There a number of ways interior designers charge for their services.
Cover all your bases and charge by:
- straight design fees for each ‘area’ of the project
- a markup on items purchased wholesale or with a designer’s discount from vendors like antique dealers
- bill by the hour for things like drafting, installations, shopping, admin work on the project, etc.
A design fee is for conceptual work and can be for an entire project. However, it’s more flexible to charge a separate design fee for each area of the project, as that gives more flexibility when projects change. For example, charge a design fee for a living room, another for the dining room, another for the kitchen, etc.
Markups are sometimes called ‘margins’ and they are the profit on an item a designer purchases for their client. For example, a designer may purchase a sofa for $4,000 wholesale and charge the client $6000: this would be a 50% markup with a $2000 profit on the item. Markups can vary from supplier to supplier or even what type of item it is.
Time tracking is key to good business practices in interior design. Always track both non-billable and billable time so you can see where your resources are allocated. Time charges can be totaled up for any period but a good rule of thumb is to bill your client for all time charges for the month, at the end of the month.
Lastly, always make sure to get each type of charge and rate in the signed contract before starting the project. Having it all in writing is invaluable as the project goes on.