As a force on the Erie County Industrial Development Agency, County Executive Chris Collins has approved tax breaks for corporate projects.

Some of Collins’ own companies enjoy tax breaks because they operate in Empire Zones.

But Collins draws the line on tax breaks for homeowners who build additions to their residences.

“Why should taxpayers subsidize the capital improvements of other taxpayers?” Grant Loomis, a Collins spokesman, asked in explaining why the county executive opposes the “residential tax abatement” proposed by Democrats in the County Legislature.

Under the proposal, county government would delay taxing expensive additions — those worth $3,000 to $80,000 — that raise the taxable value of single-family and two-family homes.

So rather than taxing a $25,000 addition as soon as it goes on the tax rolls, the county would exempt the improvement from taxes in the first year.

The county would then remove 20 percent of the exemption a year over the next five years, in effect taking six years to tax the addition at its full value.

In theory, the tax break would encourage investment in neighborhoods, especially in older homes found in Buffalo and its inner-ring suburbs. Other communities are considering similar abatements on their own property taxes.

One of the sponsors, Legislator Robert B. Reynolds of Hamburg, patterned the plan on the tax breaks given companies that expand and create jobs or, in some recent examples, expand with the promise that at least they will not lay off workers.

That reasoning does not impress the county executive.

To balance future budgets, Collins is banking on property values rising by 4 percent a year, and home improvements are a component of that growth. If the abatement takes $50 off the tax bill on a $10,000 capital improvement in its first year, other taxpayers will have to cover the county’s loss, Loomis said.

Collins does not consider payment-in-lieu- of-taxes programs and Empire Zone breaks as legitimate comparisons to residential tax abatements, Loomis said.

PILOTs and Empire Zones are designed to promote “meaningful economic development and job creation, not building an addition on your house,” Loomis said.

But is an addition to one’s house so bad? “Neighborhood development and investing in our older housing stock is economic development. It should not be seen as charitable activity,” said Aaron Bartley, executive director in Buffalo for People United for Sustainable Housing, which seeks to improve impoverished West Side neighborhoods. “It is a core part of the economy. Everything from materials to labor translates to local employment.

“I would also point out,” Bartley said, “that all residential investment can be shown to create incentives for neighbors to invest in their own properties, whether they are getting the abatement or not. So there is an immediate spinoff effect, which over the long term would probably bring more tax dollars into government coffers than without it.”

Allison Duwe is the executive director of the Coalition for Economic Justice, another neighborhood development group involved in the current debate over how to reform industrial development agencies.

“Advancing ways to alleviate the tax burden on low-and middle-income residents while encouraging them to make investments in their homes and thus their neighborhoods is a good thing,” she said. “It is unfortunate that the county executive is pushing back on this type of tax relief while working hard to uphold no-strings-attached tax breaks for business.”

The Democratic proposal, sponsored by Reynolds and Legislator Michele M. Iannello of Kenmore, did well in its first legislative test. Members of the Government Affairs Committee spoke of it approvingly. Legislator Raymond W. Walter, an Amherst Republican, climbed on as a co-sponsor.

Along the way, Collins signaled his opposition. By the time the full Legislature approved the measure in concept, two Republicans — Edward A. Rath III of Amherst and John J. Mills of Orchard Park— were opposed. Unable to climb off, Walter voted in support but said he might not do so again.

“On the surface, it sounds like a great idea,” said Mills, the Legislature’s minority leader who runs a business that has received IDA-sponsored breaks on sales taxes and mortgage taxes in return for the creation of five jobs.

“But on the back side you have to look at the costs and its impact on other taxpayers in the community,” he said. “We are in the middle of a recession. When you put forth a resolution like that, you have to show the people who would be voting for it that it makes sense financially.”

With Collins opposed, the abatement is on life-support. While the full Legislature voted 13-2 to call on the county attorney to write the law, Collins controls the county attorney’s office.

The Democratic majority, furthermore, will shrink next year to nine from 12 members, eliminating the Democrats’ veto-proof majority. The main sponsors, Iannello and Reynolds, were defeated by Collins-backed candidates earlier this month and will leave the Legislature at the end of this year.