How do you find the usable space in a tiny house?
FYI for your tiny house design – Everyone does things differently in the DIY world, so telling you how much space is going to be inside your tiny house is very complicated. Here are some of the general measurements and averages you will find in tiny houses.
| Width 8 1/2 max = Width of outer walls – 8 1/2 feet | Living dimensions average around 7 1/2 feet inside (12 inches for walls) |
| Height 13 1/2 max = Ground to top of roof – 13 1/2 feet (162 inches) | Living dimensions average somewhere between 9.5 feet – 11.8 feet inside ( 48 inches deck, floor and roof – 20 inches deck, floor and roof ) Allow for the loss of the raised fenders in the floor plan in your design. |
| Length 12-39 max = Width of outer walls + the length of the trailer tongue (See below) | Living space for a trailer that is 39 foot long is around 31 feet inside |
Stick your trailers tongue out – A trailer tongue can add an additional 3 1/2 feet and up to 7 feet to the overall length of the trailer dependent on the trailers design. Length of a trailer is generally advertised as the exact size of the bed. Often the V of the tongue and fenders are excluded from the trailers advertised length.
The trailer you select can change your usable living space before you begin building – Knowing how trailer lengths are measured and how they can vary based on who sells it or what it was originally designed for. Most trailer manufactures measure the usable space not actual length and width. The most common causes of measurement confusion;
- Enclosed V nose cargo trailers – Measures the forward extension V on the trailers tongue. With the cargo enclosure removed the trailers usable area is again measured like any other trailer. A reduction of 2 feet or more.
- Fifth wheels – Fifth wheels and goose neck trailers used for a tiny house are often measured to include the area covering the fifth wheel. If they are measured in this way you loose much of the vertical space available on standard pull trailers of when both are measured properly.
- Travel trailers and other trailers that utilize pull outs or extend the usable space onto the tongue or a rear deck. When dismantled the actual usable space is sometimes dramatically reduced.
- Used trailers are often sold with incorrect measurements. They may claim the trailers length is from hitch tip to the tail end instead of usable space. Always measure the usable space yourself or you could pay far too much for a smaller trailer.
- Support of the extended or retracted pull out is needed for long term weight distribution while parked or traveling.
- Weather seals need to withstand long term exposure to elements while parked or traveling
- Locking pull out extensions for travel is needed. Take into account everyday g-force stresses associated with common driving with a load (see minimums in the diagram below)
| Forward acting forces | Backward acting forces | Sideways acting forces |
| 0.8 g | 0.5 g | 0.5 g |
What choices you make affect your final measurements – Some things may take less time to install, come free or cheap only to consume precious space needed inside your tiny house. Here are some things to monitor carefully or avoid completely:
- Cedar siding can reduce your living space by 6 inches or more.
- Using sheet rock or wood interior siding
- Roof eves, gutters or downspouts or shutters designed for traditional houses
- Secondary insulation needed to repair initial improper insulation methods
- Some bridges marked XX feet xx inches could be inches less
- Pay attention to overpasses-bridges and street signs – No trucks = less then 13.6 feet
- Height or clearance markings measure from the lowest point in a ROAD, the shoulder clearance could be less
