Highlands was made up of 35 subdivisions with the street names, directions and lot sizes not conforming to the Denver norm. As a general rule, building was permitted on lots, and some builders would put up a row of small gothic cottages, built very close together, and surrounded by acres of vacant lots. Any block, in Jefferson Park today, may have houses representing the architecture of the 1890s, 1910s, 1920s 1940s, and 1950s. After the building boom that occurred following the end of World War II, there was very little vacant property left in North Denver.