Richard Jones, deputy executive director at the International Energy Agency, addressed a delegation in Fukushima City to mark the first anniversary of the magnitude-9 earthquake and tsunami.
Jones said planning for so-called smart policies would help the region lower energy demands through an integrated approach to wind, solar and other renewable energy sources.
"By using careful planning to rebuild your communities and modern technology and you will make them smarter and more livable than ever before," Jones said.
"As you turn them into models for a new Japan, you will turn the tragedy that has befallen you into a great opportunity for yourselves and the world."
The IEA said buildings in so-called smart communities use about half of the energy of the average U.S. household and about one-third of the average European household.
The earthquake in tsunami that struck Japan in March 2011 crippled the Fukushima Daiichi nuclear power plant. Japanese officials had said the country should embrace a policy that seeks solutions from the tragedy.