On Friday, Facebook and Signature Development Group submitted plans to the city of Menlo Park laying out more details for their new Willow Village development, according to a statement from the developer.

The proposed development — slated to be the largest ever in Menlo Park — would replace a 59-acre campus of single-story offices and industrial spaces located at the corner of Willow Road and the Dumbarton rail line with an entirely new neighborhood.

The development would replace the Willow Road office park with 1,729 housing units, 1.25 million square feet of office space, a 193-room hotel, shopping space, including a grocery store, as well as a publicly accessible neighborhood park, elevated park area, dog park and town square.

The new submissions include architectural drawings for all of the new buildings, which reveal a large glass dome planned for use as a collaborative area for Facebook workers, bordered by an elevated, landscaped path that would stretch over Willow Road and connect to the Belle Haven neighborhood. The path is intended to be similar to New York City's High Line, offering easy pedestrian and bike access from Belle Haven across Willow Road and into the development, with publicly accessible views of the Bay.

The number of housing units is higher, while the square footage of the office space is lower than in earlier iterations of the proposal. Those changes were made in response to community input, Michael Ghielmetti, president of Signature Development Group, said in an interview.

Early feedback to the proposal raised community concerns that the large development would worsen traffic and the community's already high ratio of jobs to housing units. Ghielmetti said that his team had heard demand from the Belle Haven community and other residents on Menlo Park's Bay side that a grocery store be built sooner rather than later, and now the plan is to build the grocery store in the first phase of the development. Currently, residents have to cross U.S. Highway 101 to access a full-service grocery store, he noted.

Of the 1,729 housing units, around 320 are intended to be available to households with low incomes. Of those, 120 units are intended to be affordable to very and extremely low-income seniors, according to a press statement.

The development is set to expand employee capacity by 3,400 workers in addition to the existing 3,500 employees who work at the site, nearly doubling the number of workers at the new campus to 6,900, according to developer representatives.

The plan is to use a mass timber construction technique that is considered far more sustainable than the more traditional methods involving concrete and steel, Ghielmetti explained. This method is expected to reduce embodied carbon emissions — the amount of carbon used to produce materials — by 52% and save about 27,800 megatons of carbon dioxide emissions. That is about the equivalent amount of carbon dioxide that is sequestered in a year by 36,000 acres of forest, according to a press statement. Other environmental efforts include adhering to LEED Gold standards, making buildings all-electric, using recycled water, and adding solar power, according to the statement.

One key question, with so many employees working remotely while the pandemic rages, is what the future of Facebook's office presence will look like in Menlo Park.

"I'm assuming they and others will continue to evolve their policies," Ghielmetti, the developer, said of Facebook leaders' current position to permit some employees to work remotely indefinitely. He added that offices are still important for defining company culture, fostering collaboration and helping employees feel a sense of belonging.

This development is notable for its emphasis on the public sphere, he added. While the current site is occupied by industrial buildings, warehouses and single-story offices, the new site would centrally feature a town square and main street where the business, housing and ground-floor retail areas would connect, he added. The sidewalks are planned to be wide, with separated bike lanes that are protected from vehicle traffic.

"It won't feel like an old Silicon Valley campus," he said.

The Facebook buildings would still be secure and accessible only to employees and guests, he noted.

The developer has proposed to build the project in two phases, with the first phase broken down into two sections.

According to documents filed with the city, in phase 1a, the plan is to build 565,000 square feet of the planned office space; the elevated park; 150,000 square feet of retail space, including the grocery store, the hotel, the town square and a parking garage to go with it; another parking garage near the offices; a grade-separated tunnel under Willow Road; 1,050 housing units; and the public-access park and dog park. Phase 1b would include 1.035 million square feet of office space, 50,000 square feet of retail space and an additional parking garage. Phase 2 would add the remaining 679 housing units.

Ghielmetti said that the next steps are for the draft environmental reviews to be completed and released, which is expected to happen around midyear. After that, the team hopes to conduct more public outreach and is aiming to attain final approval for the project by the end of 2021. Planning for about a year for demolition, utility and foundation work, construction on the first phase would be expected to take about 48 months and reach completion in 2025, and the second phase would be developed afterward.