balustrade vs rowhouse

balustrade

noun
  • A row of balusters topped by a rail, serving as an open parapet, as along the edge of a balcony, terrace, bridge, staircase, or the eaves of a building. 

rowhouse

noun
  • One of a row of houses situated side by side and sharing a common wall. 

How often have the words balustrade and rowhouse occurred in a corpus of books? (source: Google Ngram Viewer )