Are Steel Building Expandable

renegade steel building expandable main frame end wall illustration

Are Steel Buildings Expandable?

We often get asked "are steel buildings expandable".  The answer is that they can be designed for future expansion.  Of course that answer comes with a caveat.  There are pros and cons to making your steel building expandable.  First, lets take a look at the typical design of the end wall of a steel building.

Bearing Frame End Wall

Renegade steel building end wall sheeted

Steel Building End Wall

The typical and most common way to design and build an end wall on a steel building is utilizing what's called a bearing frame wall.  When you peel back the sheeting from the wall, you can see that there is no I-beam or main frame.  The wall is constructed using "Cee" channel, double "Cee" channel, or sometimes even hot rolled members to frame up and support the roof.  Don't worry, this is all done within spec of engineering to support your building adequately.  Since the load at the end wall is usually only half of what the clear span main frames have to support, this type of wall is more than sufficient and cost effective.
renegade steel buildings bearing frame end wall cut away

Steel Building End Wall Cut Away

So what if you are thinking you may want to expand the length of your building sometime in the future.  There are ways to do that by adding a main frame at the end wall to support the roof load.  This is called an expandable main frame.

Expandable Main Frame End Wall

renegade steel building expandable main frame end wall illustration

Expandable Main Frame End Wall with framing

When you design a building with an expandable main frame in the end wall, you still have the bearing frame wall as well.  This is to support the end wall sheeting while the main frame carries the load of the roof.  This main frame should be specified with a load width similar or wider than the main frames in the rest of the building.  In this illustration you can see the main frame sitting just inside the bearing frame wall.
Renegade steel buildings expandable main frame end wall open illustration

Expandable Main Frame End Wall

With this design, you can completely remove the wall when it comes time to expand your building.  The new addition should take into account that the main frame has been designed to carry the load of the roof.  Most manufacturers will want to take a look at the original building design before moving forward with an expansion like this to make sure all the engineering is proper and adequate.  If all is well, you will have an expansion that provides you with additional clear span floor space with no walls or obstacles.
renegade steel building expanded building illustration

Steel Building Expansion

Pros and cons of the expandable main frame


  • Easy to design up front for future expansion
  • The building has been engineered and steel provided for possible future use.


  • If you don't decide to expand in the future, you have paid more for additional steel that was not needed.
  • If building codes change, the current building may have to be brought up to existing code in order to do the expansion.
  • Care must be taken to maintain copies of drawings and engineering for future reference.

Are there any other options to expand?

There are several different ways to expand your building depending on what your needs are.  If you need more space and can deal with a wall between, you can order a building to abut your existing building designed with a non-expandable main frame.  This would have one end wall open to just sit right up against your existing building.

Another option is to design your first building with a Non-expandable main frame on the end wall.  This would give you the ability to remove the wall when the time comes to expand.  The new building would also have a Non-expandable main frame with an open wall and would sit right up against the current building.  Both Non-expandable frames would carry the loads needed for each building independently.

Are steel buildings expandable, they certainly can be designed to allow for your potential growth.  Be sure to discuss your needs with one of our project managers to weigh out the pro, cons and economics of each option so that you can make an informed decision.

Part of the reason we like to talk to our customers is to understand your needs and help you value engineer the building so that you get the most for your money.  There are many options that are available when it comes to the design of a pre-engineered steel building.  From basic steel building information to steel building bracing, building types and so much more.  Give us a call today to see what we can do for you.
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