21 Grand St, South Portland, ME is a single family home that contains 1,610 sq ft and was built in 1900. It contains 4 bedrooms and 2 bathrooms. This home last sold for $405,000 in March 2017. The Zestimate for this house is $380,152, which has decreased by $42,983 in the last 30 days. The Rent Zestimate for this home is $2,000/mo. The property tax in 2017 was $4,412. The tax assessment in 2017 was $245,100, an increase of 19.6% over the previous year.