A planned 50-foot-high office development with a shadow that neighbors said would plunge their home into darkness could receive final approval by the Palo Alto City Council on Monday night, June 1.

The proposed building at 2555 Park Blvd. would tear down an existing 10,800-square-foot two-story office building and build a new 24,466-square-foot three-story building. But Jared and Alice Jacobs, whose Sherman Avenue home is next door, said the Architectural Review Board and the Planning and Transportation Commission erred when they recommended approval of the building, parts of which would be 13 feet higher than the city's 37-foot limit.

The Jacobses and their neighbors, who are also concerned with the project and its traffic impacts, plan to take their concerns to the council in hopes of nixing the project in its current form.

The Jacobses' home is located in a mixed-use neighborhood that includes largely multi-unit housing and offices. Their single-family home was zoned as a "nonconforming use" when it was built in 1990 by a previous owner, they said.

But that fact does not disqualify them from city zoning protections, including rules that require projects to limit sun and shade impacts on abutting properties, they said. The project would darken most of their large first- and second-floor southeast-facing windows, including their kitchen, living room and master bedroom, for most of the year, they said.

"The house has been standing for 25 years, and our residential use has no expiration date," the Jacobses said in an 8-page letter to the Council regarding why their residential rights should be considered.

"If the project is built, our entire rear boundary will face a very close 37-foot concrete wall with a small tree sandwiched in front instead of the immense sky, sunrises and diffuse natural light that we enjoy today," they wrote.

The development is the latest in a series of tugs-of-war between residents in the neighborhood and the city's vision for the district, which would allow for mixed-use, higher-density housing near the Caltrain corridor and more intensive office development to make the area a thriving start-up and tech hub.

Other residents are expected to attend the council meeting tonight to object to the project's traffic impacts, Jared Jacobs said. Park Boulevard, which is an arterial street connecting the California Avenue retail district with Oregon Expressway, has been the subject of parking and traffic-safety concerns among numerous residents.

The city's Architectural Review Board and Planning and Transportation Commission have already voted to support the development, which also has the blessing of the city's planning staff. City planners also recommend granting the developer, Tarlton Properties, the height exception. The extra 13 feet would allow the developer to include in the design two stair towers and a "tensile roof" structure that staff argues would "add a visual element to the building."

The roof structure would be "set back from the edges of the building, to avoid adding to the perceived height and massing and to protect privacy," according to a report from the Department of Planning and Community Environment.

The planning commission also requested that the applicant perform additional analysis on the building's shadow impacts. According to the staff report, the applicant studied shadow impacts at nine times of the day and year and concluded that the structures that increase the building's height "would result in a minimal shade impact on the residential neighbor's home."

From the neighbors' perspective, shadows aren't the only concern. The Jacobses claim that a parking and vehicle-trip analysis for the project underestimated the car queuing to enter the parking area, which would cause a backup on Park Boulevard and negative traffic impacts to California Avenue and the El Camino Real and Page Mill Road intersections.

There is already scarce public parking in the vicinity, and there is a good likelihood that building tenants may choose to fill the available street parking instead of waiting 1 to 2 minutes for the parking machines under the office building, the Jacobses said. The building is also near the proposed police station on Sherman Avenue at the Santa Clara County Superior Court parking lot, which would further tax area traffic and parking, they added.

The City Council meeting takes place at 7 p.m. in Council Chambers, 250 Hamilton Ave.