The answer will vary depending on location, current/local economics, existing house value (will it interfere with local flood ordinances), your tastes, age of the home and more- are you adding plumbing? upgrading electric? enclosing existing space? adding a/c or heating?
For a “quick and dirty” calculation, try:
1,000 sf x $150/psf = $150,000 * 12% = $18,000*
This is by no means an accurate reflection of your specific project but a good starting point. Architects sometimes have a base fee, a minimum that they cannot go lower than because a project has certain mobilization costs. They might also need to hire consultants (engineers for structural, electrical, mechanical, plumbing, civil; landscaping; specialty lighting, etc.) Percentage of cost, as illustrated above, can also vary - typically anywhere from 8% to as high as 20%, again depending on the level of quality you expect to see in the project. Architects don’t just design square boxes.
I agree with the basics of Red Shoe’s answer. It’s impossible to estimate a hard fee without project specifics but 12% of construction cost is a good place to start. But there is another question to ask. How do you know you need 1,000 sf of addition? Hiring an architect can help you determine both your needs and establish the feasibility of a project.
For example, we typically start a project with a Feasibility Study for a lump sum fee, this starts at around $5,000. In this study we survey the existing conditions, conduct a zoning & code analysis, establish needed program, and then provide a concept design or in some cases a few schemes to consider. This is how a client can intelligently know whether or not they really do want a 1,000 sf addition.
Then if the client wants to proceed we roll all of that data and design into a comprehensive building design. Quite often clients walk into the study phase thinking they want one thing (1,000 sf addition) and walk out of it wanting another (say a 800 sf addition and 200 sf of renovated interior space) thing all together. In the end this can save the client money and result in a higher quality, un-rushed, product.
In Aggieland, Texas by-the-hour serves the customer best.
These results are usually in the $1.50-$2.00/Total SF (anything with a roof or foundation or remodeled) in design fees, exclusive of any structural engineering fees & color printing of plans.
Note that both the design & construction fees are typically x2 higher than new build costs, so many first are assigned the accounting homework of selling, then applying profits to a new build elsewhere … to compare to the resulting remodel/addition fees, not to mention resale values of both if needing to liquidate/move in future.
