New state construction and major renovations. In 2001, Minnesota required the Departments of Administration and Commerce to develop sustainable building design guidelines (Minn. Stat. 16B.325) for new state buildings. These guidelines were mandatory for new buildings funded fully or in part by state bond money after January 1, 2004. The guidelines required that projects exceed the January 2004 state energy code by 30 percent.
Onsite renewable energy. In 2008, it was amended that managers must supply 2% of a building's total energy use with on-site wind and sun power or supply a full cost and carbon analysis explaining why renewables would not be cost effective. Noncompliance results in loss of any further state money for the project.
Off-site renewable and clean distributed generation systems. The guidelines also contain a rule requirement that building operators must select new equipment and appliances that meet Energy Star criteria. This stipulation is meant to operate in addition to the 30 percent energy use reduction attributable to the building itself. Other portions of the guidelines address additional aspects of sustainability, such as water management, indoor air quality, and waste reduction.
In April 2009, this law was amended by H.F. 380 appropriations bill to also apply to major renovations funded from the bond proceeds fund after January 1, 2009. Major renovations are defined to at a minimum encompass more than 10,000 square feet or involve the complete replacement of a mechanical, ventilation, or cooling system. $1 million was appropriated to H.B. 16.307 to replace existing state buildings with more energy and carbon efficient buildings.
Sustainable Building 2030. In May 2008, Minnesota enacted S.F. 2706, directing the Commerce Commissioner to contract with the Center for Sustainable Building Research at the University of Minnesota and grant $500,000 annually to coordinate and implement the development of new Sustainable Building 2030 performance standards. At least $350,000 of this must be spent for subcontracts to undertake technical projects. These standards are designed to achieve energy consumption reductions of 60 percent in 2010 (2003 baseline), increasing 10 percent every five years towards an ultimate target of 90 percent in 2025. Buildings entering schematic design after August 2009 must apply SB2030 standards.
In 1999 the Minnesota legislature transferred authority for adopting the state's energy code from the Department of Commerce to the Department of Administration Building Codes and Standards Division. Additional changes to the code may be mandated by the state legislature. Anyone can submit changes to the Energy Division staff for consideration. The Building Codes and Standards Division will review new model codes for adoption with amendments appropriately on a three year cycle. The Administrative Procedure Act provides procedures that require a formal public hearing only if requested by 25 or more individuals.
In 1979 individual counties outside of the seven-county Minneapolis/St. Paul area and incorporated cities with populations of less than 2,500 were given the option of enforcing a statewide building code. Many elected to have no enforcement within their area. Currently enforcement occurs for about 80 percent of the population base; approximately 20 percent of the population has no enforced energy code.
Plans and specifications must be submitted. In addition to the REScheck list, plans must also show the location of interior air barriers, vapor barriers, and wind wash barriers as well as air sealing requirements. Some plans must be stamped by a registered design professional as required by the state statute. The code establishes minimum submittal requirements concerning R-values, equipment efficiencies, and lighting components. Field inspections are required prior to the issuance of a Certificate of Occupancy. Field inspections are performed as part of the normal building inspection process.
For buildings not inspected by the State Department of Administration, interpretations are made at the local level. Disagreements may be forwarded to a local appeals board. The Department of Commerce is frequently asked for an opinion, but has no enforcement authority.
All residential structures in areas that have adopted and enforce the code are required to comply with the state residential energy code. The compliance pathways are those outlined in the MEC.
All commercial structures and high-rise residential buildings in areas that have adopted and enforce the code are required to comply with the state commercial energy code using one of three compliance paths. Requirements to submit plans for review and requirements for stamping by a registered engineer or architect are the same as those required in the MEC.
A state law was enacted in 1975 to require building design and construction standards consistent with the most efficient use of energy. In response, an energy code became effective on January 30, 1976, as part of the state building code.
The energy code was revised in 1977 and 1978 to incorporate ASHRAE/IES Standard 90-75 requirements.
The energy code was revised in 1984 to adopt the 1983 MEC and the insulation provisions of the HUD Minimum Property Standards for residential construction (including foundation wall insulation for residential buildings).
A 1991 revision adopted the 1989 MEC. Statutes were enacted in 1991 setting higher goals for the energy code. One statute required that the energy code requirements for commercial buildings be at least as energy efficient as ASHRAE/IESNA 90.1-1989. Another statute specified that the lighting standards be at least as energy efficient as the "current" requirements for new federal buildings (10 CFR Part 435). (Note: this statute was repealed in 1999 with the legislation discussed below).
In 1991, code amendments were related to the air tightness of buildings, wind wash barriers, and other provisions to ensure performance of installed thermal insulation and durability of structural elements. Code revisions adopted June 1994 provided for minimum criteria for residential buildings (termed Category 2), and an optional higher criteria (termed Category 1). All commercial buildings, and residential buildings over three stories in height, were required to meet a state amended version of ASHRAE/IESNA 90.1-1989. One- and two-family dwellings, and multi-family residential buildings three stories or less in height, were required to meet a state code based on the 1992 MEC.
Changes were adopted for the commercial building energy code (Minnesota Rules Chapters 7676 and 7678) on November 4, 1997. These revisions, which became effective July 20, 1999, provided minimum criteria for energy efficiency standards for commercial buildings.
In 1999, legislation (Laws of Minn. 1999, Chapter 135) transferred the authority for rule-making to the Minnesota Department of Administration, Building Codes and Standards Division. Laws of Minnesota 2000 Chapter 407 gave builders an alternative to the new rules: instead of following Chapter 7672, they could meet the provisions of Minnesota Rules 7670 (the energy code adopted in 1994) that apply to Category 1 buildings, plus some additional requirements regarding ventilation and heating and exhaust systems.
New energy code rules went in effect for residential building permits beginning April 15, 2000. They applied to detached single-family and two-family dwellings (classified as Group R, Division 3 Occupancies). The 2000 Minnesota legislature also gave builders an alternative to the new rules: instead of following Chapter 7672, they could meet the provisions of Minnesota Rules 7670 (the energy code adopted in 1994) that apply to Category 1 buildings, plus some additional requirements regarding ventilation and heating and exhaust systems. For remodeling and multi-family homes, the builder must comply with either Chapter 7672 or 7670. (If 7670 rules are followed, the additional ventilation and other mechanical requirements do not apply.)
After authority over energy codes was transferred to the Building Codes and Standards Division (within the Construction Codes and Licensing Division) in the Department of Labor & Industry, significant effort was made to transition the Minnesota building community from a purely state-developed code to one aligned more closely to the model codes. In 2008, after seven and a half years, the state adopted new residential and commercial energy codes based on the 2006 IRC and ASHRAE 90.1-2004, respectively. Officials hope to streamline this process in the future and update the state codes more frequently.
On June 1, 2009, the 2009 Minnesota State Building Code became effective. The new residential energy code (Chapter 1322) has been simplified to the point that in virtually all cases a REScheck-like program is not needed to show code compliance. The code now simply requires minimum R-values and maximum U-factors for building components without regard to square footage of those elements. A REScheck for the new Minnesota code is not currently available. Other alternatives are listed in the code at Part 1322.1102.
COMcheck is not yet available for the new commercial energy code (Chapter 1323), but commercial building envelope and lighting compliance can be readily determined by available tools. The envelope requirements of the new commercial energy code are not difficult to determine from the two tables (one for northern and the other for southern Minnesota) in Part 1323.0550. The lighting requirements of the code are identical to ASHRAE 90.1-2004, with the exception of exterior building grounds and parking lot lighting (Part 1323.0944). To demonstrate lighting compliance, simply start COMcheck and select "Code: 90.1 (2004) Standard" for all but building grounds and parking lot lighting.
In 2009, Minn Chapter Law 110 established Sustainable Building 2030. The Center for Sustainable Building Research and the University of Minnesota is developing SB2030 performance standards.