Incurable and Curable costs

In calculating the value of private real estate property based on cost approach, I would understand that we deduct the incurable cost from the replacement cost because it can’t be changed and accordingly decreases the value but why do we deduct the curable cost?

Because it will cost you that much to “cure” it?

so it is already included in the replacement cost why shall I deduct it, is not the replacement cost is the cost needed to replace the property with a new one??

Yes Caroline … it is the cost you will bear to establish a “new” property a new means it is flawless of curable and incurable deterioration

So why are we deducting the curable and incurable cost from the replacement cost in that sense?

so the value will be the land+replacement cost (which is a new flawless property), why would I take into consideration the curable and incurable cost and then remove their effect?

You want to value what you currently have.

The replacement cost would tell you what it would cost you to build a new and flawless building to go along with your land. So land + replacement cost is an overstatement of the value of what you actually have (land and not-so-flawless building). The value is overstated by how much it costs you to cure the curable problems and by how much the incurable problems lower the value of your building (in comparison to a flawless one).

That is the reason the replacement cost is a new flawless property and yours is not … so you need to take the value of this new property down to match the (old) property you are evaluating now