What are the differences between balloon framing and platform framing? What are the advantages and disadvantages of each? What has platform framing become the method of choice?

Floor platform framing – each floor is built then walls then floor until reaching the roof where there are variations. Advantages – uses short and easily handled lengths. Consists of thicker layer of wood whose grains run horizontally. This leads to large amount of vertical shrinkage in the frame which leads to the distress in the exterior and interior finish surfaces.

Why is little added fire stopping required in platform framing?       

The vertical hollow spaces are automatically fire stopped at each floor.

Why is a steel beam or glue-laminated wood beam preferred to a solid wood beam at the foundation level?

Solid wood is recommended in cold regions. Wood underground may shrink and tilt the floor a steel beam will not. Glue laminated wood is stable.

How is a platform frame building braced against wind and earthquake forces?

braced against wind and earthquake forces. Boards applied diagonally at the corner create a rigid form. Sheathed wall acts as a shear wall which resists the lateral forces.

Light framing of wood is highly combustible. In what different ways does a typical building code take this fact into account?

Because of their vulnerability to fire, the comprehensive life-safety requirements of modern building codes ensures that they are safe places built of(firewall) brick/masonry