Twin Cities builders continue to fight against new state rules they say add unnecessary costs to new houses.

The Builders Association of the Twin Cities has filed a petition with the Minnesota Court of Appeals challenging the Department of Labor and Industry's amendments to the state's residential code and energy conservation code. The state is expected to respond in the next few weeks.

Shawn Nelson, a former association executive and president of New Spaces, said the new rules are "the largest regulatory tax on home buyers in Minnesota history" and create a financial burden that exceeds the value of the changes.

The suits follow several years of rule-making that concluded with an agreement between the builders group and state agency on most changes.

But in the energy code, the builders group advocated for performance-based rules it says would be less expensive than the "prescriptive standards" that were adopted.

The association also opposed a sprinkler requirement, which applies only to houses that are 4,500 square-feet (including the basement) and larger, which combined with the energy code could add almost $20,000 to the cost of that home. The building code changes took effect on Saturday. The energy code change takes effect on Feb. 14.