The big project that will replace the longtime University Square shopping center has, at least in its conceptual form, a number of impressive features.

As developer Cousins Properties LLC envisions it, 123 West Franklin (not to be confused with 140 West Franklin, the high-rise condo complex under construction directly across the street) will include 300 apartments and more than half a million square feet of restaurants, shops and offices.

It’ll have a public green space larger than Weaver Street Market’s lawn, plus another 18,000 square feet available for recreation. It is posited to bring 11,000 very welcome new jobs to Franklin Street, and it might even include a grocery store, which has been a glaring lack downtown ever since the late lamented Fowler’s, with its beloved walk-in beer cooler, Big Bertha, closed down many years ago.

What 123 West Franklin doesn’t have is any affordable housing. All 300 apartments are to be rented at market rates.

Cousins has offered to contribute $60,000 to the town’s affordable housing fund. Given that 123 West Franklin’s projected tax value is $75 to $100 million ... well, you don’t have to be a math whiz to recognize that that constitutes what Town Council member Ed Harrison called a “microscopic” contribution.

The council would like to see the developer show a somewhat more robust interest in the affordable housing issue when the project comes back before the board in January.

We’d like to see that too. We mention all this, though, not just to wag a finger at this particular development but to highlight the larger problem of affordable rental housing in and around Chapel Hill.

If 123 West Franklin consisted of condos or single-family homes for sale rather than apartments for rent, it would fall under the town’s inclusionary zoning ordinance, which requires developers to set aside 10 to 15 percent of their retail housing at affordable rates.

That’s why, just across the street, 18 of the 140 condos at 140 West are priced to meet the town’s affordability guidelines, with financing handled through the Community Home Trust affordable housing organization.

But under state law, local government can’t regulate rents. Chapel Hill can, and does, “urge” developers of rental projects to include affordable units or pay into the affordable housing fund, but rentals are exempt from the inclusionary zoning ordinance. That ties the town’s hands.

Most of the time, when we talk about affordable housing, we talk about home ownership. But rentals are a key component of the community’s housing environment – more so now than ever, with the economy still in slow recovery and tight lending conditions continuing.

And affordable rentals are essential to the demographic diversity everybody says they want. If we mean what we say – if the waiters, store managers and office staff who will fill most of those 11,000 new jobs at 123 West Franklin are to have any hope of living there, too – we need to explore as many creative, innovative ideas as we can find for leveraging more affordable rental housing.