Generator Req'd for Low-Rise Bldg?

[WoodrowJWeen]

I'm working on a 5 story hotel project which will use battery packs for egress lighting. The city reviewer has come back and said that we need to add a generator to supply the elevators so they can be used as an "accessable means of egress". They are citing IBC (International Building Code) section 1007.2.1 and 1007.4. No other electrical engineers I know have ever heard of this being a requirement for a low rise-building (less than 75 feet to the highest occupied floor). Anyone run into this lately?

 

[jbelectrical]

For buildings classified as high-rises, we are always required to provide standby power for at least one elevator.

For a low-rise building such as the one you describe, the only loads that have ever been required to be served by the generator are: emergency egress lighting (If not using battery packs), fire alarm control panels, telecommunications systems, fire pumps, etc. Never an elevator, though.

 

[DonPhillips]

My guess is the stairwell(s) is not designed as the accessible egress so the elevator would make sense. I would have a discussion with the architect to see how the accessible means of egress can be econimally provided.

Don Phillips

http://worthingtonengineering.com

 

[rbulsara]

I think a 5 story building would be a high rise regardless of its height. The 75 feet height rule is there so that someone won't build a 4-20 ft story buildig and try to get away without complying with high rise requirements.

 

[DonPhillips]

It may not be a high-rise since the 75' rule is the level above the exit discharge. With 8' ceiling heights, 3' plenums, 24" girders, and 6" slabs, I get a story height of 13.5'. Rounding to 14.5' (I seem to remember the project I was on in 1989 had 27-14.5' stories) it is possible the fifth floor is only 58' above the exit discharge. If the machanical penthouse is counted, you may have 72.5'.

Don Phillips

http://worthingtonengineering.com

 

[EEJaime]

The provisions of Chapter for of the UBC or in my case the California Building code, indicate that a high rise building includes all buildings with a habitable floor more than 75' above the lowest exit discharge level that provides fire personnel entry and communication with the rest of the building. With specific exceptions for parking garages, grain elevators, steeples,jails, etc....

A hotel which might have a first floor of perhaps as much as 18' floor-to-floor height for the lobby floor and 13' to 14' floor-to-floor heights for the remainder, may still not be a high rise by Building Code definitions. However, we have a local municipality near here in Riverside, Ca. which has a local ordinance deeming any structure more than TWO stories high as being a high rise structure. So as with all things code, check with the local AHJ before proceeding with the design.

The only copy I have here of the IBC is an old 2000 version, but it states:

SECTION 403 HIGH RISE BUILDINGS
Section 403.1 "Applicability-The provisions of this section shall apply to buildings having occupied floors located more than 75 feet, (22 860 mm), above the lowest level of fire department vehicle access."

Again there are several exceptions listed for airports, parking garages, hazardous occupancies, etc....

Best of luck,
EEJaime

 

[DonPhillips]

Similar verbiage in the 2003 and 2006 IBC.


Don Phillips

http://worthingtonengineering.com