By Jim Levin

A few years ago, one abandoned rowhouse on the 1400 block of North Conestoga Street in West Philadelphia menaced the entire block. Neighbors on the street of 25 brick homes worked hard to maintain their own houses, but could do little about the eyesore in their midst, and the city had been unable to locate the owners to make them meet their responsibilities.

One next-door neighbor hung a blind between his porch and that of the crumbling structure to shut out the sight of its sagging roof, tin-covered door and broken windows. The blind helped him enjoy his flower garden more, but it couldn't block out the threat of sinking property values.

In 2010, the Inquirer described the house as a rotting tooth that threatened the health of the whole block. "None of these houses," said a neighbor, "were built to stand alone."

That could be the motto of the West Philadelphia Scattered Site Model, the philosophy used to complete scattered-site rehabilitation of 1,100 units of affordable rental housing in 900 different locations over the past 27 years.

It is no surprise that a recent study determined that scattered-site rehabilitation units improved the home sale values of the 2½ blocks surrounding each rehabbed home by 50 percent over locations without such projects. That's twice as much as the improvement registered in the neighborhoods surrounding apartment or multi-townhouse developments built on a single or adjacent sites. The study also found that scattered-site projects also cost less to build and used less taxpayer money.

Coincidentally, we acquired and rehabilitated the house on North Conestoga in 2010 along with 59 other abandoned, blighted houses. The house was gutted and rebuilt using sustainable building practices so that it now is home to a low-income family that benefits from living in an affordable, healthy, energy-efficient house in a great neighborhood. If you visited the street, you wouldn't be able to tell this home from its well-maintained neighbors.

The findings of the study by May 8 Consulting and the Reinvestment Fund, a local think tank, have significant policy implications as Philadelphia continues to confront a crisis in affordable housing and neighborhood blight.

The study illustrates why scattered-site rehabs are a good investment, not only for private investors but also for the taxpayers. The study found that 20 scattered-site units have the same positive impact on the surrounding neighborhood as a 40-unit single-site development. The difference in the quality of life that one rehab made on that single block of Conestoga Street can be multiplied by the 59 other houses we gave a second life to in that neighborhood. All told, these efforts increased property values, reduced maintenance costs, and increased property tax revenue for the cash-strapped city and school district.

The study also found that scattered-site rehab units cost as much as 27 percent less than single-site affordable developments, with the cost per bedroom as much as 32 percent lower.

In addition, the study found that scattered-site units required 41 percent fewer Low Income Housing Tax Credits (LIHTC) than single-site affordable developments and did not require any public subsidies. Nearly all single-site affordable housing projects required federal or community development grants, or other forms of publicly financed debt - sometimes as high as 52 percent, in addition to their allocation of LIHTCs to fund their development.

Previous studies of scattered-site developments have shown that tenants become part of the neighborhood community rather than being isolated in an apartment house or low-income development, a benefit for the entire household, especially the children. Being a part of the community provides a strong incentive to develop the skills needed to responsibly care for their homes, and that is better for everyone.

Scattered-site rehabilitation is not without problems. It requires a more nimble approach because it depends on existing housing stock that differs in age and building materials.

At the same time, it makes a striking difference in revitalizing a community. Just ask the residents on North Conestoga Street.

Developer Jim Levin is a principal of WPRE and Neighborhood Restoration, two firms that have employed the scattered-site rehabilitation model in West Philadelphia.