For buyers-

Besides the $8,000 first-time home buyer tax credit and the $6,500 move-up credit, there are an array of energy tax credits that can make home improvements pay off in cash. 

http://www.energy.gov/taxbreaks.htm

http://www.energystar.gov/index.cfm?c=tax_credits.tx_index

http://www.energystar.gov/index.cfm?fuseaction=rebate.appliance_rebate

http://dsireusa.org/