As I contractor if I am installing a customers product or supplying my own, I am charging full overhead and profit above the install cost. I try not to allow customers to supply materials and when they do I tack on my overhead and profit in to the labor. Remodeling is one of the most time consuming services and if your not covering your overhead and profit in the materials and labor you will not last long in this business. At the end of the day after all said and done, making a 15% profit is respectable. Think about it, your the designer, the gofer, the physiatrist, the builder, shopper and the banker until you get paid. Never be intimidated to support your price, deliver a quality product and support it with proper pricing. Never let the customer supply there own materials. Movie theaters don't let you bring in your own pop corn, so why should contractors be any different.
As the home owner, I am providing about $8,000 in materials. This includes the cabinetry, fixtures, faucets, countertops, lighting, toilet, glass in-line shower door and tile. Received two quotes. One contractor wants $25,000 to demo the bathroom, convert the existing tub to a tiled walk-in shower, tile the floor, and install my materials. The other wants $27,000. Using the previously mentioned 60/40 labor to material rate, I would be paying more than double for labor...that's insane. Some contractor's need a reality check.
Bathrooms traditionally have few to no natural lighting sources, so any lights that you include are important to the function of the room. Lighting helps not only with the use of the bathroom, but specific task lighting in the vanity and shower areas help enhance your experience there. Lighting for the bathroom can take several forms. The most common include:
As a contractor I can tell you that most reputable contractors probably don't need your job, and if you make things too complicated or troublesome, they will move on to other jobs that don't throw up red flags. Much of what you ask for here is reasonable, but bringing a second contract into the equation can set of some alarms that you may be a difficult customer to work with or even a litigiously minded person who is likely to try and bring a lawsuit whether deserved or not. Anything you want covered should be in the original contract.
It's totally legitimate for a professional to charge you for a design, at least in some situations. If the contractor has a book of ready-made designs and just pulled one out to show you, then you're right that s/he shouldn't charge you. But if someone does a design that conforms to your room's dimensions, with the features that you want, then that person has invested time in creating a work product. Some contractors and architects think that's just the cost of doing business, but many others consider that their time is worth something, and they charge for it. You just need to let contractors know that you're not looking for that kind of custom work, and not willing to pay for it.
I acted as general contractor and did all my own demo to remodel my 6x8 bathroom. I hired subs individually to do most of the work - an electrician, a plumber, a drywall guy and a tile guy. I painted the walls and the ceiling. I replaced everything except the cast iron tub. Materials and fixtures cost around $2000 and labor was about $3000. My subs had no problem with me supplying the materials, because I discussed their job scope in advance. This project took 6 months but I did have another full bath to use in the mean time.