Santa Rosa in Sonoma County and Vacaville in Solano County are roughly an hour’s drive apart, but they’re worlds away in the pace of housing construction.

Santa Rosa, the county’s seat and its largest city, with an estimated 177,000 people, had issued building permits for 47 homes, all single-family, in the first half of this year, totaling nearly $12 million in construction value, according to CIRB, part of the California Homebuilding Foundation. Renovations fill out the rest of the $26.2 million in residential permit value for the period.

Issuance of building permits is one of the last governmental steps before home construction starts, coming after months to years of seeking green lights from local, state and federal agencies, depending on how much was already done to get such signoffs recently before the developer moves toward construction in earnest. That’s why building permits are a economic bellwether for construction industry activity.

Of about 2,200 homes in projects various stages of review, Santa Rosa had building-permit applications for 845 housing units at mid-year, with about half back in the developers hands to work out financing, environmental-impact mitigation and other issues, according to a city report. Of the other half, the city expected another 100 units to get under construction this year. Already, 70 homes were completed, and 80 more given the green light but are awaiting financing, labor, the right timing, the city said.

By comparison, Vacaville, Solano’s third-largest city at 98,000, edged out second-largest Fairfield for the most residential construction permit value in the county in the first half. Vacaville issued permits for 206 homes, including 167 single-family dwellings, with $49 million in value, while Fairfield issued 179, all single-family, totaling $47 million.

Out of 921 units ready to pull permits in Vacaville this year, about 400 are expected to be built, which is the pace of building in the city in recent years, according to Barton Brierley, director of the Community Development Department.

Santa Rosa had 251 homes under construction in June.

Among them is the 54-home Aria Place development off San Miguel Avenue in northwest Santa Rosa, Morgan Properties has 25 single-family homes in phases 4 and 5 of the project under construction or about to get underway, according to proprietor Dan Morgan, who has built more than 300 homes in Sonoma County since the first project there in 1993.

The first three phases of Aria Place sold out before completion, and the next homes are expected to be ready to delivered to market between October and March 2018. Five of the 12 homes in phase 4 of Aria Place, which are being framed now, are in contract for sale. They’re priced at $549,000-$649,000 for the 1,250- to 1,914-square-foot homes. Construction on phase 5 is about to start.

“The rains caused us to have a gap in production, so we don’t have anything to deliver right now,” Morgan said.

The project has been built in phases of nine to 13 homes each. That has been based as much on the flow of project financing as on demand, he said.

“We’ve got really good momentum now, and the bank is seeing that, and they’re happy about the performance, so they’ve cut loose a little more money,” Morgan said. “That, and demand has been so strong, why not build the phases to the market?”

In Vacaville, most of the developments are large, Brierley said. For example, the Brighton Landing project on the east side of the city was approved five years ago for 780 units, and 50 to 75 homes are built at a time over one to two years.

Morgan Properties’ other permitted Santa Rosa project is about to start framing. The 17-home Mark West Village across from Sutter Regional Medical Center on Mark West Springs Road is set for early 2018 completion, is going up all at once because of expected demand from medical workers and the project’s proximity to Highway 101.

A skilled worked shortage has been a factor in how quickly work can be completed, Morgan said.

The North Bay housing market stalled in mid-2006 then went into reverse in 2009 as the Great Recession put a sizable percentage of homes back in lenders’ hands, short-sold or having their mortgage balances reduced.

Jobs that some framing companies had been able to accomplish in three to four months before recession are now taking up to six to nine months, even with good weather because of the shortage of workers, according to Randy Waller, broker and owner of Santa Rosa-based W Real Estate. His father, Ed Waller, co-founded Shook & Waller Construction, a major Sonoma County framing contractor.

Smaller sizes of project phases may be a key problem in getting many North Bay locales out from under the housing shortage, Waller said. His firm is marketing Aria Place and Mark West Village as well as four other developments with a total of 263 units, including one of Santa Rosa’s largest projects, HybridCore Homes’ 150-unit Paseo Vista off Dutton Avenue.

“One of reasons our market is so tight with inventory is we don’t have ability when market heats up to spring up hundreds of units to keep appreciation from running,” Waller said. “In Sonoma County, we don’t have many sprawling 100- to 300-unit subdivisions. They’re mostly infill units. Anytime we roll out a 10-unit phase to sell, we have people buy them before they are finished. So we’re not seeing new construction having an impact on the supply.”

But there are some sizable projects in the offing. There are the planned 800-home development on the former Sutter Health hospital site on Chanate Road in Santa Rosa, a project that just this summer was sold to a group led by Bill Gallaher of Oakmont Senior Living to start the entitlement process, and CityVentures’ 175-home Fox Hollow project on Dutton Avenue.

Accessory dwellings, often called“granny units” or duets, have been discussed as a way to create more housing rapidly. Morgan Properties has submitted plans to Santa Rosa and held a neighborhood meeting for a 45-home development at the northwest corner of Marlow and Guerneville roads. Called Marlow Commons, it would have second units with 28 of those homes.

“I’ve built granny units 40 or 50 times in Santa Rosa, but they suffered in value during the downturn with investors because of the requirement that the owner live in the home,” Morgan said.

A key difference between his current project with duets and previous ones is zoning, he said. The Marlow site is zoned medium-density residential, which allows for attached units, while other areas of the city where he’s built them before were zoned low-density residential. Granny units with the latter zoning were considered benefits to the property owner and came with the owner-occupied condition.

And about 10 miles south of Santa Rosa, Rohnert Park has nearly 6,800 homes in the pipeline, with 80 completed this year and 112 under construction, mainly in the 1,853-home University District project on the east side, and 560 expected to get built in the next 12 to 18 months, according to a city report. Another large project where construction hasn’t started is Codding’s 2,100-home residential component to SOMO Village.

“There is product out there, but it is not enough to keep pace with demand,” Waller said.

For Vacaville, because it sits on Interstate 80 between Sacramento and the Bay Area, attracts homebuyers who commute to the state capital as well as San Francisco and the East Bay, Brierley said. The city also has major employers, such as the biotechnology company Genentech, which has a 100-acre campus in Vacaville and has been expanding it recently.

Rather than having a number of infill projects in the pipeline, as in Santa Rosa, Vacaville has land for projected population growth over the next 20 years, Brierley said. That would accommodate 2,860 homes set for three of the city’s largest planned developments: Lower Lagoon Valley, with just over 1,000 units; North Village, with about 1,200; and Robert Ranch, with 760.

Santa Rosa, Vacaville and many local building and planning departments had to dramatically cut staff during the housing bust and Great Recession. Vacaville lost about one-third of its staff. Though it has been slowly adding positions back, other measures were needed to keep up with demand for permits, Brierley said.

“With a combination of improving efficiency and adding contract staff, we’re still about to turn around projects in the target timeframe,” he said.

That’s four weeks between application for building permits and the first plan review then two weeks after resubmittal for the second plan review.

“For building-permit application to issuance, it usually takes two plan reviews, so about seven weeks, and we’re meeting that,” Brierley said.