A good place to start when spending money to increase energy efficiency is the crawl space, Duszynski said. ???Many of the crawl spaces were not insulated properly when they were built in the ???70s and ???80s,??? Duszynski said. ???Back then when fuel oil was cheap, you didn???t need much insulation.??? Duszynski said alternative energy systems, such as wind and solar, take too long to recuperate