The Sustainable Energy Authority of Ireland (SEAI) said around 1.7 million homes could be eligible for new and increased grants.
They range from €300 (£265m) for attic insulation to €700 (£617) for heating control upgrades to €6,000 (£5,290) for external wall insulation.
From April this year, a new grant of €3,500 (£3,086) will also be available for heat pumps.
The grants typically cover one third of the total cost of the works for an average home, which spends around €1,850 (£1,631) on heating every year, according to the SEAI.
It believes households could save up to €600 (£529) a year on heating bills as a result of energy efficient upgrades.