6x12
Target Box
DIY Trailer Plan
Build a Lightweight Wood-Frame Camper for $4,500
A stripped trailer frame, a simple 6x12 stick-built box, and only the systems that matter: door, window AC, mini fridge, wet shower, toilet, bed, and kitchen sink.
$4.5K
Hard Cap
2x2
Wall Framing
120V
Shore Power First
The Direction
Do Not Build a Tiny House
The budget works only if this is treated like a simple travel trailer shell, not a residential tiny home. Keep the structure rectangular, keep the systems portable, and spend money on weatherproofing, tires, lights, and electrical safety before finish details.
Front / Tongue EndKeep batteries, water jugs, and storage low and slightly forward.
Wet Bath30x30 or 32x32 shower pan, FRP walls, curtain, portable toilet.
Door + ACEntry door on passenger side. Window AC framed through wall with exterior support.
Kitchen WallSink, pump, jugs, mini fridge under counter, microwave on shelf.
Rear Bed48-54 inch bed platform across the back, with storage below.
Simple floor plan: front utility/wet bath, middle entry and kitchen, rear bed. Heavy items stay low and forward of the axle.
Use This Baseline
- Trailer: one stripped frame, inspected before the build starts.
- Body: 6 ft wide by 12 ft long, about 6 ft interior standing height if the frame can carry it.
- Frame: 2x2 walls, 1x3 or 2x2 roof bows, 3/4 inch plywood floor.
- Skin: 1/4 inch plywood exterior with sealed seams and metal trim, or budget metal panels where practical.
- Systems: 120V shore power first. Solar can be added later after the camper is dry and usable.
Budget
$4,500 Material Target
These are target numbers, not guaranteed store quotes. The build stays under the cap by using used/salvage parts for the door, window, fridge, microwave, sink, and toilet where possible.
| Category | Target Spend | Notes |
|---|---|---|
| Trailer frame rehab | $400 | Paint, bolts, basic lights, wiring repair, coupler check. |
| Subfloor | $350 | 3/4 inch plywood, sealant, adhesive, bolts, undercoat. |
| Wall and roof framing | $450 | 2x2, 1x3, blocking, screws, construction adhesive. |
| Exterior shell | $700 | Thin plywood skin, housewrap, flashing, corner trim, paint. |
| Insulation and interior panels | $500 | 1 inch foam board plus thin plywood or luan. |
| Door and window | $450 | Buy used if possible. New RV doors can break the budget. |
| Appliances | $350 | Used mini fridge, cheap microwave, existing window AC if safe to mount. |
| Kitchen and plumbing | $300 | Sink, faucet, 12V pump, jugs, hose, drain, portable gray tank. |
| Wet bath and toilet | $650 | Shower pan, FRP, curtain, portable/cassette toilet. |
| Electrical | $450 | Shore inlet, GFCI, breaker/disconnect, outlets, lights, wire. |
| Flooring, paint, sealants, mistakes | $700 | The catch-all line that prevents fantasy budgeting. |
| Total target | $4,250 | Leaves about $250 of breathing room. |
Materials
Home Depot Style Shopping List
Shell
- 3/4 inch plywood for floor
- 2x2 lumber for wall studs and blocking
- 1x3 or 2x2 lumber for roof bows
- 1/4 inch plywood or luan for exterior/interior panels
- Foam board insulation
- Butyl tape, flashing tape, exterior sealant, paint, primer
- Aluminum or galvanized corner trim and drip edge
Interior Systems
- 30x30 or 32x32 shower pan
- FRP wall panels for wet bath
- Portable or cassette toilet
- Small bar sink and faucet
- 5-7 gallon fresh water jugs and gray water tote
- 12V demand pump or simple manual pump
- Shore power inlet, GFCI outlet, lights, small breaker box
Window AC warning: only mount a window unit through the wall if the unit can breathe exactly as the manual requires. Side vents cannot be buried inside a framed wall. If the Costco unit is a recalled Midea U/U+ model, verify the model and drain fix before building around it.
Sequence
Build Order
01
Pick One Frame
Choose the best trailer frame. Inspect welds, axle, tires, suspension, coupler, lights, title, and brake requirements before buying materials.
02
Deck It
Bolt down a sealed 3/4 inch plywood floor. Paint or undercoat the underside before walls go up.
03
Frame the Box
Build simple 2x2 walls flat, raise them, brace square, then frame the roof. Avoid curves and complex corners.
04
Place Openings
Frame the door, one window, and the AC opening before skinning. Add real blocking for hinges, latches, and AC support.
05
Make It Dry
Exterior skin, tape, flashing, trim, paint, and roof sealing happen before interior finish. Water is the main enemy.
06
Add Systems
Install shore power, lights, pump, sink, wet bath, toilet, fridge, microwave, and bed platform. Add solar later if desired.
Borrowed Wisdom
Plans Worth Reviewing
The most useful existing plans are not exact copies of this build, but they solve pieces of it: small trailer balance, light wood bodies, indoor kitchens, and compact layouts.
- Teardrops n Tiny Travel Trailers resources - plan library with Generic Benroy, The Widget, Campster 12, Wanderer, and trailer balance resources.
- TnTTT Foamies forum - useful for lightweight trailer thinking even though this plan uses wood framing.
- AP report on Midea U/U+ AC recall - check your Costco AC model before framing a permanent wall opening.
The DIY Set
Three Ways To Build Off-Grid Shelter
Pick the path that fits your budget and skills — a cheap wood-frame trailer, a serious 40-foot container home, or the AC recall check you need before you frame any window unit into a wall.
DIY Trailer · $4.5K
Lightweight 6x12 wood-frame camper on a stripped trailer frame — door, window AC, wet bath, kitchen, and bed, under budget.
DIY Conex · $31K
A 40-foot high-cube container turned into a real small home: bedroom, wet bath, kitchen, and a living zone.
Midea Recall
Before you frame a window AC into a wall, check the Midea U/U+ recall — refund rules, cord-cut proof, and the hotline.