Small is a strategy

A small home is cheaper to build, heat, cool and power. It also uses fewer materials and less land. That makes every other budget easier.

But small homes come in very different forms. They differ in cost, in how they are built, in how long they last, and in whether you are allowed to live in them full-time.

This lesson compares six types. None is best everywhere. The right one depends on your brief.

Tiny house on wheels and cabin

Tiny house on wheels. A small house built on a trailer.

  • Can be moved, and is often built in a shop.
  • Road limits cap its size. On major highways the legal width is 8.5 ft (2.6 m), and wider loads need a special permit.
  • Many are built to recreational vehicle (RV) standards. Local zoning may treat it as an RV and limit full-time living.

Cabin. A small, simple house on a fixed foundation, often wood-framed.

  • Familiar to builders and inspectors.
  • Can be built in stages and added to later.
  • Older or rustic cabins are often poorly insulated and drafty.

Small conventional and modular

Small conventional home. A small house built on site to the local building code, like any other house.

  • Easiest to permit, insure, finance and sell.
  • Can be the most expensive per square foot, because fixed costs like the foundation, kitchen and bathroom are spread over less space.

Modular home. Built in sections in a factory, trucked to the site, and set on a foundation.

  • Factory building is fast and less affected by weather.
  • Modular homes are built to state or local building codes. Manufactured homes are different: they follow a federal (HUD) code instead.
  • Needs road access for large trucks and often a crane.

Container and earth-sheltered

Shipping container home. Built from steel shipping containers, about 8 ft (2.4 m) wide.

  • Strong boxes that are quick to place.
  • Steel conducts heat well, so walls need a lot of insulation, which eats interior width.
  • Cold steel walls can drip with condensation: water from indoor air that turns to liquid on a cold surface.
  • Cutting openings for doors and windows changes how the box carries load. That is engineering work.

Earth-sheltered home. Partly buried in a hillside or covered with soil.

  • Soil evens out temperature swings, so it can be milder inside in summer and winter.
  • Soil is heavy and wet. Walls and roof need careful structural design and waterproofing. Mistakes are expensive to fix.

Which type is it?

Sort it

Which home type does each statement describe best?

  1. Inspected in the factory, often with fewer weather delays
  2. Waterproofing and heavy soil loads need careful engineering
  3. Cutting window openings changes how the walls carry load
  4. Built in sections in a factory and set on a foundation with a crane
  5. Zoning may treat it as an RV and limit full-time living
  6. Steel walls sweat with condensation unless well insulated
  7. Soil keeps the inside temperature steady through the seasons
  8. Road width and weight limits cap its size

The trade-offs side by side

Six small-home types drawn from above at the same scale. The trailer and container types are far narrower than the rest.
Text description

Six floor footprints seen from above, all at the same scale, with a 20 ft (6 m) scale bar. The sizes are examples, except the widths the lesson gives. From left: a tiny house on wheels, 8.5 ft (2.6 m) wide, the legal width on major highways, with a trailer hitch at one end; a cabin on a fixed foundation; a small conventional home built on site, the largest outline in the group except the modular; a modular home made of two factory sections joined down the middle; a shipping container home, about 8 ft (2.4 m) wide and long and narrow; and an earth-sheltered home with soil banked against three sides. A dashed square on the small conventional home shows 400 sq ft (37 m²), the size limit in the IRC tiny house appendix, not counting lofts.

Legality comes first

Before you fall for a type, ask whether you can live in it legally on your land.

  • Zoning rules decide what can be built where, how small a home can be, and whether an RV can be a full-time home.
  • Building codes decide how it must be built. The IRC, the model code for houses, has an appendix for tiny houses of 400 sq ft (37 m²) or less, not counting lofts. It only applies where your area has adopted it.
  • Insurance and loans can be hard to get for unusual types.

Check

Check your understanding

Your brief says: one person, low budget, must be legal full-time, and you may move in five years. Which question should you answer first?

Summary

  • Small homes lower every budget: energy, heat, water and money.
  • Six common types: tiny house on wheels, cabin, small conventional, modular, shipping container, earth-sheltered.
  • Each has real trade-offs in cost, comfort, durability and legality.
  • Check zoning and building codes before you choose.
  • Containers and earth-sheltered homes need structural engineering.

Next, you will see how any building stays standing, from the roof down to the soil.

Go deeper: cost per square foot can mislead

Kitchens, bathrooms, foundations, permits and utility connections cost about the same whether the house is big or small. So a small house often costs more per square foot than a big one, even though it costs less in total. Compare total cost and running cost, not just cost per square foot. A small home that is well insulated may also cost far less to run every year.

Finish up

Mark this lesson complete to track your progress. It is saved only in this browser.

Sources

  1. International Residential Code (IRC), including Appendix AQ, Tiny Houses, International Code Council
  2. Adoptable appendices in the International Residential Code for cob construction and tiny houses, International Code Council, Building Safety Journal
  3. Commercial Vehicle Size and Weight Program (federal 102-inch width limit), US Federal Highway Administration
  4. Building America Solution Center, US DOE and Pacific Northwest National Laboratory
  5. Building Energy Codes Program, US Department of Energy
  6. Insulation, US Department of Energy, Energy Saver (archived copy; the page was removed from energy.gov in mid-2026)

Spotted an error? See Corrections for how to report it.