Wash. Admin. Code § 51-50-0504

Current through Register Vol. 25-01, January 1, 2025

Section 51-50-0504 - Section 504-Building height and number of stories

Table 504.3

Allowable Building Height in Feet Above Grade Plane^a

Occupancy Classification	Type of Construction
	See Footnotes	Type I		Type II		Type III		Type IV				Type V
	See Footnotes	A	B	A	B	A	B	A	B	C	HT	A	B
A, B, E, F, M, S, U	NS^b	UL	160	65	55	65	55	65	65	65	65	50	40
A, B, E, F, M, S, U	S	UL	180	85	75	85	75	270	180	85	85	70	60
H-1, H-2, H-3, H-5	NS^c,d	UL	160	65	55	65	55	120	90	65	65	50	40
H-1, H-2, H-3, H-5	S
H-4	NS^c,d	UL	160	65	55	65	55	65	65	65	65	50	40
H-4	S	UL	180	85	75	85	75	140	100	85	85	70	60
I-1 Condition 1, I-3	NS^d,e	UL	160	65	55	65	55	65	65	65	65	50	40
I-1 Condition 1, I-3	S	UL	180	85	75	85	75	180	120	85	85	70	60
I-1 Condition 2, I-2	NS^d,e,f	UL	160	65	55	65	55	65	65	65	65	50	40
I-1 Condition 2, I-2	Sⁱ	UL	180	85
I-4	NS^d,g	UL	160	65	55	65	55	65	65	65	65	50	40
I-4	S	UL	180	85	75	85	75	180	120	85	85	70	60
R^h	NS^d	UL	160	65	55	65	55	65	65	65	65	50	40
	S13D	60	60	60	60	60	60	60	60	60	60	50	40
	S13R	60	60	60	60	60	60	60	60	60	60	60	60
	S	UL	180	85	75	85	75	270	180	85	85	70	60

For SI: 1 foot = 304.8 mm.

UL = Unlimited; NS = Buildings not equipped throughout with an automatic sprinkler system; S = Buildings equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.1; S13R = Buildings equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.2; S13D = Buildings equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.3.

^a See Chapters 4 and 5 for specific exceptions to the allowable height in this chapter.

^b See Section 903.2 for the minimum thresholds for protection by an automatic sprinkler system for specific occupancies.

^c New Group H occupancies are required to be protected by an automatic sprinkler system in accordance with Section 903.2.5.

^d The NS value is only for use in evaluation of existing building height in accordance with the International Existing Building Code.

^e New Group I-1 and I-3 occupancies are required to be protected by an automatic sprinkler system in accordance with Section 903.2.6. For new Group I-1 occupancies Condition 1, see Exception 1 of Section 903.2.6.

^f New and existing Group I-2 occupancies are required to be protected by an automatic sprinkler system in accordance with Section 903.2.6 and Section 1103.5 of the International Fire Code.

^g For new Group I-4 occupancies, see Exceptions 2 and 3 of Section 903.2.6.

^h New Group R occupancies are required to be protected by an automatic sprinkler system in accordance with Section 903.2.8.

ⁱ I-1, Condition 2 Assisted living facilities licensed in accordance with chapter 388-78A WAC and residential treatment facilities as licensed by Washington state under chapter 246-337 WAC shall be permitted to use the allowable height above grade plane for Group R-2 occupancies.

Table 504.4

Allowable Number of Stories Above Grade Plane^a,b

Occupancy Classification	Type of Construction
	See Footnotes	Type I		Type II		Type III		Type IV				Type V
	See Footnotes	A	B	A	B	A	B	A	B	C	HT	A	B
A-1	NS	UL	5	3	2	3	2	3	3	3	3	2	1
A-1	S	UL	6	4	3	4	3	9	6	4	4	3	2
A-2	NS	UL	11	3	2	3	2	3	3	3	3	2	1
A-2	S	UL	12	4	3	4	3	18	12	6	4	3	2
A-3	NS	UL	11	3	2	3	2	3	3	3	3	2	1
A-3	S	UL	12	4	3	4	3	18	12	6	4	3	2
A-4	NS	UL	11	3	2	3	2	3	3	3	3	2	1
A-4	S	UL	12	4	3	4	3	18	12	6	4	3	2
A-5	NS	UL	UL	UL	UL	UL	UL	1	1	1	UL	UL	UL
A-5	S	UL	UL	UL	UL	UL	UL	UL	UL	UL	UL	UL	UL
B	NS	UL	11	5	3	5	3	5	5	5	5	3	2
B	S	UL	12	6	4	6	4	18	12	9	6	4	3
E	NS	UL	5	3	2	3	2	3	3	3	3	1	1
E	S	UL	6	4	3	4	3	9	6	4	4	2	2
F-1	NS	UL	11	4	2	3	2	3	3	3	4	2	1
F-1	S	UL	12	5	3	4	3	10	7	5	5	3	2
F-2	NS	UL	11	5	3	4	3	5	5	5	5	3	2
F-2	S	UL	12	6	4	5	4	12	8	6	6	4	3
H-1	NS^c,d	1	1	1	1	1	1	NP	NP	NP	1	1	NP
H-1	S	1	1	1	1	1	1	1	1	1	1	1	NP
H-2	NS^c,d	UL	3	2	1	2	1	1	1	1	2	1	1
H-2	S	UL	3	2	1	2	1	2	2	2	2	1	1
H-3	NS^c,d	UL	6	4	2	4	2	3	3	3	4	2	1
H-3	S	UL	6	4	2	4	2	4	4	4	4	2	1
H-4	NS^c,d	UL	7	5	3	5	3	5	5	5	5	3	2
H-4	S	UL	8	6	4	6	4	8	7	6	6	4	3
H-5	NS^c,d	4	4	3	3	3	3	2	2	2	3	3	2
H-5	S	4	4	3	3	3	3	3	3	3	3	3	2
I-1 Condition 1	NS^d,e	UL	9	4	3	4	3	4	4	4	4	3	2
I-1 Condition 1	S	UL	10	5	4	5	4	10	7	5	5	4	3
I-1 Condition 2	NS^d,e	UL	9	4	3	4	3	3	3	3	4	3	2
I-1 Condition 2	Sⁱ	UL	10	5	3	4	3	10	6	4	4	3	2
I-2	NS^d,f	UL	4	2	1	1	NP	NP	NP	NP	1	1	NP
I-2	S	UL	5	3	1	1	NP	7	5	1	1	1	NP
I-3	NS^d,e	UL	4	2	1	2	1	2	2	2	2	2	1
I-3	S	UL	5	3	2	3	2	7	5	3	3	3	2
I-4	NS^d,g	UL	5	3	2	3	2	3	3	3	3	1	1
I-4	S	UL	6	4	3	4	3	9	6	4	4	2	2
M	NS	UL	11	4	2	4	2	4	4	4	4	3	1
M	S	UL	12	5	3	5	3	12	8	6	5	4	2
R-1^h	NS^d	UL	11	4	4	4	4	4	4	4	4	3	2
	S13R	4	4	4	4	4	4	4	4	4	4	4	3
	S	UL	12	5	5	5	5	18	12	8	5	4	3
R-2^h	NS^d	UL	11	4	4	4	4	4	4	4	4	3	2
	S13R	4	4	4	4	4	4	4	4	4	4	4	3
	S	UL	12	5	5	5	5	18	12	8	5	4	3
R-3^h	NS^d	UL	11	4	4	4	4	4	4	4	4	3	3
	S13D	4	4									3	3
	S13R	4	4									4	4
	S	UL	12	5	5	5	5	18	12	5	5	4	4
R-4^h	NS^d	UL	11	4	4	4	4	4	4	4	4	3	2
	S13D	4	4									3	2
	S13R	4	4									4	3
	S	UL	12	5	5	5	5	18	12	5	5	4	3
S-1	NS	UL	11	4	2	3	2	4	4	4	4	3	1
S-1	S	UL	12	5	4	4	4	10	7	5	5	4	2
S-2	NS	UL	11	5	3	4	3	4	4	4	5	4	2
S-2	S	UL	12	6	4	5	4	12	8	5	6	5	3
U	NS	UL	5	4	2	3	2	4	4	4	4	2	1
U	S	UL	6	5	3	4	3	9	6	5	5	3	2

UL = Unlimited; NP = Not permitted; NS = Buildings not equipped throughout with an automatic sprinkler system; S = Buildings equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.1; S13R = Buildings equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.2; S13D = Buildings equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.3.

^a See Chapters 4 and 5 for specific exceptions to the allowable height in this chapter.

^b See Section 903.2 for the minimum thresholds for protection by an automatic sprinkler system for specific occupancies.

^c New Group H occupancies are required to be protected by an automatic sprinkler system in accordance with Section 903.2.5.

^d The NS value is only for use in evaluation of existing building height in accordance with the International Existing Building Code.

^f New and existing Group I-2 occupancies are required to be protected by an automatic sprinkler system in accordance with Section 903.2.6 and Section 1103.5 of the International Fire Code.

^g For new Group I-4 occupancies, see Exceptions 2 and 3 of Section 903.2.6.

^h New Group R occupancies are required to be protected by an automatic sprinkler system in accordance with Section 903.2.8.

ⁱ Group I-1, Condition 2 Assisted living facilities licensed in accordance with chapter 388-78A WAC and residential treatment facilities as licensed by Washington state under chapter 246-337 WAC shall be permitted to use the allowable number of stories for Group R-2 occupancies.

504.4.1Stair enclosure pressurization increase. For Group R-1, R-2, and I-1 Condition 2 Assisted living facilities licensed under chapter 388-78A WAC and residential treatment facilities as licensed by Washington state under chapter 246-337 WAC located in buildings of Type VA construction equipped throughout with an approved automatic sprinkler system in accordance with Section 903.3.1.1, the maximum number of stories permitted in Section 504.4 may be increased by one provided the interior exit stairways and ramps are pressurized in accordance with Sections 909.6.3 and 909.20. Legally required standby power shall be provided in accordance with Sections 909.11 and 2702.17 for buildings constructed in compliance with this section and be connected to stairway shaft pressurization equipment, elevators and lifts used for accessible means of egress (if provided), elevator hoistway pressurization equipment (if provided) and other life safety equipment as determined by the authority having jurisdiction. For the purposes of this section, legally required standby power shall comply with 2020 NEC Section 701.12, options (C), (D), (E), (F), (H) or (J) or subsequent revised section number(s).

Wash. Admin. Code § 51-50-0504

Amended by WSR 16-03-064, Filed 1/19/2016, effective 7/1/2016

Amended by WSR 19-02-038, Filed 12/26/2018, effective 7/1/2019

Amended by WSR 20-01-090, Filed 12/12/2019, effective 7/1/2020

Amended by WSR 20-21-021, Filed 10/9/2020, effective 11/9/2020

Amended by WSR 21-06-035, Filed 2/23/2021, effective 3/26/2021

Amended by WSR 22-13-094, Filed 6/14/2022, effective 7/1/2023

Amended by WSR 23-23-102, Filed 11/15/2023, effective 3/16/2024

Statutory Authority: RCW 19.27.031 and chapters 19.27 and 34.05 RCW. 13-04-067, § 51-50-0504, filed 2/1/13, effective 7/1/13. Statutory Authority: Chapter 19.27 RCW. 10-24-059, § 51-50-0504, filed 11/29/10, effective 7/1/11.