promises a “low-touch” software approach to picking the best and cheapest way to upgrade building energy efficiency, has just achieved a few significant milestones, announcing new customers including big energy services company SAIC, as well as a tally of 25 million square feet of commercial floor space having been evaluated by its software.

Not bad for a company that just came out of stealth with an $800,000 angel round in March. Just compare its 25 million-square-foot tally to that of Scientific Conservation, another building energy software startup, which had amassed 15 million square feet under management as of last November, after being active in the market more than twice as long.

Of course, that’s not exactly an apples-to-apples comparison. While most building energy software is designed to interface with a host of sensors, controls and building management systems, startups like Retroficiency and FirstFuel -- which raised $2.4 million in VC last month -- say they can identify efficiency improvements without sending a single energy auditor into a building or installing a single sensor.

In the penny-pinching world of commercial real estate, cutting down on those up-front analysis and planning investments could expand the market for energy efficiency in a big way. Whether such light-touch approaches to analyzing building energy waste can hold up against the promises of continual, hands-on building energy management from big players like Schneider Electric, Johnson Controls, Honeywell, Siemens, and IBM remains to be seen, however.

But right now, Boston-based Retroficiency sees itself fitting in quite nicely with the world of energy services companies (ESCOs) and real estate portfolio managers eager for a faster and cheaper way to find the low-hanging efficiency fruit amongst a bewildering array of building types, retrofit options, and investment strategies.

 “We collect minimal asset data, and we use that data to do advanced analytics based on tens of thousands of previous energy audits to build energy models and run them against thousands of energy retrofits,” CEO Bennett Fisher said of the company’s approach.

Based on a 20-minute data-crunching process, Retroficiency’s platform can identify a building’s energy characteristics with 90 percent accuracy and make recommendations of a dizzying array of potential projects, complete with the cost and energy and carbon impact of each one, or of many of them added together. The whole process is applied to a customer’s entire portfolio of properties to find the cheapest and fastest way to reach its broader energy, carbon and sustainability goals.

Property management giant Jones Lang LaSalle has been an early customer, and Fisher identified real estate management firms as a key target market. But its recent landing of big government contractor SAIC as a customer, as well as engineering firm Optima Engineering and environmental consultant Linnean Solutions, points to the potential for engineering and consulting firms to use the startup’s technology to speed their own processes as well.

While the big ESCOs in the business can derive a lot of value from that kind of analysis, Pike Research analyst Eric Bloom wondered whether they might not be busy working on auditing and analytics tools of their own.

“Take a Johnson Controls or a Schneider or a Siemens -- they have a huge base of buildings to work off of, and whenever they need data, they have it, compared to these startups that are putting together data upfront,” he said. “I think the big companies will be developing their own approach to this. I’ve already started hearing some rumbles.”

Fisher isn’t discounting the potential challenge, though he noted that ESCOs’ core software expertise tends to lie in supporting their building management systems, rather than in the auditing and data analysis his company has built.

Of course, challenges could come from IT giants like IBM, which has been beefing up its smart buildings portfolio via partnerships with Schneider, Johnson Controls, and Honeywell, as well as its March acquisition of building management technology provider Tririga.

There’s little doubt that making buildings more energy efficient remains one of the fastest and cheapest ways to green a company’s energy profile, so expect more entrants in the field -- and more competition. SCI, Serious Energy, BuildingIQ, and Cimetrics remain interesting names to watch.

But with only a fraction of the 80 billion square feet or so of commercial real estate in the U.S. taking advantage of the full array of energy-saving technologies, there’s certainly plenty of room for competitors to work with each other as well as against one another, Bloom said.

“It’s sort of the Wild West, innovating in the area of energy auditing, energy benchmarking and selecting energy efficiency measures,” he added.