@advanture.buddy: Bathroom & Toilet
After debating on whether or not to have a bathroom and a shower, we opted for a bathroom only (we heard from other vanlifers that it tends to become a storage closet instead, we plan on spending winter in the van and plumbing would have been a pain, etc). It worked to have a bathroom anyway because our bench seat has a high back; as a result, it made sense to have the space behind the seat closed off. Plus this way it also provides separate living areas, and while we wanted to keep an open feel in our van, we actually like our sleeping nook behind the bathroom and kitchen!
The framing was pretty simple: We decided to keep the wall between the front bench and the bathroom thin (to save on space) and the wall between the bed and the bathroom is framed with 1x3's, which enabled us to put some cutouts in (see photo below).
The walls were made out of brown board covered in wall paper (made using cardboard templates and a pliable piece of aluminum to fit the walls to the curve of the van). We installed a retractable shower door, which is pretty cool, but the verdict is still out on whether or not it is necessary.
After deciding not to purchase a composting toilet (we found them too expensive to justify buying one), we opted to make a simple system ourselves. After doing some research, we found that it was essential to 1) limit your van bathroom usage if you DO use it, and 2) to really try to separate the "liquids" from the "solids" (we have only used it for "number one" so far, and we can say that it's quite nice to have in urban settings and at night!).
We ended up buying a plastic toilet from Home Depot. To separate the liquids and solids, we created a system that uses three elements: a bucket (that sits in the toilet itself), a funnel (cut to fit in the front end of the bucket, which then drains into the large plastic container below), and a plastic bag (hung over the back end of the bucket). This way the liquids are "funneled" into the toilet, while the "solids" can be kept separate in the bag.
We do plan on using the bathroom as a closet to dry our clothes during the ski season -- we will most likely fashion something above or below the toilet to catch the melting snow from our jackets and pants.