Fixed fee, sometimes called lump sum, is probably the most common fee structure I see architects using today, and it's easy to understand why it's appealing. You know from the outset roughly what your project will cost and roughly what your architect will cost. For a client trying to plan a budget and keep control over spending, that predictability is genuinely valuable.
But a fixed fee doesn't automatically mean you're getting everything. That's the part that trips people up, and it's the single most important thing to understand if you're comparing fixed fee proposals from more than one architect.
The Same Number Can Mean Very Different Things
A low fixed fee sounds appealing on its face, but a fixed fee is only ever a number attached to a defined scope of services. Two architects can both quote a "fixed fee" for your project, and if their scopes are different, you're not actually comparing the same thing.
The two phases that most often get quietly reduced or dropped entirely from a fixed fee are construction documents and construction administration. I've seen permit sets that run ten pages with only four actual lines of information on them, technically a set of drawings, but nowhere near enough detail for a contractor in the field to know what to build without constant guesswork. When an architect's fixed fee only carries a project through permit drawings like that, you're paying for maybe half the actual work a project needs, even though the number on paper looked reasonable.
Construction administration gets cut for a similar reason. It's the phase where the architect stays involved during construction itself, visiting the site, answering the contractor's questions, and making sure what's being built actually matches the design intent. It's easy for that phase to get left out of a "cheaper" fixed fee, and it's also one of the first things clients get tempted to cut later if a project starts running over budget, which is a mistake I'd caution strongly against.
What I Include at Tight House
When I do offer a fixed fee, I build it to include construction administration, full construction documents, and interior selections, not just a stripped-down permit set. I think that's the right way to do it, because a project that only gets you to permit and then hands you off leaves too much unresolved for the contractor and, ultimately, for you as the client. If I'm quoting a fixed number, that number reflects the full scope of getting your project built the way it was designed, not just getting it approved on paper.
This is also why comparing fixed fee proposals purely by the bottom line rarely tells you much. If one architect's fee is notably lower than another's for what looks like the same project, the difference almost always comes down to what's actually included, not some architect being cheap for the sake of being cheap or expensive for the sake of being expensive.
Know the Limits Before You Sign
A fixed fee contract also has to spell out limits, because unlike an hourly arrangement, the architect needs to define upfront how many design options you'll see, how many rounds of revisions are included, and what happens once you go beyond that. That's not a bad thing, but it does mean you should understand those limits before signing. If you know you tend to want to see a lot of options or go back and forth extensively before settling on a direction, it's worth having that conversation early, because anything beyond what's defined in the contract becomes an additional service, billed separately.
None of this is meant to make additional services sound like a trap. It's simply the tradeoff that comes with a model built around predictability. In exchange for knowing your number upfront, both you and your architect agree to a defined scope, and staying mature about what falls inside versus outside that scope makes for a much smoother working relationship than being surprised by it later.
In the next post, I'll walk through hourly and hybrid fee structures, where the tradeoffs run in the opposite direction, and why a hybrid approach often makes the most sense for the least predictable parts of a project.