Is leasing a building equivalent to having a company finance a project's construction via a long-term book?

No, leasing a building is not equivalent to having a company finance a project's construction via a long-term book.

Leasing a building typically refers to the act of renting or leasing space in a pre-existing building owned by another party. In this case, the lessee (the company or individual renting the space) pays regular rent to the lessor (the owner of the building) in exchange for the right to use and occupy the building for a specified period of time. The lessee does not own the building, but rather has the temporary right to use it for their business operations.

On the other hand, financing a construction project via a long-term "book" typically refers to obtaining financial support from a bank or other financial institution to fund the construction of a new building or infrastructure project. In this scenario, the company seeking to construct the project is borrowing money from the bank, and the loan is usually repaid over an extended period of time, often several years or even decades. The company becomes the owner of the newly constructed building or infrastructure project once it is completed.

Therefore, leasing a building involves renting a pre-existing space, while financing a construction project involves obtaining a loan to fund the creation of a new building or infrastructure. They are separate concepts with different implications and ownership arrangements.