The phrase 5 over 1 refers wood-framed residential building 5 stories tall which is built over a concrete platform, which typically hosts a commercial space or a parking lot. 5 over 1 are a popular method for building apartments and adding density to urban areas, since they are cheaper and faster to build compared to steel-framed apartment buildings.
What are 5 over 1 buildings?
5 over 1 buildings are mid-rise residential structures built with a wood frame over a concrete platform, which makes them one of the cheapest options for building apartments or condos. Wood framing is less expensive than steel or metal framing, or using entirely concrete. The concrete base allows builders to construct a building that is one story taller than would normally be allowed for entirely wood-framed buildings under building code. This helps the building owner increase profitability by giving them the option to add commercial space on the first floor with apartments above.
5 over 1s are a popular building type in North American city centers and urban developments because of their growth and profitability potential, as they provide more apartments per acre than single family homes.
In the International Building Code, which is the building code in the United States, the concrete platform is a Type 1 building, and the wooden structure above is a Type 5 building. The building code allows for 5 stories of wood-framed buildings (a Type 5) building. The concrete platform (Type 1) acts as a base for those 5 stories, which allows builders to construct 1 extra level.
Benefits of a 5 over 1 building
The main benefit in a 5 over 1 building is the low construction cost. Wood framing allows you to build with speed and won’t be as expensive as a steel and concrete building. The concrete podium will give you a structure to maximize height while the wood will give you a cost-effective way to add up to 5 stories.
For the residents themselves, the buildings are affordable, often located in desirable urban communities, and offer amenities and functionality that many older buildings in those areas do not.