Subp. 3.
Applicability.
A.
Additions, alterations, renovations, or repairs. Additions,
alterations, renovations, or repairs to an existing building, building system,
or portion of a building shall conform to the provisions of this code as they
relate to new construction without requiring the unaltered portion of the
existing building or building system to comply with this code. Additions,
alterations, renovations, or repairs shall not create an unsafe or hazardous
condition or overload existing building systems. An addition shall comply with
this code if the addition alone complies or if the existing building and
addition comply with this code as a single building. Attic insulation shall not
be installed unless accessible attic bypasses have been sealed. An attic bypass
is any air passageway between a conditioned space and an unconditioned attic.
Exceptions: The following are excepted from this
part provided the energy use of the building is not increased:
1. Storm windows installed over existing
windows.
2. Glass only replacements
in an existing sash and frame.
3.
Existing ceiling, wall, or floor cavities exposed during construction provided
that these cavities are filled with insulation.
4. Construction where the existing roof,
wall, or floor cavity is not exposed.
5. Reroofing and residing.
6. Replacement of existing doors that
separate conditioned space from the exterior do not require the installation of
a vestibule or revolving door; provided that an existing vestibule that
separates a conditioned space from the exterior shall not be removed.
7. Alterations that replace less than 50
percent of the luminaires in a space, provided that the alterations do not
increase the installed interior lighting power.
8. Alterations that replace only the bulb and
ballast within the existing luminaires in a space, provided that the alteration
does not increase the installed interior lighting power.
9. Insulation R-value, air barrier, and vapor
retarder requirements are not applicable to existing foundations, crawl space
walls, and basements in existing dwellings or dwelling units when the
alteration or repair requires a permit if the original dwelling or dwelling
unit permit was issued before June 1, 2009.