Algonquin, IL Prices for Houses for Sale AVERAGE 417,326 +18% MEDIAN 409,197 +20% Relative Price (per sqft.) PRICE Listings of Algonquin Homes for Purchase ACTIVE 33 -20% NEW 64 -30% Market Duration of Homes Sold DAYS 32 -10% Local Statistics Population 30,730 (0.00%) House Size (sqft.) 2,520 (9.88%)