An addition not an addition but separate building?

[princeofpen]

IF an existing building is over the height/area calc and an increase in floorspace needed can it be added to using what code section? OR would the separate buildings on the same lot IE 4 walls with fire separated roof structure be the only way?

Currently proposed by design is 3 walls constructed added to existing building with a rated assembly of 2hrs between what was the existing building and addition.

Thoughts regarding your plan review/compliance path would be appreciated. POP

 

[steveray]

Firewall.....or they could add sprinklers......

 

[Frank]

Note the addition of an adjacent building separated by firewall makes teh existing building more noncompliant by reducing open perimeter.

 

[steveray]

Note the addition of an adjacent building separated by firewall makes teh existing building more noncompliant by reducing open perimeter.

Good call Frank!

 

[princeofpen]

Frank, Addition to the building will decrease it's open perimeter yes BUT it cannot be a compliance issue. 3403.1 regards the height and area of the existing building not being permitted to increase not open perimeter. IF that was the case no building would be able to increase. Addition of a fire wall isn't an option as well in my opinion. What we have here isn't an issue of maintaining fire areas to a given size in order to not sprinkler but rather a already non-sprinklered school that wishes to be larger.

My "opinion" whatever it's worth as plans examiner is that in order for the building to be "added" to would require separate buildings on the same lot with fire separations per T602 & T601, and separate structural walls for the building/addition.

Thoughts?

POP

 

[steveray]

We had a school that was 3X over the allowable H&A with the sprinklers it DID NOT have.....it now has sprinklers and 2 firewalls.....

Frank, Addition to the building will decrease it's open perimeter yes BUT it cannot be a compliance issue. 3403.1 regards the height and area of the existing building not being permitted to increase not open perimeter. IF that was the case no building would be able to increase. Addition of a fire wall isn't an option as well in my opinion. What we have here isn't an issue of maintaining fire areas to a given size in order to not sprinkler but rather a already non-sprinklered school that wishes to be larger. My "opinion" whatever it's worth as plans examiner is that in order for the building to be "added" to would require separate buildings on the same lot with fire separations per T602 & T601, and separate structural walls for the building/addition.

Thoughts?

POP

 

[Frank]

Frank, Addition to the building will decrease it's open perimeter yes BUT it cannot be a compliance issue. 3403.1 regards the height and area of the existing building not being permitted to increase not open perimeter. IF that was the case no building would be able to increase. Addition of a fire wall isn't an option as well in my opinion. What we have here isn't an issue of maintaining fire areas to a given size in order to not sprinkler but rather a already non-sprinklered school that wishes to be larger. My "opinion" whatever it's worth as plans examiner is that in order for the building to be "added" to would require separate buildings on the same lot with fire separations per T602 & T601, and separate structural walls for the building/addition.

Thoughts?

POP

"3403.1 General.

Additions to any building or structure shall comply with the requirements of this code for new construction. Alterations to the existing building or structure shall be made to ensure that the existing building or structure together with the addition are no less conforming with the provisions of this code than the existing building or structure was prior to the addition. An existing building together with its additions shall comply with the height and area provisions of Chapter 5. "

Reducing the open perimeter of an existing building that does not conform with height and area requirements makes the existing building less conforming with the provisions of this code than the existing building was before.

Some buildings can increase and some cannot without ofsetting provisions of an added firewall or sprinklers to make it no more nonconforming.

Example I have a building designed to max out area with all increases sprinkler and open perimeter, I cannot just put up a fire wall and extend one side as this would make the existing building out of compliance with the current height and area limits.

Example of a non sprinklered school here that was about 450% of the allowable area after increases by current code. Wanted an addition. Upgraded a wall to a firewall back in the building so got areas of about 200% and 270% of current allowable area after increases. Totals exceed 100% due to each new building having less open perimeter than the one building before. Additional firewall seperation at the addition. The addition and a bit of the existing building complies with height and area, and the existing building has a lower degree of noncompliance.

In another case the existing building was sprinklered reducing the degree of noncompliance.

 

[mtlogcabin]

IEBC

1002.2 Area limitations.

No addition shall increase the area of an existing building beyond that permitted under the applicable provisions of Chapter 5 of the International Building Code for new buildings unless fire separation as required by the International Building Code is provided.

IBC

503.1 General.

The building height and area shall not exceed the limits specified in Table 503 based on the type of construction as determined by Section 602 and the occupancies as determined by Section 302 except as modified hereafter. Each portion of a building separated by one or more fire walls complying with Section 706 shall be considered to be a separate building.

Your building is already over the allotted area. Any additions will make it worse. Sprinklering the building or providing fire walls to divide the existing building and the addition are your only options that I see.