Jesse and Andrea Ibanez know a thing or two about houses. They are real estate agents with training in sustainable building practices and energy efficiency. So when Andrea developed a constant cough after moving into their house in Pacific Beach, they knew their living environment could be the cause.

"Something did not feel right," Andrea recalls. "I was suspicious that the age and condition of the house may be a factor."

Mark Remy bought his 1960s era San Diego home in 2008 as a fixer-upper. But even after remodeling, with new windows, sliding doors, stucco, ceilings and more, it still wasn't as comfortable as he wanted.

"When I moved into my house, it was like camping out," Mark said. "In the winter, I could see my breath in the morning." He was also concerned about the safety of the natural gas-burning wall heater.

Skip and Sandy Florey of Mira Mesa first learned about home energy upgrades by attending an energy efficiency home tour in 2012. "We wanted to find out what else we could do to save energy and make our home more comfortable," Sandy recalls.

At the tour, they signed up for an energy assessment and discovered their ducts were leaking 30 percent of the conditioned air and their water heater was generating unsafe levels of carbon monoxide.

When Michael and Jessica Wolf bought their 1911-built Craftsman home in the South Park area of San Diego, it came with the original furnace and a lot of air leakage. "The house was very drafty with air coming in through the windows and floors," recalls Michael.

To make the home more comfortable, the couple incorporated energy upgrades into their remodel plans. Improvements included new ducts, air sealing, attic and wall insulation and a tankless water heater. They also had dual-pane windows and ENERGY STAR appliances installed.