The festival that took over Mitchell Park Community Center in Palo Alto on Saturday featured no music but plenty of musings, maps and moments of healthy tension.

Billed as "The Summit" and likened to a local Constitutional Convention, Palo Alto's all-day Planapalooza featured three acts, five stages (aka community rooms), a scattering of outdoor booths and about 300 residents, divided into dozens of groups, debating what the city should look like in 2030. Over the course of seven hours, participants grappled with some of the most contentious questions of the day: Which impacts of growth concern you the most? Where should new housing be built? How should the city's main transportation corridors function 15 years from now?

It took the city nearly a decade to get to Saturday's summit, a milestone in Palo Alto's update of its land-use bible, the Comprehensive Plan. The City Council decided in 2006 that it was time to update the voluminous plan, on which theoretically most council decisions are based, and the effort has sputtered in fits and starts ever since. Now, the new council is committed to completing the revision by mid-2016, and the summit was officials' way to gain the citizenry's thoughts about office growth, transportation and housing.

It was also the city's attempt to find some consensus about growth after two deeply divisive election seasons: the 2013 referendum in which Palo Alto voters overturned a council-approved development that included market-rate homes and apartments for low-income seniors and a 2014 election that gave rise to the slow-growth "residentialist" majority on the council.

Both sides in the growth debate turned out in great numbers for the summit, where they were joined by members of the City Council, the Planning and Transportation Commission and various other boards and commissions. Members of Palo Altans for Sensible Zoning, a citizens group with slow-growth leanings, commingled with their counterparts from Palo Alto Forward, which advocates for more housing and transportation options. All participants watched videos highlighting recent demographic, job, growth and transportation trends and then, in small groups, debated the questions posed by staff.

Mayor Karen Holman, who addressed the crowd at the beginning of the summit, declared that the day was "a day when we listen to you."

"Today we hope we will build confidence in our ability to work together as a community, to work together for the future of our town," Holman said.

One topic on which there was no consensus was how to manage the growth of office space. Participants considered three different options: a hard cap on how much new office development should be allowed; a metering mechanism for commercial development to ensure too much doesn't get built at once; and a requirement that developers offset the negative impacts of their buildings.

Each group of four to six people debated the questions posed by staff and texted its two best solutions to a phone number provided. The dozens of texts, which were displayed on projectors in all the rooms, will be displayed on the city's website early next week. The plan is to use this feedback to update the Comprehensive Plan.

When it came to office growth, just about everyone agreed that the city's three-to-one jobs housing imbalance (there are three jobs in the city for every employed resident) is problematic and should be addressed. Yet as their texts indicated, most people weren't too keen on freezing commercial development altogether, or even capping it. While one group texted, "Stop building offices," most other groups said they favored the "offset" strategy, in which office growth is allowed as long as it provides amenities and mitigates potential problems. One group texted, "Growth should be MANAGED not STOPPED." Another wrote, "Better define and enforce mitigations." A third wrote, "Allow new development only if impacts are mitigated" and it includes amenities such as housing, parks and proximity to transit. "Meter and offset growth focused on traffic congestion," contributed a fourth group.

The question of growth management will be one of the most critical and complex topics evaluated in the new Comprehensive Plan. Charlie Knox, a consultant with the firm Placeworks, which is assisting with the Comprehensive Plan update, said the level of rapid growth that the city is now experiencing was preordained in the 1980s. It's only now that market forces are driving developers to build up to the allowed zoning.

"We're really catching up with the capacity that's been in the Comprehensive Plan the whole time, and the market is so strong that we're now filling it," Knox said.

Participants seemed more amenable to growth when it came to housing. The city's 50-foot height limit has long been considered a "sacred cow" of restrictions by those with a residentialist bent, but many participants at Saturday's summit said the limit should be relaxed for housing (though not for offices). "Raise height limits when the results are better for the city and residents," stated one group's text. Another group favored allowing higher density for housing built in mixed-use neighborhoods and near transit. One group called for an "80-foot (height) limit for dense housing," while another supported building two new developments akin to Channing House, a 10-story housing development for seniors.

Not everyone felt that way. One group called for the city to simply "ignore" state mandates that the city plan for more housing.

While some groups thought big when it comes to housing, others thought small. The idea of encouraging more studios and "microhousing" units proved popular, as did the easing of restrictions for single-family residences whose owners want to add a "granny" unit.

As for the locations for new housing, many favored sites in dense areas near transit, most notably downtown and California Avenue. One group, which included Palo Alto Forward member Mila Zelkha and Palo Alto Neighborhoods co-chair Sheri Furman, favored buildings with housing on upper floors and retail on the ground level, much like on Piedmont Avenue in Oakland or in Noe Valley in San Francisco. Their group also favored strengthening the retail sector and increasing ground-floor retail.

Not everyone was thrilled about these exercises. University South resident Elaine Meyer objected to the question about where the new housing should be built, deeming it to be presumptuous. In another group, a resident brought up the idea of building to greater heights and bemoaned the fact that in the current political climate people are saying "no" to all growth. His table-mate responded, "I favor no growth, but not enough people feel this way." The conversation quickly drifted to another topic.

There was more agreement when it came to transportation, with many favoring more shuttles, a doubling of Caltrain capacity and separating the train tracks vertically from the roadways (some people were more specific and advocated for a train tunnel). One group suggested giving subsidized Eco Passes to car-free households, which would be funded by a fee paid by car owners. Another suggested that the city's shuttle service cover a greater geographic area so that there would be a stop within 10 minutes of all households.

One group suggested providing public transportation on "feeder streets" like Alma Street and Park Boulevard, while another suggested pursuing the "Grand Boulevard Initiative" plan for El Camino Real, including a Bus Rapid Transit system and a dedicated bike lane.

City Manager James Keene said it's fitting that the Saturday exercise took place in the new Mitchell Park Community Center, which opened late last year after more than two years of delays and a protracted dispute with the contractor. It was a "tortuous journey" to construct the new center, but now that it's open, it is widely used and widely recognized as a "beautiful place," Keene said.

"We're hoping this is where we end up on our Comprehensive Plan update," Keene said.

Once updated, the new document will have a horizon date of 2030. If things go as planned, the document would be adopted by the council in the middle of next year.