What does a blot look like?
These blots run the gamut from two small lots to four or five, and can take up most of a city block.

For some, the extra space has provided a place to put in a wheelchair ramp or a raised garden bed, or allowed for the planting of trees for privacy. Others have prompted large additions such as a new wing or a move to change the orientation of the house to face away from the street and to a central garden.  

Harris, a yoga instructor, and his partner installed a pool in their backyard, and added Zen-style landscaping, including a large wooden arch, statue of Buddha and groves of bamboo. Harris' half-acre compound has been featured on the Ohio City garden tour four times in the past two decades.

"As a result of our salvaging this house, we have really changed the whole neighborhood," says Harris, 63. "There's a lot of new construction going on. It's hard to believe it's the same neighborhood."

Shelina Gethers, 48, who lives in the historic Gentilly neighborhood in northern New Orleans, has created her own beautiful retreat after purchasing the abandoned corner lot next to her from the city for $4,000 in late 2009. She put a concrete fence around both lots and added a pool and a gazebo, while keeping the mature trees on the lot she acquired.

"It really is a little outside oasis," she says. "When it's hot, my granddaughter is in the pool every day."

The process was easy, she says, despite its nine-month time frame. And because she had such an easy time of it, her neighbor across the street decided to purchase the lot next door to her, and has since added a gazebo and a half-dozen fruit trees, further improving the look of her street.

The problem with blots
Of course, larger lots don't solve the problems that some of these emptied-out neighborhoods have with crime, and they can't replace prime amenities, parks or good schools.  

Gethers, who moved to the neighborhood in the early 1990s when every house was occupied, still doesn't like having a vacant house across the street and empty lots next to her, but she says so far there has been no vandalism or vagrants.

"We would really love to have neighbors" move in there, she says.

Gethers was lucky to have neighbors who are willing to make value-boosting improvements. Without much oversight from the city or neighborhood groups, some side-yard expansions have wound up as car parks or places for people to store their junk, Dewar says.