HomeKnowledgeNDS — National Design Specification for Wood Construction
📐 Standardstandardswood

NDS — National Design Specification for Wood Construction

Updated Mar 25, 2026
The governing standard for structural wood design in the US. Referenced by IBC Chapter 23.

NDS 2024 (AWC): design standard for sawn lumber, glulam, structural composite lumber, CLT, and connections. Design values: base values from NDS Supplement (species/grade), modified by adjustment factors. Key factors: CD (load duration: 0.9 permanent to 2.0 impact), CM (wet service: 0.8-1.0), Ct (temperature), Ci (incising), CL (beam stability), CF (size factor for sawn lumber), Cv (volume factor for glulam), CP (column stability). Allowable stress: F'b = Fb × CD × CM × Ct × CL × CF × Ci. Chapter 3 — Sawn lumber. Chapter 5 — Structural glulam. Chapter 7 — Structural composite lumber (LVL, PSL, LSL). Chapter 10 — Cross-laminated timber. Chapter 12 — Connections: dowel-type (bolts, lag screws, nails), lateral and withdrawal. Split ring, shear plates. NDS Supplement: design values for all commercial species/grades. Special Design Provisions for Wind and Seismic (SDPWS): shear walls, diaphragms.

TAGS
NDSwoodlumberglulamCLTdesign-standard
DETAILS
publisher
American Wood Council (AWC)
referenced by
["IBC Chapter 23"]
standard number
NDS 2024
RELATED KNOWLEDGE
📐 Standard
NFPA 13 — Standard for the Installation of Sprinkler Systems
The primary standard governing design and installation of automatic fire sprinkler systems. Referenced by IBC Chapter 9. Covers system types, pipe sizing, sprinkler spacing, water supply requirements.
📐 Standard
ASTM E119 — Standard Test Methods for Fire Tests of Building Construction and Materials
THE fire resistance test standard. Determines hourly fire ratings for walls, floors, roofs, columns, and beams. Referenced by IBC Table 601. Test uses standard time-temperature curve reaching 1700°F at 1 hour.
📐 Standard
ASCE 7 — Minimum Design Loads
Standard defining dead loads, live loads, snow loads, rain loads, wind loads, and seismic forces for building design. Referenced by IBC Chapter 16. Includes risk categories, importance factors, and load combinations.
📐 Standard
TMS 402 — Building Code Requirements for Masonry Structures
Design standard for masonry construction: allowable stress design, strength design, and empirical design of masonry.
📐 Standard
NFPA 72 — Fire Alarm and Signaling
National fire alarm and signaling code covering system design, installation, and testing of fire alarm, emergency communication, mass notification, and carbon monoxide detection systems.
📐 Standard
NFPA 101 — Life Safety Code
Comprehensive life safety code covering means of egress, fire protection features, building services, and operating features. Alternative to IBC egress provisions. Mandatory for CMS healthcare facilities.
← Back to Knowledge Garden