Which construction technique builds the frame of a structure one floor at a time, with firestop features?

Platform frame construction is indeed the correct answer because it involves building the structure's frame one floor at a time. This technique allows for each floor to be constructed independently and then becomes a platform for the next level. Each floor incorporates firestop features, which are critical for slowing the spread of fire and smoke between floors. These firestopping measures can consist of materials or assemblies that fill voids and openings in walls and floors to enhance safety and compliance with building codes.

The importance of the firestop features in platform frame construction cannot be overstated, as they play a crucial role in maintaining the integrity of fire barriers and ensuring the safety of occupants. This technique is widely used in residential housing and low-rise buildings, which contributes to its popularity in modern construction.

The other techniques mentioned do not involve the systematic construction of floors one at a time with integral fire stopping. Rafters are primarily used in roof construction, simple beams provide support but do not define a framing technique that includes fire stops or multiple floors, and pitched roofs refer to the sloped design of roofs rather than a framing method for constructing complete floor levels.