A wood construction method where each floor is built as a platform before the walls for the next level are constructed on top.

Platform framing is a wood construction method where each floor is built as a complete platform before the walls for the next level are constructed on top of it, creating a systematic approach to multi-story building construction that has become the standard method for residential and light commercial wood frame construction. This technique involves constructing the floor system first, including joists, subfloor, and rim boards, then building the walls on this platform and raising them into position before proceeding to the next floor level. Platform framing offers significant advantages in construction efficiency, safety, and material usage compared to older methods like balloon framing, making it the predominant construction method for wood-framed buildings throughout North America.

Platform framing is used in various construction applications including single-family residential construction where it provides an efficient method for building homes of various sizes and configurations, multi-family housing projects such as townhouses, condominiums, and apartment buildings up to several stories in height, light commercial construction including retail buildings, offices, and mixed-use developments, addition and renovation projects where new construction must integrate with existing structures, and modular or prefabricated construction where standardized platform sections can be built off-site and assembled on location. The method’s versatility makes it suitable for a wide range of building types and architectural styles.

The construction sequence and methodology of platform framing follows a systematic approach beginning with foundation preparation and installation of sill plates or mudsills that provide the base for the first floor platform, floor framing including installation of floor joists, rim boards, and subflooring to create a solid working platform, wall framing where walls are typically built flat on the platform and then raised into position, followed by installation of the top plate system that caps the walls and provides bearing for the next floor level. This sequence is repeated for each additional story, with each floor serving as a platform for constructing the level above.

Fun Fact: Platform framing became popular in the 1940s and 1950s when the availability of power tools and standardized lumber sizes made it more efficient than traditional balloon framing, revolutionizing residential construction and enabling the post-war housing boom.

• Framing
• Framing Square
• Ladder Framing