There were two big dollar rooms that were not included in the cost of our addition, the kitchen and the bathroom. For our bathroom there were a couple of design aspects that I wanted to incorporate. First I had spent some time in Brasil, and I really admired how the floors of their bathrooms (and all their rooms for that matter) could be cleaned by dumping out a bucket of water and scrubbing away. With that in mind we tiled all the walls and the floor, and had a drain in the center of the room. To make cleaning easier we had a suspended walnut vanity with a concrete countertop that I made, as well as a wall hung toilet. That made it easy to pass a mop anywhere across the floor. The shower was open and had a lip to keep the water in place. For a tub we designed and fabricated our own stainless steel japanese ofuro (soaking tub) for about $500. The most expensive things in the whole room were our toilet at $800 (which besides being wall hung was also dual flush) and our shower faucet which came in around $600. A large wall to wall mirror above the vanity along with the white subway tiles on the wall kept the room feeling much larger than it really was.Lessons learned:1. Once again the DIY spirit can save a lot of money. The biggest expense on the ofuro was materials. After that it was just getting someone to understand your vision and make it come to life.
2. Use simple materials when possible. Our white subway tile was from Home Depot and was way more affordable than a lot of other tile.
Source: Grace Bonney