The owner of a Somerville business park has proposed a $3.3B redevelopment to attract "tough tech" tenants.

Rafi Properties plans to transform the Somernova complex, a 7.4-acre site of low-slung buildings, into a 1.9M SF, five-building campus with heights ranging from nine to 16 stories, Cambridge Day first reported. The project will produce 1.4M SF of commercial space, 68K SF of retail, 36K SF of community services and 4K SF reserved for the arts.

Rafi also proposed three underground parking lots totaling 1,252 spaces. The development would span four blocks and be built in four phases.

"Our proposal integrates a diverse range of uses, financial models, and strategic alignments carefully crafted to cater to your specific requirements, while simultaneously fostering the growth of startups and the broader innovation economy in the region," Rafi Managing Partner Collin Yip wrote in a letter introducing the project's master plan.

In the years since Rafi acquired the business park in 2018, Somernova has attracted a variety of tenants, including climate tech startup Greentown Labs and MIT venture-backed The Engine.

To build on its tenant base, Rafi wants to "support the needs of the youth and the greater community, scaling Tough Tech and Climate-tech startups and Somverille's growing innovation economy," according to Rafi's 468-page master plan summary. If approved and developed, the campus would be one of the largest tough tech campuses in Greater Boston, the Boston Business Journal reported.

Although the proposal doesn't include any housing due to zoning — a concern residents had with the proposal, according to Cambridge Day — the developer has pledged $27.9M to the Somerville Affordable Housing Trust Fund and $5.5M to the local jobs trust.

In 2015, Rafi's Yip was on a mission to build a new skyscraper in the city, but since then, plans seem to have fizzled. The company is also working on a 43K SF lab project at 599 Somerville Ave.