software companies, and Lowe’s, obviously, is the world’s second-largest home-improvement retail chain. What interests this motley crew is Recurve’s potentially revolutionary business proposition, which I would put this way: 1) Improving home energy efficiency is one of the keys to confronting climate change and volatile energy costs. 2) “Building science” has reached the stage where it’s possible to accurately model the energy flowing into and out of a home. 3) Nobody has yet systematically applied this science through software.
“From an engineering standpoint, we have all the answers,” says Golden. “But they’re stuck in white papers over at Lawrence Berkeley Laboratory, with no business model. A bunch of scientists running around working with a bunch of greenies in Marin has exactly zero impact if you can’t get this into every home in America.”
If you’ve ever had a utility representative come by your home to do an “energy audit,” you know that the usual procedure is to poke around looking for a few leaky windows or ducts. To understand what Recurve’s technicians do, you have to start by abandoning that picture completely. “These aren’t clipboard audits,” says Golden. “This is performance-testing a building.”
For each room and duct, Recurve hooks up blowers that force air through, and measures where the air is escaping. Auditors walk through the house with wireless tablet PCs running Recurve’s Web-based software and note the thickness and construction type for each wall, floor, and ceiling; the types of insulation, furnace, AC equipment, water heater, and major appliances installed; where moisture and mold might be accumulating and where carbon monoxide might leaking, and the like. All that data generates two products: a physics model of the house and how it processes energy hour by hour, and a set of predictions for energy savings if a number of standard improvements are implemented (better insulation, new ductwork, correctly sized heating and ventilation equipment, high-efficiency lighting, and so forth).
Golden calls Recurve’s energy audits a form of mass customization: adapting known building science to each homeowner’s unique structure. The software’s reports make it easy for auditors to figure out what needs to be done and how much it will cost, and equally easy for clients to decide to pull the trigger.
“When you are moving from a cottage industry to a standardized industry, you need to make sure people are all doing the same thing, and you need data very quickly to help convince the customer,” Golden says. “We found that most people in this industry are spending three or four hours on site and another six or seven hours in the office typing the data back in and doing simulations. We give a sales-ready report to the consumer on site. All the great modeling technology in the world, if nobody actually does the changes, is irrelevant.”
Across six years of testing and iterating—with new releases of the software coming almost every week—the company has also reduced errors in its estimates to a minimum. That’s a necessity when
