CHASKA — A family has been staying in a hotel for nearly three months, after they could no longer live in their brand-new home, worth about $500,000 and located in one of Chaska’s newest neighborhoods. In July, the company that built the home, Lennar Builders, gave the family a notice it may have had joists that were emitting high levels of formaldehyde. …In fact, four people, who own new homes in Carver, Shakopee and Savage, filed a class-action lawsuit against Weyerhaeuser Co., the firm responsible for producing the lumber, according to a complaint filed in U.S. Federal District court. The plaintiffs, who do not include the Lamberts, are suing for $5 million. “Weyerhaeuser is paying for remediation,” according to Andrew Siegel, a public relations representative for the company in a phone call.