Log Cabin Rule in Indiana Protects the Right of the DIYer to Build Own Home

The State of Indiana allows counties to establish building codes. However, section IC 36-7-8-3 (d) specifically excludes those codes from applying to "private homes that are built by individuals and used for their own occupancy." This is known as the Log Cabin Rule.

Note, however, that the law most likely will not protect tiny homes on wheels, which are generally considered RVs.

In addition, counties sometimes try to fight the law even for homes on foundations: http://indianahomestead.com/log-cabin-rule/

Indiana State Code IC 36-7-8
Chapter 8. County Building Department and Building Standards
IC 36-7-8-1
Application of chapter
Sec. 1. This chapter applies to all counties.
As added by Acts 1981, P.L.309, SEC.27.

IC 36-7-8-2
Establishment of buildings department
Sec. 2. The legislative body of a county may, by ordinance, establish a county department of buildings, with an office of building commissioner and inspectors.
As added by Acts 1981, P.L.309, SEC.27.

IC 36-7-8-3
Establishment of building, heating, ventilating, electrical, plumbing, and sanitation standards; ordinances
Sec. 3. (a) The legislative body of a county having a county department of buildings or joint city-county building department may, by ordinance, adopt building, heating, ventilating, air conditioning, electrical, plumbing, and sanitation standards for unincorporated areas of the county. These standards take effect only on the legislative body’s receipt of written approval from the fire prevention and building safety commission.
(b) An ordinance adopted under this section must be based on occupancy, and it applies to:
(1) the construction, alteration, equipment, use, occupancy, location, and maintenance of buildings, structures, and appurtenances that are on land or over water and are:
(A) erected after the ordinance takes effect; and
(B) if expressly provided by the ordinance, existing when the ordinance takes effect;
(2) conversions of buildings and structures, or parts of them, from one occupancy classification to another; and
(3) the movement or demolition of buildings, structures, and equipment for the operation of buildings and structures.
(c) The rules of the fire prevention and building safety commission are the minimum standards upon which ordinances adopted under this section must be based.
(d) An ordinance adopted under this section does not apply to private homes that are built by individuals and used for their own occupancy.
As added by Acts 1981, P.L.309, SEC.27. Amended by P.L.8-1984, SEC.125.

Link to the official code: http://www.in.gov/legislative/ic/2004/title36/ar7/ch8.html