Pick the trailer (or slab) length and what your tiny house must hold. You get a floor plan drawn to scale, what does not fit, the square feet on the floor and in the loft, and the building code’s tiny-house minimums checked.
Your floor plan
Everything fits in 24 ft178 sq ft + a 54 sq ft loft · bathroom, kitchen, sofa, closet · queen in the loft
Quick answer: a tiny house on a 24 ft trailer, 8′ 6″ wide, has about 178 sq ft of floor inside 5″ walls, plus a 54 sq ft loft 7 ft long. That fits a bathroom across one end, stairs up to a queen loft over it, an 8 ft kitchen, a sofa and a closet, with a 36″ walkway. At 16 ft the sofa no longer fits. Type your length above for your own plan, drawn to scale, with the building code’s tiny-house minimums checked.
How to use the tiny house floor plan designer
- Type the length of the trailer deck (or the slab): 24′ or 7.3 m both work.
- Pick where you sleep: in a loft over the bathroom end, or on the ground floor across the far end. Then the bed size, and stairs or a ladder.
- Pick the bathroom, the kitchen length, the seating and a closet. Open Your house’s own numbers for the width, the inside height, the height under the loft and your walls.
- The plan updates as you type, drawn from above with the loft dashed. Copy link keeps it.
Tiny house sizes by trailer length
| Trailer | Floor inside | With a 7 ft loft | What fits (loft, stairs, bathroom) |
|---|---|---|---|
| 16 ft | 116 sq ft | 170 sq ft | kitchen, closet — no sofa |
| 20 ft | 147 sq ft | 201 sq ft | kitchen, sofa, closet |
| 24 ft | 178 sq ft | 232 sq ft | kitchen, sofa, closet |
| 28 ft | 208 sq ft | 262 sq ft | kitchen, sofa, closet |
| 32 ft | 239 sq ft | 293 sq ft | kitchen, sofa, closet |
8′ 6″ wide outside, 5″ walls, 11 ft inside at the loft end, 6′ 8″ under the loft, a bathroom with a shower, a composting toilet and a sink, and an 8 ft kitchen.
The rules behind the plan
How wide and how tall: the road
On US highways a trailer may be 102″ (8′ 6″) wide (23 CFR 658.15); wider needs a permit each time it moves. Height is each state’s rule, from 13′ 6″ to 14′ (FHWA). Take away the trailer deck and the floor and roof, and what is left is your inside height.
The code’s tiny-house minimums (IRC Appendix AQ)
- A tiny house is 400 sq ft of floor or less, lofts not counted.
- Living space and hallways at least 6′ 8″ high; bathrooms and kitchens 6′ 4″. A loft may be lower.
- A loft at least 35 sq ft and 5 ft in every direction, and any part under 3 ft high does not count.
- Stairs to a loft at least 20″ wide below the handrail, risers 7–12″, each tread at least 20″ less four-thirds of the riser. A ladder 12″ wide, at 70–80°.
- A loft guard 36″ high, or half the loft’s height if that is less.
Appendix AQ is part of the International Residential Code, for tiny houses on a foundation; a tiny house on wheels may be registered as a trailer or RV instead. Ask your local building department which rules yours falls under.
Room to move
Things that face each other keep a 36″ walkway, and the finder tries for 42″ in front of the kitchen, NKBA’s work aisle for one cook. Kitchen cabinets are 24″ deep, a sofa 38″, a dinette 62 × 24″. The bathroom keeps the code’s fixture minimums: 15″ each side of the toilet’s centre, 21″ in front, a 30 × 30″ shower.
Sitting up in the loft
Sitting up takes about 0.52 × your height above the mattress (Pheasant, Bodyspace). With 11 ft inside, 6′ 8″ under the loft and a 6¼″ loft floor, the loft is 45¾″ high: on an 8″ mattress, a 5′ 9″ person just sits up.
Worked examples
24 ft, a queen loft with stairs. Everything fits: 178 sq ft plus a 54 sq ft loft. The stairs take 9 risers of 9½″ and 58″ of floor; the kitchen has 44″ in front of it.
16 ft, the same wish list. 116 sq ft: the kitchen and closet fit, but not the sofa. A ladder takes 28″ of floor instead of 58″, but the sofa’s 38″ depth still leaves no 36″ walkway beside the kitchen.
24 ft with only 10′ 4″ inside. The loft is 37¾″ high: it still counts as a loft (over 3 ft), but it is for lying down, 6″ short of sitting up.
24 ft with the bed on the ground floor. No stairs, no loft: the queen goes across the far end, and everything fits in the 178 sq ft.
Common tiny house layout mistakes
- Measuring the trailer, not the inside. 5″ walls take 10″ off the width and the length. An 8′ 6″ house is 7′ 8″ inside.
- A loft you cannot sit up in. Under 3 ft the code does not count it, and a thick mattress eats what is left. Decide the loft height from the tallest sleeper.
- Stairs as an afterthought. Legal stairs to a 7 ft-high loft take about 5 ft of floor. A ladder takes 2 ft, but is harder to climb every night.
- A sofa facing the kitchen. A 38″ sofa and 24″ cabinets leave less than a 36″ walkway in an 8′ 6″ house. Put them end to end.
- Forgetting the door. It needs its own stretch of wall, clear of the kitchen and the stairs.
Bigger than a tiny house? The free 2D room planner draws any room to scale, and the RV & van layout designer does the same for a camper van.
Plan it freeRead next
- Tiny house living hacks that maximize every inch
- Small camper interior ideas for cozy living
- RV interior remodel ideas
Tiny house floor plan questions
How big is a tiny house?
The building code’s Appendix AQ calls a house of 400 sq ft of floor or less, lofts not counted, a tiny house. On a trailer, 8′ 6″ wide, that is about 116 sq ft inside at 16 ft, 178 sq ft at 24 ft and 239 sq ft at 32 ft, plus the loft.
How wide can a tiny house on wheels be?
102″ (8′ 6″) on US highways, the federal limit for vehicles (23 CFR 658.15). Wider needs a permit to move.
How tall can a tiny house on wheels be?
Each state sets it: from 13′ 6″ to 14′ (FHWA). The trailer deck, the floor and the roof all come off that before you reach the inside height.
What is the minimum size for a tiny house loft?
35 sq ft and at least 5 ft in every direction (IRC Appendix AQ), counting only the part at least 3 ft high. A queen mattress, 60 × 80″, lies across an 8′ 6″ house in 5 ft of loft; 7 ft leaves room to climb in.
How much headroom do you need in a tiny house?
6′ 8″ in living space and hallways, 6′ 4″ in bathrooms and kitchens, and a loft may be lower (IRC Appendix AQ). To sit up in a loft bed you need about half your height above the mattress.
What is a good tiny house layout?
A common one: the bathroom across one end with the sleeping loft over it, stairs up from the kitchen side, and the living space and door in the middle. The designer tries every order of the kitchen, seating and closet along the two walls and keeps a 36″ walkway.