Somerville Ward 3 Alderman Thomas F. Taylor said he would make good on a promise to bring together the opposing groups that have tussled over a proposed development of 40 units of affordable housing in Union Square. A meeting organized by Taylor is slated for 6:30 p.m. July 11 at the Argenziano School at Lincoln Park. The five-story, $15 million development, proposed by the Somerville Community Corporation, would feature housing for working families, include retail space on the ground floor, and replace the former Somerville Boys & Girls Club. A resident group, Union Square Rising, has emerged to oppose it, however, saying the building’s scope and design are out of character with the neighborhood, and that the developers are ignoring their requests for compromise. The SCC contends it seeks only to build more affordable units in the city before opportunities dry up. Union Square Rising founder Zac Zasloff said he hopes the meeting will be a constructive venue for his group to make their pitch, an opportunity he said was not afforded at previous community meetings.