Strong economy and job growth are expected to increase the demand for San Diego office space in 2018 and 2019.

San Diego was ranked No. 15 out of 50 markets in the annual report based on demand and economic potential. The report predicted the region would add around 4,000 new office workers this year.

The big picture: Strong economy and job growth have increased the demand for San Diego office space. Tax changes approved in Congress in December could also mean accelerated economic growth, causing more office workers to be hired.

How San Diego compares: San Diego has some of the most expensive office space in the nation, from an average $275 to $325 per square foot. In places like Milwaukee and Cleveland office space is an average $75 to $124 per square foot. Still, there are markets more expensive than San Diego: Los Angeles, New York City, San Francisco, San Jose and Seattle (an average $325 to $550 per square foot).

Why San Diego may be a hot spot: San Diego fell two places from No. 13 last year. While the ranking moved slightly down, analysts say the region is still a prime spot for office space because of its diverse employment base. The report predicted the office vacancy rate this year would stay around a relatively healthy 13 percent, and office rent prices would increase 2 percent. It said growth will largely occur in biotech, government contractor and professional services.

Also, it said downtown could prove promising to investors because of well-educated millennials who would like to live and work there.

What it takes to be a top market: The Seattle-Tacoma market was ranked as the top market in the report because it has one of the tightest vacancy rates in the nation and Amazon’s major expansion in the region. The tech giant occupies roughly 8.1 million square feet of office space in Seattle, helping push the office vacancy rate to 9.6 percent at the end of last year. Competition for space from other tech companies is expected to increase rent prices 4 percent this year.

The lowest ranked market, Northern New Jersey, is expected to have a 17 percent vacancy rate this year and a 1 percent rent increase.

More amenities: As the economy stays strong, the report said, it may become increasingly difficult to find good workers. This could force companies to utilize their office space to expand amenities they offer employees or promote the office location if it is near a desirable area.

Where businesses could go: Movement away from downtown is a possibility in many markets. “A considerable number of companies will relocate offices to the suburbs to more effectively tap the workforce that resides there,” they wrote, “and to expand space allocations at a more affordable price.” Additionally, the report said national and regional banks are looking more favorably at suburban deals, especially in densely populated suburbs.