According to ASHRAE 90.1-2010, paragraph 9.6.2, an additional interior lighting power is allowed for the following categories:

a) Decorative lighting (up to 1W/ft2)
b) Merchandise lighting
c) For some space types with additional controls.

Table 5 of LEED V4 IDC Reference Guide, confirms that "the baseline building must be modelled equal to what has been designed or up to the lighting allowance from ASHRAE 90.1, Section 9.6.2, whichever is less".

Question: Can we use a combined figure for the baseline AND additional lighting? a+b+c = total allowance.

Or, do we have calculate the three different categories individually, e.g. calculate a) the baseline decorative lighting to be what has been designed or up to the allowance (which ever is less), then calculate b) the baseline merchandise lighting to be what has been designed or up to the allowance (which ever is less), etc.?

In short we have a situation where if we consider each of the lighting categories separately the decorative lighting alone is lower than the allowance, and the merchandise lighting alone is higher than the allowance, however, when added together the combined figure a) + b) is compliant with the total allowance, is this acceptable, or does each individual lighting category need to be compliant on its own?