For bigger projects, interior designers often charge $50 to $200 per hour, or $5 to $15 per square foot. Smaller jobs may only cost $10 to $20 an hour. While most designers will take on more work if paid, some may turn down a job if they cannot find enough money with what is available. Others may choose not to work at all certain times of the year or if they are sick. In addition to billing by the hour, interior designers can be paid by the project or based on a percentage of the sale price of the home. If they use up little time designing, they may charge more per hour or have multiple bills over a period of months or years. Some firms include their fees in each monthly rent check while others add them on at the end of the contract. Either way, their fee should be clear before you begin work. Interior design is not a profession that can be done as a side gig or part-time job. It takes at least some full-time commitment for months or even years at a time so it is best left to those who can afford to make some space in their schedule for this work. However, even with these limitations, there are many opportunities available for those who know how to search out these opportunities.