Walter, a single taxpayer, purchased a limited partnership interest in a tax shelter in 1993. He also acquired a rental house in 2021, which he actively manages. During 2021, Walter's share of the partnership's losses was $11,500, and his rental house generated $48,500 in losses. Walter's modified adjusted gross income before passive losses is $130,500. Calculate the amount of Walter's allowable loss for rental house activities for 2021.