For those of you who rarely venture south of Interstate 8, it is time to make the trip. Believe it or not, almost one-third of everything being built in San Diego County is in Chula Vista and Otay Mesa. And it is only now beginning.

The explosion of South County is a function of land availability.

South County has virtually all the affordable industrial land in the county (more than 6,000 acres) and most of the developable residential land. The master-planned communities in Chula Vista have more than 40,000 units under development or in the planning stages. Projects such as Lomas Verde, EastLake, Otay Ranch, Rolling Hills, Sunbow and San Miguel Ranch are providing the region’s most reasonably priced housing.

As you may have read, this county has a housing crisis. We know more than 100,000 people who work in San Diego drive home to Riverside County or Tijuana. The key, of course, is cost. Based on MarketPoint Realty Advisor’s latest Residential Trends survey, the average price of a home in Temecula in Riverside County is $255,000; in North San Diego County it is almost $600,000; and in South County it is $367,000. Thus, a difference of $233,000 in price between north and south San Diego County prevails. Since 1996, the spread has become remarkably wide.

More than one-third of all for-sale homes in the county are being built in the Chula Vista/Otay Mesa area. In the first half of this year, in excess of 1,500 homes and condominiums were sold in that area.

All of this has occurred before the state Route 125 toll road has broken ground. SR-125, which will connect the second border crossing to I-8, should be complete by 2006.

Practically all of the county’s leading home builders are taking an active role in South County, led by McMillin, Pardee, Brookfield and Shea. Providing an able assist are Colrich, Barratt, KB, Davidson and many more. All recognize they can produce high-quality housing in South County at prices within the affordability horizon of a substantial part of the San Diego home-buying community.

Of equal importance, several prominent home builders are initiating new attached condominiums often at prices below $200,000. And several new apartment projects have been built, with more in the pipeline, with rents substantially lower than similar projects north of I-8.

Oh, yes, a few other things will abet the expansion of South County:

• A new Calpine power plant breaks ground this coming spring. The plant can serve 400,000 housing units and will jump-start the utility lines needed to expand Otay Mesa.
  
  
• The now-truncated train line heading east will reopen for business. For the first time in 20 years, the manufacture and assembly plants across the border and Otay Mesa employers will be able to send goods from San Diego to the rest of the United States without having to go through Los Angeles. That will dramatically affect the timing and pricing of moving merchandise.
  
  
• The east-west Interstate 905 has now been funded and by 2008 will link both Interstate 5 and Interstate 805 to the SR-125 toll road.
  
  
• The city of San Diego and the county are working on documentation to create infrastructure bonds for Otay Mesa, thanks to a recent state act that allows tax-increment financing there.
  
  
• By 2006 or 2007, a new regional shopping center and maybe a big-box retail center might be developed along the SR-125 in eastern Chula Vista. With more than 3,000 new residences being added to the area each year, demand warrants a new center or two.
  
  
• Almost 1 million square feet of industrial and office space are being built each year in South County, and that should accelerate as the infrastructure is put in place. That volume of commercial development will generate more than 3,000 jobs each year.
  
  
• The South County schools are proving to be as good as some of the better schools in North County. Two new high schools are under construction and Southwestern College is opening a 38,000-square-foot complex to expand its ability to educate the local workforce.
  
  
• The county recently has approved the East Otay Mesa plan. This plan allocates 2,000 acres for employment-generating use, including almost 1,000 acres for a regional technology park. And the city of San Diego is creating a general plan to accommodate the demand for housing in its jurisdiction of Otay Mesa.

If you get a chance, take a South County tour. Travel down I-5 to the border and spend some time at what is hands-down the best outlet mall in our county; the 400,000-square-foot Las Americas. Then drive around eastern Chula Vista. The acreage under development is breathtaking, and the number of model homes is beyond reasonable belief.

It is not a Lewis and Clark expedition. Paved roads are plentiful and most Thomas Bros. map books now include South County. Although the evening weather forecasting maps continue to black out Tijuana as if the city had no weather, they do acknowledge that there is a South County. You should, too.

Alan N. Nevin is director of economic research with MarketPoint Realty Advisors (www.marketpointra.com), a consultancy providing real estate and demographic statistics, feasibility studies and litigation support to the California land use industry and legal professions.