San Francisco came one step closer Wednesday to replacing the 22-year-old forest green JCDecaux public toilets and advertising kiosks that dot the city.

The six members of the Historic Preservation Commission present voted unanimously to approve sleek new designs by SmithGroupJJR, a local architecture firm.

There are 25 public toilets and 114 kiosks scattered across the city, with six toilets and 34 kiosks located in historic landmark or conservation districts.

In three locations — Civic Center Plaza, the cable car turnaround at Powell and Market streets, and UN Plaza — the current single public toilets will become double toilets, with one stall compliant with the Americans with Disabilities Act. The size of the double commodes caused some concern among commissioners because they would be substantially bigger than the existing structures, while others saw reason for them.

“I have observed that in San Francisco, currently, there are a great many full bladders and that to me is complete justification,” commissioner Richard Johns said.

Designers at SmithGroupJJR made improvements to previous mock-ups, stemming from comments they received at a July joint meeting between the Historic Preservation and Arts commissions. In response to comments from commissioners about glare and graffiti, the designers settled on a new surface that has a matte, dimpled texture.

The new toilet designs incorporate skylights in case the lights inside go out during the day, a concern with the current structures.

The group also rolled out several kiosk designs: a regular kiosk with advertising and public service announcement space, a retail and vending kiosk, and an interactive kiosk.

The current toilets and kiosks are modeled after Parisian fixtures and were installed in 1996 by French firm JCDecaux. When the 20-year contract came to a close, JCDecaux offered new designs, all of which were rejected by the Department of Public Works. San Francisco architecture firm SmithGroupJJR won the opportunity to design the new structures.

If the San Francisco Arts Commission approves the design in November, the proposal will go to the Board of Supervisors and Mayor London Breed for final approval.

Ashley McBride is a San Francisco Chronicle staff writer. Email: ashley.mcbride@sfchronicle.com Twitter: @ashleynmcb