The two stars agreed to be part of U.S. reality TV show Design Star Hollywood, where real experts compete to redecorate celebrity homes with a budget of $20,000 (GBP13,300).
In the penultimate episode of the current series, which airs on 6 September (09), the designers create a guest bedroom for Thiessen and a baby nursery for Priestley, who became a father again last month (Jul09).