The SBA 504 offers a fixed below-market rate loan to buy, construct or improve commercial real estate or to purchase heavy equipment. Apply for a business loan with Community Bank of the Bay in Oakland, Danville or San Mateo.Step 1: Check your eligibility. Before you even begin your application, make sure your business is eligible. Read through a listing of SBA's headquarters and field offices, including District Offices, disaster offices and loan and guaranty centers. Headquarters Offices. Instead of applying and reapplying to a number of places, you will only need to fill out one application with Opportunity Business Loans. Find out how to apply for a small business disaster loan if your business suffered damage and is in a presidentially declared disaster area. Starting a business from scratch can be challenging. Franchising or buying an existing business can simplify the initial planning process.