The Builders Association of the Twin Cities (BATC) is continuing its fight against a new building code that requires an indoor fire sprinkler system in all new, large single-family houses.

The association says the rule, which covers homes with more than 4,500 square feet including unfinished basements, will affect 30 to 40 percent of the homes built in the Twin Cities and add thousands of dollars to the cost of each.

In January, BATC filed a legal petition to the Minnesota Court of Appeals, asking it to review the appropriateness of the sprinkler mandate along with various provisions in an updated energy code. The group has filed its briefs and on Wednesday will make its case before the Minnesota Court of Appeals in St. Paul.

BATC will make the case that the codes have "substantial flaws and that Minnesota Department of Labor and Industry did not properly analyze the impact of the rule."

Those legal briefs have been filed by BATC member Frank Kottschade in partnership with the National Association of Home Builders, the Builders Association of Minnesota and the Minnesota Association of Realtors.

The Court of Appeals is expected to publish their decision two to four months after the oral arguments.

If the builders lose, it will be up to the BATC board of directors to decide whether to make a further appeal to the Minnesota Supreme Court.

In the meantime, the building and energy codes remain in effect.