> Can an incomplete and unsafe building be rented to a tenant on a
> commercial lease if the building never received a certificate of
> occupancy?

Probably yes. 

**The General Rule**

In commercial leases, to a much greater degree than in residential leases, the principle of buyer beware (a.k.a. *caveat emptor*) applies. Commercial leases are typically negotiated between sophisticated parties, and if the tenant doesn't want to start paying rent until the certificate of occupancy is issued despite a lease that says otherwise, then that is tough luck and the tenant is bound to the terms of the lease. 

Many states have statutory or common law implied warranties of habitability in the case of residential leases. And, New Mexico, in particular, has [many statutory protections for residential tenants][1] (statutes found [here][2]). But, almost none of these protections extend to commercial leases, because commercial leases are not leases of [dwelling units][3], as defined in the relevant statutes.

**Examples Of Situations Where This Would Not Be Required In A Fair Deal**

Most commercial tenants insist upon terms that say that the obligation to pay rent starts when a certificate of occupancy is issued and the tenant is allowed to take possession of the premises. But, there would certainly be some times when a commercial tenant would pay rent on property that does not yet have a certificate of occupancy.

For example, in what is called a "pad rental", a business rents a basically vacant lot with only a concrete foundation and utility hookups and zoning approvals in place, and then the tenant builds a shop or office building on the pad. In those commercial leases, typically a tenant would start paying rent immediately and the length of time needed to get the tenant's shop built and approved for occupancy by local government officials is their problem.

Something very similar is done in an existing building that requires tenant finish. At one extreme, the landlord will do tenant finish to the tenant's specifications at the landlord's expense and the tenant will only start to pay rent when the tenant takes occupancy. At the other extreme, the tenant will start paying rent immediately and do the tenant finish at the tenant's sole expense. In between, the tenant may do the tenant's own tenant finish pursuant to landlord approved plans, with the landlord contributing a tenant finish allowance that will often be less than the full anticipated cost of tenant, and the rent will be reduced or waived for a set period of time which may or may not correspond to the actual time that it takes to complete the tenant finish.

In yet another example, it wouldn't be terribly uncommon for a landlord to rent a commercial space that is already occupied by squatters or holdover tenants, to a new tenant on a triple net basis under which the tenant is responsible for evicting the current occupants, rather than the landlord.

**Conclusion**

It all boils down to the terms of the lease and a reasonable construction of the relevant lease terms.

The fact that there is such a thin amount of legal protection from unfair lease terms is one of the reasons that most commercial tenants hire an attorney to help them negotiate the terms of a commercial lease, in addition to, or instead of, a commercial real estate broker.


  [1]: https://www.nolo.com/legal-encyclopedia/overview-landlord-tenant-laws-new-mexico.html
  [2]: https://law.justia.com/codes/new-mexico/2006/nmrc/jd_ch47art8-10333.html
  [3]: https://law.justia.com/codes/new-mexico/2006/nmrc/jd_47-8-3-106fb.html