The Mountain View City Council happily threw its support behind plans to build 62 new affordable apartments in the Jackson Park neighborhood -- but they won't come cheap. At an estimated cost of $38.8 million, the project at 460 N. Shoreline Boulevard would be the most expensive affordable housing project, per-unit, ever undertaken in Mountain View.

Despite the price tag, council members at the Jan. 30 meeting swiftly approved the project in a unanimous vote.

The new housing would be an expansion of the existing 120-unit Shorebreeze Apartments. For about 30 years, Shorebreeze has been managed by MidPen Housing, one of Northern California's largest affordable housing nonprofits. Given the soaring costs of land and construction, it made sense to add density to already established properties, said Peter Villareal, MidPen's housing development director.

"We're trying to find an opportunity to leverage a great location at a low market cost," he said. "It's so hard to find affordable land in Mountain View, but we have to make sure we're finding ways to build affordable housing for families."

To that end, MidPen's proposal calls for demolishing 12 existing apartments and replacing them with 62 new units. All of the displaced tenants would have access to temporary housing, and the option to receive one of the new units when they're finished.

The most complex facet of the Shorebreeze expansion was its arcane financing plan. The $38.8 million project needed to draw from a variety of sources, including nearly $14 million in federal tax credits and about $14 million more in federal loans.

On top of that, the original housing package also requested to borrowing $6.3 million from the city of Mountain View. Ahead of the Tuesday meeting, MidPen officials informed the city they needed to increase that loan to $7.32 million to accommodate rising market costs. Exact details on how that loan would be repaid will be sorted out in negotiations led by the city manager's office.

Each apartment unit will cost about $626,000 to construct, making it the city's most expensive affordable housing built to date. Palo Alto Housing's 62-unit project that is currently under construction at 1701 W. El Camino Real is costing about $424,000 per unit, according to city reports. Meanwhile, a 116-unit ROEM project now being built at 779 E. Evelyn Ave ended up costing about $538,000 per apartment.

Once built, the new apartments are expected to be priced at about 50 percent of the going market rate, but some further subsidies will be available for extremely low-income families, according to MidPen officials. Of the 62 new units, 32 will go to households with Section 8 vouchers. The remaining units will go to eligible tenants based on the city's preference for those who already live or work in the city.

Going forward, the schedule for the project calls for finalizing the financing by late 2018 and beginning construction by the end of the year. In all goes well, the project should be finished and occupied by late 2019.

"It's always an exciting day when we get to vote to add more affordable housing in Mountain View," said Councilman Ken Rosenberg.