Are Energy Code Upgrades Required with a Change of Occupancy?
Question: Does a change in occupancy or a change of use to an existing building subject it to comply with the Energy Efficiency Code of Chapter 13, of the Ohio Building Code (OBC) therefore requiring energy code upgrades including improvements to the building envelope?
Answer: Not necessarily. The Energy Efficiency Code of Chapter 13 of the OBC in turn references to ASHRAE 90.1 or the International Energy Conservation Code. The following code section occurs in the 2009 IECC which is referenced.
101.4.4 Change in occupancy or use.
"Spaces undergoing a change in occupancy that would result in an increase in demand for either fossil fuel or electrical energy shall comply with this code. Where the use in a space changes from one use in Table 505.5.2 to another use in Table 505.5.2, the installed lighting wattage shall comply with Section 505.5."
Basically, if the change of use results in more fossil fuel usage due to an upgraded mechanical system, or if electrical use will increase due to added power or lighting, and a new electrical panel is needed, either of these would trigger that the building would need to be brought up to code as far as energy compliance. The converse of this is also true, that is if the fossil fuels or electrical energy will not increase due to the change of occupancy, then the building is exempt from meeting the energy envelope requirements. (One can still add insulation, but it is no longer a prescribed amount for compliance.)
Not part II of the above, this refers to a change of use per Table 505.5.2 for lighting.
You will note that if you have a previous retail space, which has a 1.5 W/SF power allowance, to which you wish to put offices within that space, at 1.0 W/SF, the new office use would need to meet the 1.0 W/SF. Thus this case would meet the exception for energy code upgrades as well.
As a final note, if you have a space that was unheated and now it is planned to be a heated, cooled or conditioned space, it needs to meet the following section:
101.4.5 Change in space conditioning
"Any non-conditioned space that is altered to become conditioned space shall be required to be brought into full compliance with this code."
Hopefully these guidelines will help you in determining when an existing building would need to comply with the present energy conservation codes.