Cost analysis supports updating the codes

Home Innovation Research Labs, an independent subsidiary of the National Association of Home Builders, released a report on the cost analysis for multifamily buildings — Estimated Costs of the 2018 ICC Code Changes for Multifamily Buildings — which shows minimum cost impacts for typical multifamily buildings ranging from $2,500 for a small two-story multifamily project to $25,000 for a larger five-story project. The higher costs are primarily due to significant changes involving elevators and wind load design. The small townhouse was 2,500 square feet with an approximate valuation of $300,000; the large project was a five-story, apartment project with an enclosed underground parking garage measuring 462,600 square feet valued at approximately $67 million.

Using a similar methodology to its studies for the International Residential Code, Home Innovation looked at four multifamily buildings ranging from a two-story, 24-unit building to a five-story, 167-unit building. Two of the four buildings included public spaces such as community or fitness rooms, leasing offices or retail spaces. The study also looked at a typical four-story townhouse. The study examined a list of 26 code changes affecting multifamily construction that were approved for incorporation into the 2018 International Codes. The changes affect the International Building Code (IBC), the International Energy Conservation Code (IECC), the International Fire Code (IFC) and the International Mechanical Code (IMC). The expected cost impact of these code changes on construction practices and materials was estimated — cost estimates are aggregated in ranges of high to low based on various methods or components that might be used to comply with the code.

The Baseline metrics for five representative multifamily buildings built to the 2015 IBC, IECC, IFC and IMC were defined in order to determine the cost impact resulting from the revisions approved for the 2018 International Codes. Elevations and floor plans for these reference buildings are provided in Appendices C through G. The reference buildings define a starting point for the analysis of the cost impact to a builder resulting from adoption of the 2018 International Codes (relative to the 2015 IBC/IECC/IFC/IMC baseline).

Click here to view or download the report.