USA Capitalization of preliminary design for building expansion

[Jacqui]

Hi, my company is looking to expand one of our manufacturing facilities and we're trying to figure out whether preliminary/conceptual designs can be capitalized into the building cost or if they must be expensed. All I'm finding online is that if the project is probable, preliminary costs directly related to the project can be capitalized. However, the controller is questioning the fact that it is being talked about as "preliminary" and "conceptual." Since this could result in multiple designs in which only one ultimately gets finalized, his inclination is that it should all be expensed until there is a final design in place. I'm trying to find guidance to either confirm or refute this. Does anyone have any input on how this should be handled? If you know where to find guidance in writing, please include it. Thanks!