There’s a reason why city officials have favored housing developments designed for residents of mixed income. There are multiple reasons, in fact, especially where it concerns the redevelopment of the urban core, where Honolulu hopes to narrow the gap in available affordable housing.

One is that the urban core should be home to at least some of those who work there. The biggest need for housing is for units priced at workforce and below-median-income levels, so the city must encourage the placement of such housing as part of Honolulu’s “urban infill” development.

But another reason is that studies show that steering clear of lower-income concentrations has social benefits. Families who live in better surroundings, especially the children in those families, do better than those who remain in a worse neighborhood or cycle downward.

And those children comprise a next generation that will suffer from fewer social ills and, potentially, continue that upward mobility with their own families.

This inclusiveness is not the message that’s transmitted by the design of a proposed condominium high-rise in the Kapiolani Boulevard corridor.

As currently envisioned, the residents in the tower’s market-priced units would enter from Keeaumoku Street. The renters, earning between $58,600 for an individual and $83,700 for a family of four, would come in from the Makaloa Street side.

The rental entrance is a design element now dubbed a “poor door.” It’s good that the City Council is taking a pause on the project, proposed by ProsPac Holdings Group LLC, until this problem can be resolved. Endorsing this idea would set a bad precedent for the other projects planned in this district, which is envisioned as a diverse community.

The legislation, Resolution 17-333, would enable the developer more density, and to build to a greater height than zoning now permits — 400 feet instead of 250. The 41-story project would be constructed on top of a two-story commercial complex.

The resolution would make these allowances because the ProsPac project lies within the transit-oriented development (TOD) zone along the city’s rail alignment. The fact that ProsPac is keeping its allotment of 78 affordable rentals within this development’s footprint, rather than siting them at some distant location, is a necessary element.

Access to rail transit should be available to all residents of these projects seeking TOD benefits.

However, the condominium- rental tower should strive for some community cohesion, and segregating residents to separate entrances is simply unacceptable.

ProsPac Assistant Director William Chen said the original plan was for a common entrance but that it changed when the affordable component of the project was changed to rentals. The separate management and “operational needs” would be better served with the two entrances, Chen said.

It is unclear why even separate sections of the structure need to be completely disconnected, with residents approaching from the direction nearer one door forced to go around the corner. Many complexes have connecting corridors to enable residents to get from one side to the other; the same can be true here.

Officials in other cities have decried the poor-door design. Honolulu might consider following the example of New York in barring separate entrances for affordable units for any developer receiving tax incentives.

The ProsPac project would provide special amenities for the condo owners, too, such as a pool deck, a fitness center and others. Given that the condo maintenance fee supports them, that condo benefit seems fair enough — although access to these could be offered to renters who pay a membership fee, as well.

There should be room for compromise here. But the concept of a poor door, at least, should be shown the exit at City Hall.