Thirty-five is probably the most important number we have when it comes to the built environment on Block Island. The height of a house is limited to 35 feet. In future weeks, KeepOurPlace.com will deconstruct that height number in greater detail, but for starters assume that houses have nine foot ceilings and that the joists and floorboards that support the next floor up add another foot. So each story of a house uses up ten feet of height. Thus a three-story house is thirty feet plus the roof plus the part of the foundation that sticks out of the ground. It is typically not feasible to build a three story house on Block Island. (The mansard roof design is an obvious exception, since it incorporates a very shallow roof in a way that is consistent with the architecture of the downtown area.)

This brief analysis does, however, point up one of the quandaries that has been debated on the island for years: limits on building height create the temptation to use shallow non-Mansard roofs, where the steeply pitched roof is the tradition on the island. The need, of course, is to keep track of the eave height, the height at which the roof begins, as well as the ultimate height of the ridge pole.

There are also issues at the ground level. Issues like “what is the ground level”? Block Island building sites are rarely flat. Many homes have foundations fully in ground on one side, while fully exposed on the other. The island uses the average of the four corners of the houses. Even that is open to abuse. Unscrupulous owners are known to push dirt up against their foundations in order to get above 35 feet. There have even been cases of regrading entire lots, creating artificial knolls where none existed historically. The standard interpretation of “above ground level” is “above historical grade” which is documented in the USGS topographical survey of the island, but it is not clear if this has ever been tested.