# CE practice exam 3 question

Hi @coachdarionziegler could you explain to me this answer?
What is the concept of life cycle analysis? I thought this was an estimate of how much it would cost for a building to sustain itself till it need repairs.

I realize that since the stone is thinner than the foundation can need less structure I guess this would be the ideal value engineering option since the other loses thermal mass.

What other derivative value engineering benefits might be generated by this change?

There may be additional life cycle and energy cost savings for the heating and cooling systems, as a function of diminished thermal mass.
Incorrect. The opposite is true: Life cycle heating and cooling costs decrease with increased thermal mass. Thermal mass is the ability of a material to absorb and store heat energy (though, theoretically, it also mitigates the cooling load). An increased amount of energy is required to change the temperature of materials with high thermal mass, such as concrete, bricks, limestone, etc.; however, these materials also maintain their temperature longer. In practical matters, increased thermal mass allows a building to stay colder in warm weather and warmer in cold weather (similar to a cave).

There may be structural concrete savings, as a function of reduced bearing load on the foundation.
Correct. This is simple math; more limestone bearing on the foundation weighs more. If the stone is thinned, the weight is reduced. The engineer now has the option to decrease the depth of the foundation walls, footings, caissons, etc., thus saving concrete costs.

I’ll do my best to assist!

In this case the explanation is just talking about the energy costs over the life cycle of the building. It’s using the term ‘life cycle’ to refer to the life span of the building.

‘Life cycle’ is used a few different terms to mean a couple of different things, so you need to pay close attention when you see those words together!

“Life cycle cost analysis” is used to estimate the cost of maintaining a building throughout its life span.

“Life cycle assessment” is used to determine a building’s environmental impact over the course of the building’s life span.

I know I get these terms confused often… If you run across one of these terms on your exam it might be a great opportunity to use your highlighter tool to emphasize it.

Hope this helps!
-Darion

Ok there’s two different terms, great that helps.