I'm not sure why you would have bid your project in so many ways. Was this your choice of the bidding contractor's?

General contractors (like everyone else) each have their own individual preferred method of contracting for construction, based on how they like to work and invoice. That said, an experienced builder will have probably used every contract type there is during their building lifetime, so your preference for cost plus fixed fee should not be a surprise.

Owner supplied items are often a PITA for builders, but it's a frequent and common approach by many owners, particularly those in the design professions. Every experienced builder should have experience with such situations, both good and bad experiences!

That said, owner-supplied items are really a small issue in comparison to the overall project and easily incorporated into the contractor's fee for such things.

Good luck with your project.

Thank you, Virgil. The first three bids just happened to have come in that way. It makes it a bit challenging to compare them so that's why I'd like to request a fixed flat fee format from the fourth builder if it turns out that's the way to go. I appreciate all comments.

You have created a dilemma by not including the contract in the bid package.

It is impossible to compare a "Cost of the Work with a Fixed Fee" contract (the term "fixed fee" includes a "lump sum fee" as well as one based on a "fixed % of cost") vs a Lump Sum contract.

For the Cost Plus contract the contractor would only submit a "Budget" with no limit on the final cost of the project which is entirely different from a Lump Sum contract where the price will not change unless the scope of work changes.

To make these contract types more comparable you would need to ask the former to include a "Guaranteed Maximum Price". That is closer but still not the same as a Lump Sum contract. The GMP would allow you to keep the savings if the cost did not reach the GMP so it is better for you but not for the contractor and the bids will reflect that.

The only way to resolve this dilemma is to specify the contract type and ask the bidders to resubmit their proposals.

The only time I have seen a GC agree to a Lump Sum Fee on a Cost Plus contract was when they would supply much of the labor rather than using subs thereby allowing the GC to mark-up the cost of that labor and bill it as a Cost of the Work like a sub would. For a Cost Plus contract, one must pay close attention to how sub-contracts will be bid and how much of the work will be done by the GC's own forces.

Bidding a Cost Plus contract is so difficult I will only use one if the GC is selected on the basis of an interview and his mark-up rate and agrees to allow the owner to approve the sub-contractor lists and select the winning bidder (with the GMP modified for any increase in cost above the lowest price).

Thank you Renovator8. To clarify, are the terms "fixed contract price" and "lump sum contract" synonymous?

More important than the form of the contract is the trust factor. There are so many ways a sharp contractor can boost his cut--as Renovator8 points out--that character, reputation and experience should be a paramount factor in making your choice.

Thank you, Worthy. How right you are. The trust factor is paramount.