For his speculative housing, Baldwin devised shallow elevations that gave an impression of expensive surface detail but were relatively cheap to construct.

Today 92% of its nearly 600 buildings are 19th-century rowhouses in different architectural styles, predominantly Italianate, many built as speculative housing for the city's middle class.

The oldest rowhouses along the street, the three buildings between 65 and 75, were part of a group of six built as speculative housing by local landowner Thomas Ludlow in 1845.

Owen P. Parsons (22 July 1872 - 1944) was an English architect who designed both speculative housing for rent and larger private commissions.

They are multi-story concrete residential buildings built as speculative housing for Italian immigrant families.

"But the simple fact is that because of the economic conditions, there's no market for this type of speculative housing."

Builder Henry Armstrong erected the original row of 11 on the property as speculative housing the next year, 1861.

Although the "Mr. Potato Head" approach is unusual, the Pearl development joins a small but growing roster of speculative housing designed by major architects.

Occasionally the associations constructed speculative housing.

Half are designated for speculative housing and half for custom housing, said Eileen Beattie, the assistant town planner.