This is a function of a couple things.  For existing commercial income properties, the loan amount is dependent primarily upon how much money is left over each month once all of the operating expenses are paid.  This is called the Net Operating Income.  We need: 

A description of the property, a lease summary or rent roll, physical description, square footage, lot size, and its condition.  From this information we get get a pretty good idea of the maximum loan the property will support.

For small business real estate (also called "owner-user") we need to know more information to qualify the cash flow.  This includes the business' financial statements so that we can see net income, officer salaries, and depreciation.  We also need to know the borrowers' personal debt situation to qualify them in addition to the property.

For commercial construction projects, you need to be concerned with both the end value of the project and the total costs in addition to all of the information needed for the type of owner, above.  

We start you with (just click on the approprate document to download):

A comprehensive Detailed Broker Underwriting Checklist,
An Owner-User Prequalification Worksheet, 
A Commercial Investment Underwriting Spreadsheet,
And our Loan Submission Documentation.

to help you gather the necessary information to take you to the next step ...

This is where the rubber meets the road and you save the most time and money.  In commercial lending we focus on the property, but don't forget the guarantor.  We assemble documents related to the property's location, structure, value, and use.  Then we assemble information on the ownership entity, the guarantors, and the transaction (such as the purchase contract, escrow, title).  For construction loans, the list includes even more items. 

Finally, the entire package is submitted to underwriting to determine if there is a loan to be funded.  Thus far, you've committed none of your client's funds for third party reports ... 

If the underwriting agrees with your analysis, they issue a Letter of Interest or "LOI."   This is basically your "go ahead" and is equivalent to a residential "pre-approval."  As indicated above, it's also usually done for free. 

Once you receive your LOI, you have your client sign it and send it in with a check that covers the cost of the appraisal, environmental Phase 1 report, and other third party reports that underwriting  indicates is necessary to fully fund your client's loan.  That check is called the "Good Faith Deposit" and it lets the lender know that your client serious about proceeding.  Any amount of the deposit that is not used in the Due Diligence process is refundable or is credited to the client at closing.

Remember:  Third party reports are used to verify the information provided by the client.  If all turns out well, you are on your way to ...

Once the third party reports come back, assuming there were no surprises, we do a final review of the file, known as "loan committee."  Once the loan passes this stage, the loan documents are created.  At this point most borrowers request a copy of the documents for review by counsel to clean up any inconsistencies.  Once those items are taken care of, the loan documents are signed, returned to the lender, and funds are sent to escrow.