I think they meant what they wrote, they just forgot some punctuation.

'timber framing (for buildings) under about 6 feet'

I assume they meant “five-over-one”, five floors of stick built (framed with dimensional lumber, not timber) apartments on top of a concrete and steel first floor.

Timber framing is something else entirely, you can construct buildings taller than six stories with engineered wood products.

> The mid-rise buildings are normally constructed with four or five wood-frame stories above a concrete podium, usually for retail or resident amenity space.

https://en.wikipedia.org/wiki/5-over-1