All four buildings are slated for occupancy by 2013.
In a smaller but related project with quicker impact, air conditioning will be installed in many Gunn classrooms over the summer and should be nearly or fully operational by fall.
The summer groundbreakings represent about one-fifth of the spending under the $378 million facilities bond, which was backed by 77.5 percent of school-district voters in June 2008.
The stated goal of the measure was to "expand, upgrade and improve" all 17 of the district's campuses, extending their useful lives and accommodating enrollment growth.
Measured against today's enrollment, the facilities bond will create capacity for a 16 percent boost in elementary enrollment, a 9 percent increase in middle school enrollment and a nearly 26 percent rise in high school enrollment, according to target numbers provided by the school district.
The massive program of more than 30 individual projects has been planned and managed by site-based committees of parents and staff in collaboration with school-district officials, architects and building contractors.
The school district's co-chief business official, Bob Golton, is the major coordinator. The entire bond program is overseen by a Citizens' Oversight Committee, which issues annual reports.
Aside from the high schools, major construction has occurred or is planned for all three middle school campuses as well as for Ohlone, Fairmeadow and Duveneck elementary schools.
New, two-story classroom buildings — almost unheard of in Palo Alto until now — are a major feature of the bond projects.
Such a building is midway through construction at Ohlone — slated for occupancy in January — and also is planned for Fairmeadow, Duveneck and JLS Middle School, as well as the two high schools.
Beyond that, Superintendent Kevin Skelly next month is expected to propose locations for an additional 30 new elementary classrooms across the district.
Palo Alto has experienced an unexpected boom in elementary-age enrollment in the past two years that many believe could continue.
Skelly has said the district must prepare itself to handle as many as 568 additional K-5 students in the next five years — the size of a large elementary school.
Besides the groundbreakings expected this summer, several large bond projects — including Gunn's industrial arts building and Paly's softball and baseball fields — already have been completed.
And there's more to come, including a new performing arts center at Paly budgeted for nearly $18 million.
The bond also has funded interactive Smartboards and amplification systems in all elementary classrooms as well as at JLS — more than 200 classrooms in all, officials said.
"We've essentially stopped buying televisions because the (Smartboard) projector will project whatever image you have on your computer screen to the whiteboard," Golton said.
"This is what children are used to doing nowadays."
Bond funds also are supplying classroom technology, including laptops and iPads.
"We're buying more laptops instead of desktops, and now the use of laptops is eroding because people are buying iPads," Golton said.
"All schools are being touched by this. You can't go any place in any of our schools and not find student workstations being funded by our bond."
"Site committees at each campus — including parents, staff and students — have been involved in planning the changes and advertising the plans to school neighbors. A landscape committee populated by community members also has provided scrutiny, particularly of the high school landscape plans.
Elements of the bond program have come before the school board in hundreds of bits and pieces as they make their way through a lengthy approval process, which includes a mandatory review by the Division of State Architect that can take up to nine months.
The recession led to "steeply discounted" bids early in the bond program as contractors slashed their margins to get the work, said Thomas Hodges, a senior vice-president of O'Connor Construction Management Inc. and program director for the bond project.
As materials costs began increasing six months ago, "We're still getting bids under budget, but not the steeply discounted bids we were seeing last year," Hodges said.
This story contains 717 words.
Stories older than 90 days are available only to subscribing members. Please help sustain quality local journalism by becoming a subscribing member today.
If you are already a subscriber, please log in so you can continue to enjoy unlimited access to stories and archives. Subscriptions start at $5 per month and may be cancelled at any time.