The fee itself does sound pretty reasonable for the work (if I understand the work correctly).

However, I don't know what the reference to basing a fee on true market value of the project means.

Perhaps if you gave some more information it would be helpful. The cost of the work to get the addition permitted is $25,000 and is for what? What is the contractor doing? What is the scope of work for each the Contractor, the Architect and the Structural engineer. The drawings are to re-create the addition and receive building department approval of it? Have you spoken to your building department and gotten their approval of this approach or were they the ones who suggested it?

I would assume that the architect would therefore do a sort of as-built set of drawings and the structural engineer would do the same, and the structural engineer in particular would have to research the home to determine just what was done so he could then reverse-design his drawings.

Again, it's an unusual situation so it's hard to weigh in on whether it's correct or not.

We need to reverse-design our home in order to do come up with as-built drawings from which to complete our remodel design. The quotes I have received for the reverse drawing (not including the structural engineering portion) have been approximately $2,500-$3,000. Our home is a California side split level on a hill; it is a 4-bedroom, 3 bath home, just under 2500 square feet + 3 car garage. We're in Southern California.

I'm not sure I understand why the structural engineering costs should be so much higher than the architectural drawings. The estimates I have received always put the structural engineering costs at less than half of the cost of the architectural design/drawings since the structural engineer works from the architectural/as-built drawings and adds his/her own layers to those drawings. I would question that portion and the "miscellaneous" portion of the cost break down. Nearly $1000 seems high for a pad.

Well, I think that the structural engineering costs in this case have to do with the fact that the structural engineer is going to have to do more work to figure out whether the addition was actually done to code. Whereas usually a structural engineer would work from the architects' layouts and create a structural design from which to build, this requires them to go under the house, go in the attic, check whether there are hold-downs and what size they are, if they're bolted properly, etc. If I were a structural engineer and had to put my stamp on a set of structural drawings for something that's already built, I'd definitely charge more.

I spent $5,000 on a structural engineer -- 2 story addition -- if that helps.

I'm assuming that the Architect is there to get proper plans submitted to Code Enforcement.

Then the Structural Engineer is there to opine on the footing, foundation and framing that is now up. On site work is going to cost more than working off an architect drawing.

And the GC is going to coordinate those subs, the inspections and corrections. For a Fixed Contract Price, $25,000 is very reasonable... you don't know what's going to need fixing. If that's just a Cost Plus estimate, then you're on the hook for what ever it takes anyway.

I spent $2,000 to have an engineer draw the framing plans in his comfy office... $3,500 for an onsite engineer evaluation (plus $974 for concrete core samples, or soil tests and such) sounds pretty fair. Make sure the contract states the responsibilities of each of these subs.

I did a big two story addition also. I paid a total of about $6000 for architects. $2800 for the first idiot. About $3000 for the second guy to fix the first guy's 'work'. This includes about $900 in engineering calculations and stuff. For for being so technical....