One of the most reliable sources of fuel for New York’s apartment buildings is gas, but the lines that it flows through — from heating to cooking — have become a critical concern because leaks often lead to complete gas shutdowns. AJ Rexhepi, CEO of Century Management, recounts how one board at a pre-war West Side co-op looked at their fuel options, considered their finances and decided to stick with gas — but not wait for the inevitable. Habitat’s Carol Ott interviews Rexhepi to find out what they did.