[BLDG-SIM] LEED Core&Shell simulation and lighting

Thomas White twhite at glumac.com
Tue Oct 31 15:46:46 PST 2006

We ran into a similar question on a LEED C&S project in Seattle. We submitted a CIR to USGBC to allow for energy savings, after the construction, for a TI build-out to code. In our case, the lighting power density would, by Seattle code, be less than the LPD for ASHRAE code. Because the maximum LPD would be code-required, and because this LPD is less than the ASHRAE standard, the savings was allowed.  Here is the text of the CIR and subsequent ruling.
CIR submission:
We are performing energy modeling for [Seattle] Core & Shell ...projects according to the requirements for version 2.1 of the LEED-CS Rating System. Our question pertains to future tenant improvements for the lighting systems. 
Since it is a tenant improvement, the future lighting system is not currently being designed. However, we propose that the lighting power densities in the Design Energy Cost model be set to Washington State Energy Code (WSEC) maximum allowable values. The tenants will have to meet the WSEC for the lighting design. Since these lighting levels are lower than those in ASHRAE 90.1-99, the building will see additional energy savings over the ASHRAE code.
The Energy Cost Budget will be modeled to ASHRAE 90.1-1999 following the space-by-space method. This approach will also keep from mixing and matching between ASHRAE and state code for the baseline model. 
We believe that using the WSEC for the lighting design would be a reasonable approach. If the lighting design had been completed by the design group, the lighting levels would be less than or equal to the WSEC in order to be compliant. Therefore, the WSEC maximum lighting power density would represent the most conservative design to be installed after the tenant improvements are complete. 

If our proposal is accepted, the following lighting power density values would be used:

Space Type           ECB        DEC

Retail                  1.9 W/sf    1.5 W/sf

Office-open plan        1.3 W/sf    1.0 W/sf

Main Floor Lobby        1.8 W/sf    1.2 W/sf

Other Elevator Lobbies  1.8 W/sf    0.8 W/sf


This is acceptable. The Core and Shell Energy Modeling Guidelines are developed with ASHRAE 90.1 as the referenced standard for both the Energy Cost Budget (ECB) and the Design Energy Cost (DEC) to ensure a minimum standard for the lighting power density in spaces that are outside of the control of the owner/developer. Because tenant buildout (not in the control of the owner/developer) will be required by local or regional regulations


Thomas J. White, P.E.
Lead Engineer, Energy Services
LEED(R) Accredited Professional
503.345.6246  |  twhite at glumac.com
320 SW Washington, Suite 200
Portland, OR 97204-2640
T. 503.227.5280   F. 503.274.7674 
http://www.glumac.com <http://www.glumac.com/> 
-----Original Message-----
From: BLDG-SIM at GARD.COM [mailto:BLDG-SIM at GARD.COM]On Behalf Of Chris Jones
Sent: Tuesday, October 31, 2006 2:41 AM
Subject: [BLDG-SIM] LEED Core&Shell simulation and lighting

I am a bit fuzzy on how to define the design and budget building lighting loads for LEED C&S.  With most core and shell projects, the lighting is minimal - waiting for the TI to design the lighting.  If that is the case with a specific C&S project, then I assume the lighting is not fully designed then I assume that table 11.3.1 1(c) applies:
(c) When the energy cost budget method is applied to buildings in which
energy-related features have not yet been designed (e.g., a lighting system),
those yet-to-be-designed features shall be described in the proposed design so
that they minimally comply with applicable mandatory and prescriptive
requirements from Sections 5 through 10. Where the space classification for a
building is not known, the building shall be categorized as an office building.

In this case, then it would seem that there is no advantage to trying to design an efficient Core and Shell lighting design?  Any thoughts greatly appreciated.

Chris Jones
14 Oneida Avenue
Toronto, ON M5J 2E3.
Tel.  416-203-7465
Fax. 416-946-1005


You received this e-mail because you are subscribed 

to the BLDG-SIM at GARD.COM mailing list.  To unsubscribe 

from this mailing list send a blank message to 


You received this e-mail because you are subscribed 
to the BLDG-SIM at GARD.COM mailing list.  To unsubscribe 
from this mailing list send a blank message to 
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.onebuilding.org/pipermail/bldg-sim-onebuilding.org/attachments/20061031/ff44a03d/attachment-0002.htm>

More information about the Bldg-sim mailing list