Plan
Obviously, it's a good idea to think through the main steps of building the camper, in order to save time and aggravation. I started with a basic list and then kept a running "to do" list for the details within each major step. I kept everything (drawings, plan, todo list, parts spreadsheet, research, etc.) in Google Drive. Like the layout drawing, I went through many iterations of the list as I was trying to figure out how to best get everything done. In some cases, I did things "out of order" because I wasn't sure if what I was doing would work or in some cases it just depended on what I had time and interest for. Consequently, aside from a few critical things like insulation and windows, there is some flexibility in the order of what you do. In addition, looking for parts is an ongoing activity.
Unfortunately, I did not create detailed notes or photos (other than those in Photo section) along with these tasks. If you have any questions, please use the comments feature of the Blog.
Exterior
install water tank
I used a chassis mounted water tank from a popup camper.
install board on tongue to mount propane tank and battery
install propane tank holder and battery holder
install solar panel on roof
Interior
remove all load attachment parts from interior
if necessary, repair holes
remove interior plywood siding
initial setup/sizing of power center, wiring and outlet boxes
12 volt
outlet
lights/switches
pump/switch
furnace
vent fan (I ran wire but did not add a fan)
solar panel
battery isolation switch
110 volt
fridge
air conditioner (ran wire but did not install an AC)
outside outlet
cut window openings/build window frames
install insulation
replace plywood/cut window openings
hookup switches/outlets
install windows
At least one window should be an egress window, I made both egress windows.
install ceiling (¼” laminate panels)
hookup lights
build closet/cabinet by door
run conduit for wiring (both sides)
mount power center
fit propane fridge
I found a cheap used fridge, so I couldn't resist this and it is nice. However, the location I used is not great as the vents are exposed to water/mud splash from the tow vehicle. I came up with a solution to cover the vents, but in hindsight, I think just using the space for a Yeti cooler would be a better solution.
build bathroom walls/install shower pan/build frame for black tank and install tank
hang water heater
For simplicity, especially if mainly camping in the summer, you could probably go with a portable solar water heater.
mount toilet
Originally, I thought I would go with a portable, but decided an RV toilet might help with smell. In hindsight, I think a portable would be a better solution.
build sink/stove cabinet/counter
install propane tank and copper gas lines
tank to T underneath, one side to fridge, other to furnace/stove/water heater
eventually another T below floor to external access by door (future for outside stove/grill)
through floor to T, one side to furnace, other to another T, one side to stove, other to water heater
connectors to furnace, fridge, stove, hot water, external (mounted tbd)
install furnace
install water pump and connect water tank to pump
install plumbing to sink, hot water, shower, toilet
pump to sink with T to hot water inlet and T to toilet
hot water to sink with T to shower head
finish shower
install frp on shower walls
shower rod/curtain
build bunk beds
My original thought was to build a loft bed, that can be raised and lowered, with open space underneath for cots. Although this setup worked and was able to sleep 4, I didn't love it. The loft itself was cumbersome and the cots were unwieldy. Attempting to alleviate, I added a built-in couch/bed unit below the loft (see photos), attempting to make it more functional than cots. The couch/bed unit was also cumbersome, so I tried a futon in place of the couch/bed unit. That was also cumbersome. Eventually, I decided to remove the loft bed and build bunks instead. This took up cargo space (although they can easily be removed and use cots instead), but I think bunks provide the best option for sleeping 1 to 4 people, and they also provide a place to store things while not sleeping. For 1 or 2 people, the bunks alone can be used. For 2 or 3 people, the top layer of foam from the bunks can be placed on a platform, that can be lowered from the opposite wall, making a queen size bed for 2, with another person in the top bunk. For 4 people, place the top layers of foam, from the bunks, directly on the floor (feet underneath the lower bunk) for 2 people and 2 on the bunks. No matter how you do it, it is a little tight for 4 people, even if 2 are children, but it is feasible. After using the bunks for a while, I again decided I just didn't love the setup and succumbed to realistically sleeping 2 comfortably. So, I built a murphy style bed that sleeps 2 and can be propped against the wall when not needed.
wall covering (putty/sand/paint or carpet)
install vinyl flooring
paint ramp with gray deck paint
add chain supports to ramp for patio support
paint roof
Miscellaneous/Optional
install vent fan
install vent cover
install air conditioner
install tv antenna
make/install awning
build a sliding door with a screen in the rear that allows the ramp to stay open at night but easily allows breeze or privacy without raising ramp.