The national average cost for building a single townhouse is $111,000 to $222,000, with most people paying around $166,500 for a 1,500 sq. ft. Townhouse Property Building Costs National average cost $166,500 Average range $111,000-$222,000 Minimum cost $77,250 Maximum cost $312,500 Townhouses come in many sizes and styles, and with that comes a range of associated costs. The national average cost for building a single townhouse is $111,000 to $222,000, with most people paying around $166,500 for a 1,500 sq.ft. traditional-style townhouse, fully built. The lowest costs associated with townhouses are around $77,250 for a 750 sq.ft. townhouse with some modular construction, while the highest costs are around $312,500 for a 2,500 sq.ft. luxury townhouse in an urban area.