I've just been through this--but with digging up the slab of an existing house (in three directions, not just for the steam oven)! This is a change order, right? The services (plumbing and electric) are already built and in place? If so, the amount might not be excessive. Not all ovens are the same--they might have to pull additional electricity to the oven area, and that's assuming you haven't topped out your service (probably haven't). It also means installing what is essentially a sink in a new area, including having the fall of the drain, the drain vent, and water supply. Besides the plumber and electrician, there's whatever the GC has to rework, move, reschedule, etc. And they usually charge a premium for change orders as a way of dissuading you from messing up the project too often.

For you to be satisfied and understand the project you're proposing, you could ask builder to walk you through what it will entail to put the steam oven in. Then you'll be better armed to decide if it's worth the money to you, or to negotiate the price.

Thanks for your reply, plllog! Let me clarify, we signed the contract on this house recently. It's a new construction, 90% completed. The kitchen cabinets are in but no backsplash and no appliances yet. We negotiated for him to give us the $$ for what he was going to spend on the appliances, and allow us to choose our own. It's in the contract that he has to "install all appliances... to be selected by Purchasers, and adjust cabinetry and countertops to fit, if necessary." I take that to mean that he has to install 10 steam-ovens if I wish, at HIS cost, no? To be fair, if he had just asked me to pay for the additional plumbing required for the steam oven, I would have done it, but the amount he's asking seems exorbitant to me.

Okay, I get it. This actually makes it harder to pick apart, but I'm sure you can do it and come up with something fair. :) Looking at the intent (the exact wording is for lawyers and all, and I'm sure you don't want to go there). Are the builder's appliances high end like yours (Viking, Monogram, Architect, etc.)? If so you probably have a point. In general, I'd say that pick your own appliances and adjust the cabinetry as necessary would mean to the builder choose your DW and he'll adjust the opening, and do what needs to be done to the counter to fit. Choose your double oven and he'll trim out the cabinet to work with it. Etc. Not 10 steam ovens. More like if you had a nice kitchen with a couple broken appliances and needed to get something that would fit the locations, power, etc., he'd put them in place and make whatever repairs were necessary to make it work.

I'm not advocating playing dumb, but unless you have a lot of experience in building and remodelling, you can, without being a stereotype, go to him and say frankly that you don't know why it costs so much to install your steam oven. Ask him to explain the costs to you in a non-adversarial way. Don't talk about what you know, but listen to what he tells you.

Again, in a friendly way, if he says that he'd need to pull more electricity there for your fancy German babies, (wide eyed innocence is very non-confrontational and non-threatening), ask why that isn't covered in the installation. I frankly don't interpret "install" as including new services, but get him to say so. Ask him how much putting in the plumbing could cost, because your friend had a sink put in for...(get a number from a friend). Etc. You may find that by the time he's done explaining you'll find a place to negotiate to that both of you are comfortable with.

You can also say, well, in that case you'll get the steam oven with the tank, so it won't be an extra charge. If he agrees to that, and you have it in writing, you can call back a couple hours later and say it was bugging you, and you really want the plumbing, and you'll pay the plumber to come in and do the fittings.

But get an estimate from a plumber or two, as well, because it might just cost a similar amount as the builder quoted.

Oh! Besides the water in and the drain, etc., out, you'll need a water shutoff, and it has to be at a certain (usually inconveniently placed in your cabinets) height, and easily accessible.

Thanks, plllog! We're planning to meet with the builder again this week, and will try my "wide eyed innocence" on him!