Bidding per plan is not bait and switch.
If you are going into Design-Build then you must have the contract documents to support it and a customer who trusts you enough to build efficiently.
You CANNOT take a HARD-BID mentality into D-B. They are two different worlds.
Buy using YOUR engineering talent some (soon to be) poorer EE is being cut out. Those dollars must now flow to you. BTW, you will not likely be as efficient as an EE as you think. Being an EE is a whole different world from being an EC.
The terrible business climate is causing everyone to go a little bit crazy -- on the way to bankrupt.
The design neutrality of an EE's plans allows GC's to place the project out to random bid. The bidders, without any design input, can't be accused of rigging the game.
If you are going down the Design-Build route then you must permit the GC to have a second negotiation with regard to extras and deletions. Typically, a job specific (ie the contract at issue) cost structure must be maintained by the EC. Adders and subtracters are then factored into the baseline bid. The D-B EC is permitted to make a profit, but is not allowed to make a killing.
I must say that I've never seen D-B full rituals used for something as simple as a TI. But the industry is now running most of the commercial action in this format.
Perhaps try cost-plus...
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More generally all of this is symptomatic of too many players and not enough action.
Meaning that winning such contracts may well equal losing one's business.
It's much better to focus entirely AWAY from such hyper-competitive bids and perform service work.
At least you might survive.
All principled low-ballers will go bankrupt.
BTW, such clueless GC's indicate where THEY stand on the totem pole of construction economics -- and that's on the bubble.
