San Francisco Mayor Ed Lee wants to help you buy your first home.

So much so, in fact, that the city is now willing to lend certain first-time home buyers up to $200,000 toward the down payment on their first house or condominium in San Francisco.

That's real money, but in a city where the median sales price was $925,000 in February, is $200,000 enough to make a difference to low-income and middle-class residents being priced out of the city by the tech boom?

"Our city's middle class is deeply affected by the housing crunch - they make too much to qualify for our traditional affordable housing, but not enough to afford much of the new market-rate construction," Lee said recently in announcing his plan to double the down-payment help.

Housing officials say Lee's decision to double the maximum amount for which residents can qualify - and double the annual contribution that money is drawn from to $2 million - is a big step in the right direction. The loans don't need to be repaid until a borrower sells or refinances.

"It's going to be lot more helpful than $100,000," said Olson Lee, director of the Mayor's Office of Housing, citing the previous maximum down-payment help.

The new limit, which goes into effect this month, will allow some home buyers to afford homes costing $600,000 to $700,000, which isn't nearly enough for a home in high-end neighborhoods such as Russian Hill or Pacific Heights but offers options in more distant parts of the city like the Portola, Visitacion Valley and the Bayview, real estate listings show.

Hidden gems

And fixer-uppers or similar gems can be found in surprising places, said Olson Lee, who is not related to the mayor.

"The aggregate numbers (on housing prices) hide that there are units that have old kitchens that haven't been gussied up with the marble and Viking ranges," Olson Lee said. "And they're in different parts of the city."

Melissa deKelaita, 29 and an administrative professional in finance, was able to use the Down Payment Assistance Loan Program to buy a small condo on the border of Pacific Heights and Lower Pacific Heights in 2012.

"I was actually just trying to rent, really," deKelaita said. "The rental market is so insane, I was kind of just, why not (buy)?"

$52,200 down payment

DeKelaita's real estate broker told her about the city's down-payment program, and she was able to qualify for $52,200 to put down, with some of her own money, on a $354,000 junior one-bedroom condo.

"I was able to achieve and do something that I never thought I'd be able to do at this point in my life by myself," deKelaita said. "It gives people a great opportunity to do that type of thing."

The program provides down-payment help in the form of a loan to first-time buyers of market-rate homes who make up to 120 percent of the area's median income - currently $116,500 for a family of four. The city runs similar programs for people buying below-market-rate homes and for others such as police officers and firefighters.

When the homeowner sells or refinances, the loan has to be paid off along with a percentage of the property's appreciation, depending on how much of the purchase price the city covered.

"That's one of the greatest attributes of this," Olson Lee said. "The homeowners ... only pay a share of the appreciation. It's much more equitable."

That money is then returned to the loan pool, which has provided $14.7 million in loans since the program started in 1998, according to the Mayor's Office of Housing. Over that 15-year period, $12.4 million in loan repayments and appreciation have flowed back into the fund.

Ed Lee has proposed that $15 million in new contributions from the city's main spending account be added to the program over five years. The city put $1 million of that into the program in the current fiscal year and has $2 million budgeted for the fiscal year starting July 1.

Program's requirements

All applicants must complete a first-time homeowners' workshop and contribute at least 5 percent of the sales price to the down payment. Their housing costs can't exceed 40 percent of their income. Tenancies in common, a form of ownership similar to a co-op in which multiple residents own a property together, do not qualify.

More than 570 households received down-payment loans between 1998 and 2013, and many more are eager to participate, said Nobby Cheng, director for single-family housing programs at Asian Inc., a nonprofit that provides homeownership workshops. "Most of them have some savings, but not enough to buy a house," Cheng said. "Now this gives them a better chance to buy a house over $600,000. ... They at least will have some more access."

What you can buy with some help from the city Mayor Ed Lee's recent expansion of the Down Payment Assistance Loan Program allows first-time home buyers to get up to $200,000 to put down on a house or condominium. The amount varies based on income and family size. Because condominium homeowner association fees are added to the purchase price when determining affordability, purchasers of single-family homes can qualify for slightly higher-priced properties. Condo Here's an example of what a family of four could buy in a condominium if they met the criteria to receive the $200,000 maximum assistance. Annual household income: $97,100 Buyer's down payment: $31,750 Down-payment assistance: $200,000 Interest rate: 4.25 percent (30-year fixed mortgage) Monthly mortgage payment: About $2,038 Purchase price: $635,000 House Here's an example of what a family of four could buy in a single-family home if they met the criteria to receive the $200,000 maximum assistance. Annual household income: $97,100 Buyer's down payment: $35,500 Down-payment assistance: $200,000 Interest rate: 4.25 percent (30-year fixed mortgage) Monthly mortgage payment: About $2,395 Purchase price: $710,000 Some Listings Some of the options in San Francisco at that price range: $669,000: A four-bedroom, two-bath, 2,626-square-foot home with granite countertops and modern kitchen appliances at the northern edge of Visitacion Valley. 1057 Goettingen St. $625,000: A three-bedroom, two-bath, 850-square-foot home with a deck, a yard and dated appliances in Ingleside Heights. 26 Shields St. $620,000: A three-bedroom, two-bath, 1,675-square-foot home with some dated appliances and fixtures in the Portola. 514 Goettingen St. $599,000: A three-bedroom, one-bath, 1,250-square-foot home with granite counters and stainless-steel kitchen appliances in the Excelsior. 206 Lisbon St. More information on how to qualify for the program can be found through the Mayor's Office of Housing and Community Development: http://bit.ly/1gyeTij Sources: Mayor's Office of Housing and Community Development, Trulia, Chronicle research

John Coté is a San Francisco Chronicle staff writer. E-mail: jcote@sfchronicle.com Twitter: @johnwcote