It depends on what you are calculating. Book value of a company is all of its capital. But if you want book value of the residual equity, you don't include preferred stock. Also, you have to be clear in what you call non-controlling interest. For most corporations with thousands of stockholders, there are thousands of owners who do not have a controlling interest but their ownership is surely a part of book value.
Consider calculating metrics and ratios using both non-controlling interest included in equity and excluded from equity. Then you can see the differences between the two and how the non-controlling interest affects the ratios.
GAAP is pretty clear on how you value a non-controlling interest. If you think you should adjust that valuation because you think the company is lying or something, go to it but you should have some pretty good justification.
when i calculate book value, noncontrolling interest should be whether added or not. i find some finance sites add it and some can't. i don't know if it need to be added.
