There are CAD drafting systems for computers, there are also those, other than Arch. who will convert your drawing for you.

There are distinct similarities in using Arch. and design/build.
One of which is that if there is an unforeseen situation, behind the wall coverings, within a ceiling cavity, they both charge for the corrective action required, both must meet your's as well as the building authorities approval.

This is my course of action. If you are satisfied with the design, convert it to paper, submit the plans to a civil eng. for approval of structural design, submit it to the city for plan check, shop for contractors.

Thanks.

How does one go about finding a civil engineer?

Also, if we know that we will have to move some utilities (ie: plumbing) as a result of moving the stairs, will the engineer be able to plan for that? Or does that require an architect?

Non of this "requires" an arch. that would be your choice.

When you said, "My husband has actually completely designed the space." I made an erroneous assumption, made obvious by "we will have to move some utilities (ie: plumbing) as a result of moving the stairs, will the engineer be able to plan for that? Or does that require an architect?"

However, it does sound like you are headed in the right direction.

There are required parts to a formal Plan document prior to submittal for plan check review.

1st The plot Plan, which is a birds-eye view of the legal
property, showing all structures.(1"=20')
2nd The Floor Plan/s are all of the walls as they exist
with all doors, windows, and openings shown and all
of the rooms labeled for their legal use. Since you
are working on both floors, use separate sheets to
indicate the existing configuration as well as the
proposed changes for each floor. (1/4"=1')
On a separate sheet you can detail specifics both in
plan view and elevation. (1/2"=1').
3rd Framing sections and details will take some
expertise, mostly in the determination of how the
existing structure is built, and how the proposed
changes will affect it and any remedial action
which will need to be taken.
Those details will be contained in a series of
documents provided by the civil eng.
When these details are incorporated into the Plans,
2 copy's are returned to the eng. as a completed and
assembled formal Plan Document, to which he will
affix a wet stamp and two copies of his
calculations, also stamped.
4th Building elevations are what you want the finished
product to appear "from the street".

Additionally there should be a sheet containing a complete list of specifications, IE. if you want a wall paper whose pattern is a three legged green and purple nuthatch, this is where it goes. This is where you remove, as much as possible, "assumption".

All of this can be accomplished by someone with a CAD system (computer assisted drafting.
You can purchase this system. There is a learning curve.

Here is a link to a resource for ENG. in your area;
http://www.thebluebook.com/

FYI, Eng. is an exact science, based upon assumptions.

Knowing the language always helps;
http://www.netfunny.com/rhf/jokes/91q2/contract.html
http://www.schererbros.com/homeowners/terminology/A.php
http://www.ownerbuildersolutions.com/glossary_index.htm

Enjoy

I talked to several architects who wanted 10-15% before I found two who worked for a flat fee (for comparison purposes, it was the equivalent of about 4%). I too had drawn plans and mostly speced them except for the structural stuff. I realized that I didn't need a design architect, I needed someone who knew the code and knew their way around the building department and they were the ones who worked on a flat fee based on what it was going to take to get building department approval.

I would not go the design/build route. You're still paying for the plans but you can't shop them around. You don't know what the cost of the build is going to be until you've invested a lot in the plans but then you can't take the plans to other contractors. Also, to my mind, there is no incentive for them to design economically since they are making money from the implementation.

I've used the same, great architect twice. He did not tie his fees to the costs of the remodel. He simply charged for the hours he put in. He told me that if he was fully engaged in the whole process from start to finish, it would probably be about 12-15% of building costs. the first time I had him do everything from start to finish, and it did work out to about 14%. The second time, I was more savvy and did not need him to be so involved, and it worked out to about 6%. Get an honest architect who will charge for his services by the hour like other professionals. There is no reason you should pay more just because you have granite counters rather than formica.