I'd be more interested in getting a bid from someone your architect knows, and works well with. In your situation, I would talk to a few, and ask questions like, what is important to look for in hiring a structural engineer? Without further information besides knowing your "designer" likes one, I would definitely talk to/get bids from 2-3 of them.

I'd also see if my GC works with any. But if not? I know nothing about structural engineering. All I could ask about in a meaningful way is price.

So I'd go with one that was recommended and not bother shopping it around.

(When I did an addition, I let my architect use "her" guy. Nothing has yet collapsed...)

Structural engineering work is typically billed by the hour. Rates should reflect market prices in your area. You can certainly inquire about the engineer's hourly rate and you can ask for an estimate of the time required, but it would be non-binding. You could also ask for a not-to-exceed price based on a "worst-case" estimate of the time involved.

As is the case with any service provider, the lowest hourly rate doesn't guarantee the lowest total cost. The engineer who charges more, but is more efficient due to their experience level, better software, etc. might get the job done in less time and at less total cost than the guy/gal with the lowest hourly rate.

I am a very skeptical person and have trust issues so take this with a grain of salt!

we had a contractor come by who insisted that a wall was load bearinto. he also insisted on having his architect take a look because he was sure it would be load bearing. He also emphasized the increase in cost of removing the wall if it was load bearing.

we got vibes like this guy was gonna tell us the wall was load bearing whether it was or not, so we hired a structural engineer, who confirmed our suspicion that the wall was not load bearing. We told the contractor and he still was not willing to accept it (we didn’t hire him).

In the future, I will always hire my own structural engineer. I don’t think all contractors are trying to drive costs up this way, but I think some do, and it gives me piece of mind to have a statement from someone who is not associated with someone else who is Trying to make a profit on my project (not saying making a profit is wrong, btw).

Licensed professional engineers commit to practice according to a professional code of ethics (full disclosure: I'm a licensed P.E.) A licensed professional engineer isn't going to risk his/her license and livelihood schilling for a contractor. It doesn't matter who writes the check, you'll get the engineer's professional opinion.

Thanks, everyone. I really appreciate the feedback, especially as someone who is newer to the process.

Unless you are building an addition with lots of beams and cantilevers and posts and crazy structure everywhere, the time involved in structural design is not nearly as time consuming as the architectural design and construction drawings are. In other words, PE’s are generally happy to do the work if you ask them but to get multiple PE’s to bid on designing a couple beams and footings will not be worth their time and you will strike out. Be happy the designer knows someone.