The inspiration of the dwelling of the future—fitted with all kinds of high end, clean energy features and gadgets—is an appealing idea. Unfortunately, many of us have houses that are stuck squarely in the past. To do something like add solar cells, or even just insulate better, requires what can be an tremendous cash outlay. But there’s an upside: If you’re improving your house to be more energy efficient, you’re likely going to start saving funds on the life cycle costs. Are you going to save enough to make your expenditures worthwhile? Should you throw down for that retrofit? The truth is, it depends on what you want to do, and—more importantly—how long you’re going to stay in your house. If you’re just passing through, consider efficient shower heads (paid off in less than a year with it’s $200 of savings) or a programmable thermostat (just a hair over six months). For the more sedentary among us, there are projects that will take longer, such as solar panels (11 years to recuperate the investment) or radiant floors that distribute heat and reduce costs (7 years). But what’s good to remember is that once you make it past the break-even point, you’re saving money every year, cash that goes right into your pocket. In the case of solar power, you might even start making money, as you can supply energy back into the grid. Over 20 years, you’re going to save up to $50,000 in electricity costs with solar panels; up to $10,000 with radiant floors. Think long-term, and these improvements start seeming better and better.