Standing in front of the Lennar bandwagon is a coalition of community, environmental, and housing activists who this spring launched a last minute, volunteer-based signature-gathering drive that successfully became Proposition F. It would require that 50 percent of the housing built in the BVHP/Candlestick Point project be affordable to those making less than the area median income of $68,000 for a family of four.

Critics such as Lennar executive Kofi Bonner and Michael Cohen of the mayor's Office of Economic and Workforce Development have called Prop. F a "poison pill" that would doom the Lennar project. But its supporters say the massive scope and vague wording of Prop. G would have exacerbated the city's affordable housing shortfalls.

Prop. F is endorsed by the Sierra Club, People Organized to Win Employment Rights, the League of Conservation Voters, the Chinese Progressive Association, St. Peter's Housing Committee, the Harvey Milk LGBT Democratic Club, Coleman Advocates for Children and Youth, the Grace Tabernacle Community Church, Green Action, Nation of Islam Bay Area, the African Orthodox Church, Jim Queen, and Supervisor Chris Daly.

Cohen criticized the coalition for failing to study whether the 50 percent affordability threshold is feasible. But the fact is that neither measure has been exposed to the same rigors that a measure going through the normal city approval process would undergo. Nonetheless, the Guardian unearthed an evaluation on the impact of Prop. F that Lennar consultant CB Richard Ellis prepared for the mayor's office.

The document, which contains data not included in the Prop. G ballot initiative, helps illuminate the financial assumptions that underpin the public-private partnership the city is contemplating with Lennar, ostensibly in an effort to win community benefits for the BVHP.

CBRE's analysis states that Lennar's Prop. G calls for "slightly over 9,500 units," with nearly 2,400 affordable units (12 percent at 80 percent of area median income and 8 percent at 50 percent AMI), and with the San Francisco Redevelopment Agency "utilizing additional funding to drive these affordability levels even lower."

Noting that Prop. G. yields a "minimally acceptable return" of 17 to 18 percent in profit, CBRE estimates that Prop. F would means "a loss of $500 million in land sales revenue" thanks to the loss of 2,400 market-rate units from the equation. With subsidies of $125,000 allegedly needed to complete each affordable unit, CBRE predicts there would be a further cost of "$300 million to $400 million" to develop the 2,400 additional units of affordable housing prescribed under Prop. F.

Factoring in an additional $500 million loss in tax increments and Mello-Roos bond financing money, CBRE concludes, "the overall impact from [the Prop. F initiative] is a $1.1 to $1.2 billion loss of project revenues ... the very same revenues necessary to fund infrastructure and community improvements."

Yet critics of the Lennar project say that just because it pencils out for the developer doesn't mean it's good for the community, which would be fundamentally and permanently changed by a project of this magnitude. Coleman's Advocates' organizing director Tom Jackson told us his group decided to oppose ...