A half-measure to increase house insulation standards is better than none, according to the Government.

The Residential Tenancies Amendment Bill passed its second reading last night, requiring all rental homes to have a smoke alarm, and a minimum level of insulation.

Housing Minister Nick Smith admits they could have increased the insulation standards further, but says when the costs and benefits are compared, it doesn't stack up.

He said the cost would only be passed on to tenants, which would be particularly unfair for struggling families.

But Green Party co-leader Metiria Turei said the Government's still setting the bar too low.

"We could save lives by simply saying that we want our families to live in homes that are built for the 21st century, not for 1978."