Open to Below:Open to Below:Open to Below: A Discussion of Allowed Floor Openings

Open to Below: A Discussion of Allowed Floor Openings

Kevin S. Hastings, P.E., LEED APJay A. Ierardi, Ph.D., P.E., LEED AP

Kevin S. Hastings, P.E., LEED APJay A. Ierardi, Ph.D., P.E., LEED AP

R W S lli an EngineeringR W S lli an EngineeringR.W. Sullivan EngineeringR.W. Sullivan Engineering

(617) 523(617) 523--8227, Fax (617) 5238227, Fax (617) 523--80168016

http://www.rwsullivan.comhttp://www.rwsullivan.com

WelcomeWelcomeWelcomeWelcome• The Boston Society of Architects/AIA is a Registered

Provider with The American Institute of Architects Continuing• The Boston Society of Architects/AIA is a Registered

Provider with The American Institute of Architects ContinuingProvider with The American Institute of Architects Continuing Education Systems. Credit earned on completion of this program will be reported to CES Records for AIA members. Certificates of Completion for non-AIA members are available on request

Provider with The American Institute of Architects Continuing Education Systems. Credit earned on completion of this program will be reported to CES Records for AIA members. Certificates of Completion for non-AIA members are available on requeston request.

This program is registered with the AIA/CES for continuing professional education. As such, it does not include content that may be deemed or construed to be an approval or

on request.

This program is registered with the AIA/CES for continuing professional education. As such, it does not include content that may be deemed or construed to be an approval orthat may be deemed or construed to be an approval or endorsement by the AIA of any material of construction or any method or manner of handling, using, distributing, or dealing in any material or product. Questions related to specific materials methods and services will be addressed at the

that may be deemed or construed to be an approval or endorsement by the AIA of any material of construction or any method or manner of handling, using, distributing, or dealing in any material or product. Questions related to specific materials methods and services will be addressed at thematerials, methods, and services will be addressed at the conclusion of this presentation.materials, methods, and services will be addressed at the conclusion of this presentation.

Learning ObjectivesLearning ObjectivesLearning ObjectivesLearning Objectives• Every floor opening is not an atrium! • Every floor opening is not an atrium! y p g

• 2009 IBC and NFPA 101 provide options for other

y p g

• 2009 IBC and NFPA 101 provide options for other allowed floor openings.

A hit t l l ti t d li i t

allowed floor openings.

A hit t l l ti t d li i t• Architectural solutions to reduce or eliminate mechanical smoke exhaust in atriums.

• Architectural solutions to reduce or eliminate mechanical smoke exhaust in atriums.

• Basic understanding of performance-based approaches to floor openings and smoke control.

• Basic understanding of performance-based approaches to floor openings and smoke control.

R W Sullivan Engineering (RWS) wasR.W. Sullivan Engineering (RWS) was established in 1945 and currently has 

90 employees90 employees.

RWS is a full service engineering firm offering integrated services in the 

following disciplines:

ElectricalElectricalHVACHVAC Plumbing Fire Protection Code

AgendaFl O i P t ti

AgendaFl O i P t tiFloor Opening ProtectionFloor Opening Protection

• CodesInternational Building Code 2003 Edition (780 CMR 7th Edition)

• CodesInternational Building Code 2003 Edition (780 CMR 7th Edition)– International Building Code, 2003 Edition (780 CMR 7th Edition)

– International Building Code, 2009 Edition (780 CMR 8th Edition)– NFPA 101: Life Safety Code

NFPA 92B S k M t S t

– International Building Code, 2003 Edition (780 CMR 7th Edition)– International Building Code, 2009 Edition (780 CMR 8th Edition)– NFPA 101: Life Safety Code

NFPA 92B S k M t S t– NFPA 92B: Smoke Management Systems

• Types of Floor OpeningsG l

– NFPA 92B: Smoke Management Systems

• Types of Floor OpeningsG l– General

– 2-Story Floor Openings– 3+ Story Floor Openings

– General– 2-Story Floor Openings– 3+ Story Floor Openings– Atriums– Other Permitted Unenclosed Openings

• Performance Based Approaches

– Atriums– Other Permitted Unenclosed Openings

• Performance Based Approaches• Performance Based Approaches• Performance Based Approaches

General Floor OpeningsGeneral Floor Openingsp gShaft Enclosures

p gShaft Enclosures

• IBC and NFPA 101 require floor openings comply with one of the following:

• IBC and NFPA 101 require floor openings comply with one of the following:following:– 1 hour rated shaft when

connecting 2 or 3 floors.– 2 hour rated shaft when

following:– 1 hour rated shaft when

connecting 2 or 3 floors.– 2 hour rated shaft when

connecting more than 3 floors.– Meet an exception for an

allowed floor opening.

connecting more than 3 floors.– Meet an exception for an

allowed floor opening.

2-Story Floor Openings2-Story Floor Openings2 Story Floor Openings2 Story Floor Openings

2-Story Floor Openings2-Story Floor Openings2 Story Floor Openings2 Story Floor Openings

Code Code Section Prohibited Uses

Used for Egress Required Separation

2009 IBC 708.2 E ti 7

Use Group &

PermittedCorridors in Use Group I & R

C009 C Exception 7 I-2 & I-3

e ttedAll Unsprinklered Corridors

NFPA 1018.6.8.1 None Not

Permitted One of the Floors

8 6 8 2 Unsprinklered Not All Corridors8.6.8.2 pAssembly Permitted All Corridors

2-Story Open Exit Stairs 2-Story Open Exit Stairs y p2009 IBC Section 1016.1 (Not Allowed by NFPA 101)

y p2009 IBC Section 1016.1 (Not Allowed by NFPA 101)

• Exception 3 allows for 50% of the exit stairs • Exception 3 allows for 50% of the exit stairs between any 2 stories to be unenclosed and used as an exit stair. This stair however cannot be open to more than the two connected stories

between any 2 stories to be unenclosed and used as an exit stair. This stair however cannot be open to more than the two connected storiesopen to more than the two connected stories.open to more than the two connected stories.

1 Hour Wall1 Hour Wall1 Hour Wall1 Hour Wall

2-Story Open Exit Stairs 2-Story Open Exit Stairs y p2009 IBC Section 1016.1 (Not Allowed by NFPA 101)

y p2009 IBC Section 1016.1 (Not Allowed by NFPA 101)

• Exception 4 allows for all exit stairs between the • Exception 4 allows for all exit stairs between the pfirst 2 stories to be unenclosed and used as exit stairs in a fully sprinklered building. The connected floors must have 2 exits and are not

pfirst 2 stories to be unenclosed and used as exit stairs in a fully sprinklered building. The connected floors must have 2 exits and are notconnected floors must have 2 exits and are not permitted to be open to any other floors.connected floors must have 2 exits and are not permitted to be open to any other floors.

Multiple 2-Story Floor OpeningsMultiple 2-Story Floor OpeningsMultiple 2 Story Floor OpeningsMultiple 2 Story Floor Openings

4th floor

3rd floor

2nd floor

Rated separationRated separationRated separationRated separation

Boundaries of floor Boundaries of floor openingsopeningsBoundaries of floor Boundaries of floor openingsopenings

1st floor

openingsopeningsopeningsopenings

2-Story Floor Openings2-Story Floor Openingsy p gAlternative Approach

y p gAlternative Approach

Sprinkler Protected Sprinkler Protected Gl i R tiGl i R ti

3rd floorGlazing or Rating Glazing or Rating Equivalent to FloorEquivalent to Floor

2nd floor

1st floor

•• Alternative design requires approval from the Authority Having Alternative design requires approval from the Authority Having Jurisdiction or a variance.Jurisdiction or a variance.

•• Provides smoke reservoir that performs better than a Provides smoke reservoir that performs better than a continuous floor assembly.continuous floor assembly.

Alternative 2-Story ExampleAlternative 2-Story ExampleAlternative 2 Story ExampleAlternative 2 Story Example• Laboratory Building• Laboratory Building

– 3-story floor open (outlined in red)– No smoke control provided– 3-story floor open (outlined in red)– No smoke control provided

3+ Story Floor Openings3+ Story Floor Openings3+ Story Floor Openings3+ Story Floor Openings

3+ Story Floor Openings3+ Story Floor Openings3+ Story Floor Openings3+ Story Floor Openings

SizeCode Code Section Restrictions Size Limits Required Separation

NFPA 101 8.6.8.6•Escalators only•No more than 4 stories in Use Groups B & M w/ sprinkler option

Twice the Escalator

Area

Draft curtains w/ closely spaced sprinklers ORShutter at every floor Groups B & M w/ sprinkler option Area

opening

2009 IBC708.2 Exception 2“Escalator /Open

Stair”

•Unsprinklered Buildings•4 Floors Max in Use Groups other than B & M

Twice the Stair Area

Draft Curtains w/ Closely Spaces

Sprinklers

U i kl d Ed ti lNFPA 101

IEBC

8.6.6“Mini-Atrium”

703.2.1

•Unsprinklered Educational•All Healthcare•Unsprinklered Apartments•Lowest or Next to Lowest Level must be a Street Floor

None

Smoke BarriersAdjacent spaces have

access to an exit without entering the

communicating space.

•No more than 3 Floors

Escalator / O St i P t ti

Escalator / O St i P t tiOpen Stair Protection

2009 IBC 708.2 Exc. 2; NFPA 101 8.6.8.6 (Escalator Only)Open Stair Protection

2009 IBC 708.2 Exc. 2; NFPA 101 8.6.8.6 (Escalator Only)

• Openings protected with a draft curtain and closely

d i kl Th

• Openings protected with a draft curtain and closely

d i kl Thspaced sprinklers. The opening area is limited to twice the horizontal

spaced sprinklers. The opening area is limited to twice the horizontal projected area of the escalator. Also, 2009 IBC limit openings to not more

projected area of the escalator. Also, 2009 IBC limit openings to not morelimit openings to not more than 4 stories in Use Groups other than B & M.

limit openings to not more than 4 stories in Use Groups other than B & M.

Escalator Protection f O St i

Escalator Protection f O St ifor Open Stairs

NFPA 101for Open Stairs

NFPA 101

• The “Manual Escalator”• The “Manual Escalator”

• Same hazard as an escalator, however only 2009 IBC permit the use of the previously described options for protecting a standard open stair.

• Same hazard as an escalator, however only 2009 IBC permit the use of the previously described options for protecting a standard open stair.options for protecting a standard open stair.

• Approval from the Authority Having Jurisdiction or

options for protecting a standard open stair.

• Approval from the Authority Having Jurisdiction or a variance is required for states adopting NFPA 101.a variance is required for states adopting NFPA 101.

Mini-Atrium: ConfigurationNFPA 101 8 6 6 & IEBC 703 2 1 E ti 3

Mini-Atrium: ConfigurationNFPA 101 8 6 6 & IEBC 703 2 1 E ti 3NFPA 101 8.6.6 & IEBC 703.2.1 Exception 3NFPA 101 8.6.6 & IEBC 703.2.1 Exception 3

• Connects no more than 3 stories• Connects no more than 3 stories(Not Limited by IEBC)

• Lowest or next-to-lowest floor is street level

(Not Limited by IEBC)

• Lowest or next-to-lowest floor is street level

• Open and unobstructed communicating space• Open and unobstructed communicating space

Mini-Atrium: Fire ProtectionNFPA 101 8 6 6 & IEBC 703 2 1 E ti 3

Mini-Atrium: Fire ProtectionNFPA 101 8 6 6 & IEBC 703 2 1 E ti 3NFPA 101 8.6.6 & IEBC 703.2.1 Exception 3NFPA 101 8.6.6 & IEBC 703.2.1 Exception 3

• NFPA Fire Separation Options– 1 hr fire barrier

• NFPA Fire Separation Options– 1 hr fire barrier– Smoke barrier in a fully sprinklered building– No separation required for detention/correction housing

C S

– Smoke barrier in a fully sprinklered building– No separation required for detention/correction housing

C S• IEBC Fire Separation– Smoke Barrier

• IEBC Fire Separation– Smoke Barrier

Mini-Atrium: EgressNFPA 101 8 6 6

Mini-Atrium: EgressNFPA 101 8 6 6NFPA 101 8.6.6NFPA 101 8.6.6

• Considered a single floor area for egress capacity

• Considered a single floor area for egress capacityfor egress capacity

• Occupants within the mini-atrium t t l t it ith t h i t

for egress capacity

• Occupants within the mini-atrium t t l t it ith t h i t– access to at least one exit without having to

traverse another story within the mini-atrium space

• Occupants outside the mini atrium

– access to at least one exit without having to traverse another story within the mini-atrium space

• Occupants outside the mini atrium• Occupants outside the mini-atrium – access to at least one exit without having to enter the

mini-atrium space

• Occupants outside the mini-atrium – access to at least one exit without having to enter the

mini-atrium space

Other Permitted Other Permitted Unenclosed Openings

2009 IBC Section 708.2Unenclosed Openings

2009 IBC Section 708.2

• 4 story opening within a dwelling unit (Exception 1)

• Mezzanines (Exception 9)

• 4 story opening within a dwelling unit (Exception 1)

• Mezzanines (Exception 9)

• Ramps in parking structures (Exception 8)

• Elevator hoistways serving only parking structures (Exception

• Ramps in parking structures (Exception 8)

• Elevator hoistways serving only parking structures (Exception y g y p g ( p14)

• Use Group I-3 in accordance with 780 CMR 408.5 (Exception 13)

y g y p g ( p14)

• Use Group I-3 in accordance with 780 CMR 408.5 (Exception 13)13)13)

AtriumsAtriumsAtriumsAtriums

AtriumsAtriums2009 IBC 404, NFPA 101 8.6.72009 IBC 404, NFPA 101 8.6.7

GG• General requirements

– Sprinkler Protection: Atriums must be protected with i kl (2009 IBC 404 3 NFPA 101 8 6 7(4))

• General requirements

– Sprinkler Protection: Atriums must be protected with i kl (2009 IBC 404 3 NFPA 101 8 6 7(4))sprinklers (2009 IBC 404.3, NFPA 101 8.6.7(4)).

– Travel Distance: Other than the lowest floor, the egress travel distance through an atrium is limited to

sprinklers (2009 IBC 404.3, NFPA 101 8.6.7(4)).

– Travel Distance: Other than the lowest floor, the egress travel distance through an atrium is limited toegress travel distance through an atrium is limited to 200 ft (2009 IBC 404.9).

– Exit Discharge: Permitted within the atrium (NFPA

egress travel distance through an atrium is limited to 200 ft (2009 IBC 404.9).

– Exit Discharge: Permitted within the atrium (NFPA g (101 8.6.7(2)).

g (101 8.6.7(2)).

Enclosure of AtriumEnclosure of Atrium2009 IBC 404.6, NFPA 101 8.6.7(1)2009 IBC 404.6, NFPA 101 8.6.7(1)

• Atriums are required to be separated from adjacent spaces by 1 hour rated construction except:

• Atriums are required to be separated from adjacent spaces by 1 hour rated construction except:

– 3 stories are permitted to be open to the atrium if the volume calculated for the design of the smoke control system includes the volume of the spaces not separated

– 3 stories are permitted to be open to the atrium if the volume calculated for the design of the smoke control system includes the volume of the spaces not separated y p pfrom the atrium. (No limit in NFPA 101)

– Sprinkler protected glass

y p pfrom the atrium. (No limit in NFPA 101)

– Sprinkler protected glass

Sprinkler Protected GlassSprinkler Protected GlassSprinkler Protected GlassSprinkler Protected Glass

Atrium Smoke ControlAtrium Smoke Control2009 IBC 404.52009 IBC 404.5

• Smoke control is required in all atriums that connect more• Smoke control is required in all atriums that connect moreSmoke control is required in all atriums that connect more than 2 stories (“connect” = opening in floor slab).Smoke control is required in all atriums that connect more than 2 stories (“connect” = opening in floor slab).

Smoke Control Design CriteriaSmoke Control Design CriteriaSmoke Control Design CriteriaSmoke Control Design Criteria

Component780 CMR

6th Edition2003 IBC

NFPA 101 / 92B2009 IBC

Interface height above highest walking surface

open to the atrium6 ft. 10 ft. 6 ft.

5000 BTU/s Determined byDesign fire size 2000 BTU/s 5000 BTU/s minimum

Determined by Analysis

Fire scenarios AxisymmetricAxisymmetric, Balcony Spill,

Window

Determined by AnalysisWindow

Time 20 min 20 min 1.5 times egress

Example AtriumExample Atrium

Example Exhaust RatesExample Exhaust RatesExample Exhaust RatesExample Exhaust Rates

• Example 5-story atrium• Example 5-story atrium

Code Exhaust Requirement (cfm)

Free Area for make-up air @ 200 ft/min (ft2)

Example 5 story atriumExample 5 story atrium

Requirement (cfm) air @ 200 ft/min (ft )6th Edition (2,000 Btu/s) 195,930 980

2003 IBC (5,000 Btu/s) 664,430 3,320

2009 IBC (2,000 Btu/s) 479,655 2,400

2009 IBC w/modeling 207,830 600*

* Fire modeling may show make-up air > 200 ft/min is acceptable* Fire modeling may show make-up air > 200 ft/min is acceptable

• Fire modeling permitted with a third party review (MA only)• Fire modeling permitted with a third party review (MA only)

Fire modeling may show make up air 200 ft/min is acceptable Fire modeling may show make up air 200 ft/min is acceptable

• Variances for fire modeling are no longer required• Variances for fire modeling are no longer required

Exhaust RatesExhaust RatesExhaust RatesExhaust Rates

Open FloorsExhaust Requirement (cfm)

780 CMR 6th

Edition IBCEdition1 thru 5 195,927 664,4301 thru 4 138,313 487,5931 thru 3 89,269 337,6031 thru 2 49,631 187,613

1 8 604 35 9481 8,604 35,948

Performance Based A h

Performance Based A hApproachesApproaches

• Due to the large exhaust rates under IBC alternative designs will likely become more common.

• Due to the large exhaust rates under IBC alternative designs will likely become more common.

– 780 CMR, 7th Edition permits alternative designs for smoke control systems (780 CMR 909.20.4).

d

– 780 CMR, 7th Edition permits alternative designs for smoke control systems (780 CMR 909.20.4).

d– A 3rd party review and variance is currently required for all alternative designs in Massachusetts (780 CMR 901.7.2.1).

– 2009 IBC references NFPA 92B which allows CFD modeling

– A 3rd party review and variance is currently required for all alternative designs in Massachusetts (780 CMR 901.7.2.1).

– 2009 IBC references NFPA 92B which allows CFD modeling2009 IBC references NFPA 92B which allows CFD modeling2009 IBC references NFPA 92B which allows CFD modeling

Alternative Design ExamplesAlternative Design ExamplesAlternative Design ExamplesAlternative Design Examples

• Shutters / Curtains– Used to enclose the

upper stories of an atrium

• Shutters / Curtains– Used to enclose the

upper stories of an atriumatrium.

– Activated by building fire alarm system.

• Egress

atrium.– Activated by building fire

alarm system.• EgressEgress

– Access to required exits outside the atrium boundary

Fi M d li

Egress– Access to required exits

outside the atrium boundary

Fi M d li• Fire Modeling– Used to estimate actual

smoke production and spread.

• Fire Modeling– Used to estimate actual

smoke production and spread.p

• Deluge Sprinkler System– Used to limit the fire size.

p• Deluge Sprinkler System

– Used to limit the fire size.

Atrium EgressAtrium Egress•• Access to required exits without entering the atrium and allowing Access to required exits without entering the atrium and allowing

the smoke to lower down.the smoke to lower down.

Atrium Fire ModelingAtrium Fire Modelinggg

Atrium Fire ModelingAtrium Fire ModelingAtrium Fire ModelingAtrium Fire Modeling•• PlugholingPlugholing

–– Relatively shallow smoke layer depth and a high exhaust rate Relatively shallow smoke layer depth and a high exhaust rate can lead to the entrainment of cold air from the clear layer.can lead to the entrainment of cold air from the clear layer.

Alternative Protection ExampleAlternative Protection Examplepp• Life Sciences Laboratory Building

– 2-story floor open (shown in red)• Life Sciences Laboratory Building

– 2-story floor open (shown in red)– Designed as an atrium per NFPA 101– No smoke control provided based on analysis– Designed as an atrium per NFPA 101– No smoke control provided based on analysis

Alternative Protection ExampleAlternative Protection Examplepp

Visibility and Smoke Movement: Floor Visibility and Smoke Movement: Floor Opening in a University BuildingOpening in a University BuildingOpening in a University BuildingOpening in a University Building

154

ft

208 ft208 ft

Thank you.Thank you.This concludes The American Institute of Architects This concludes The American Institute of Architects

Continuing Education Systems program.Continuing Education Systems program.

QUESTIONS?QUESTIONS?Kevin S. Hastings, P.E., LEED APKevin S. Hastings, P.E., LEED AP

KSH@RWSullivan.comKSH@RWSullivan.com

617 337 9319617 337 9319

Jay A. Ierardi, Ph. D, P.E., LEED APJay A. Ierardi, Ph. D, P.E., LEED AP

JAI@RWSullivan.comJAI@RWSullivan.com

617 337 9321617 337 9321617.337.9319617.337.9319 617.337.9321617.337.9321