Freshman City Councilman Allan Domb offered two proposals Thursday that would add twists to Philadelphia's 10-year tax abatement on new construction and building improvements.

The first would require businesses that get the abatement to use the Philadelphia Gas Works for heating. The second would double to 20 years the abatement for properties valued at $250,000 or less, to spur development in neighborhoods where the incentive hasn't taken off.

"We want to give them a better benefit than everyone else is getting and help their neighborhoods even more," said Domb, a real estate developer known as Philadelphia's "Condo King."

Both bills, if enacted, would need General Assembly approval to take effect. State Rep. John Taylor, chairman of the city Republican Committee, said he had talked with Domb and would consider sponsoring the legislation.

Taylor said the PGW bill could be a hard sell because legislators might worry about steering all users to one utility. But he said the other bill intrigued him, "and I'm going to certainly look at it and see if we can help enable him to pass that."

The bill to double the abatement would apply to residential properties; the one pertaining to PGW would cover commercial and industrial as well. It makes an exception for owners who use more sustainable forms of energy or have financial hardships.

Domb estimated it could bring $2 million to $4 million annually to PGW and build the utility's asset value. "If we as a city are giving an abatement, we'd like you to use our utility company," he said.

Also Thursday, Council President Darrell L. Clarke introduced a bill to ban the city from contracting with firms that merge with foreign companies and move their headquarters overseas - on paper - to avoid U.S. taxes.

Clarke said his interest in the practice, known as corporate inversion, arose when he learned of such a firm seeking Philadelphia Housing Authority (PHA) business. While Council has no control over PHA, Clarke said he wants to make sure no such firms get work through his recently announced plan to retrofit city buildings for energy efficiency.

"We just don't think it's fair," Clarke said. "They're taking advantage of a loophole in the system."

Council leaders on Thursday also called for another energy initiative - installing solar panels on city schools. The effort came as a statewide advocacy group, PennEnvironment, released a report showing the district could cover nearly 40 percent of its annual electricity needs with solar panels.

Councilman Derek S. Green introduced a resolution calling for hearings on putting solar panels on schools.

tnadolny@phillynews.com

215-854-2730 @TriciaNadolny