D.C. Mun. Regs. tit. 14 § 104
Any duly designated agent of the District of Columbia may enter the premises of a housing business at all reasonable hours, for the purpose of enforcing this section, except as limited by other provisions of this section.
The District, both prior to the issuance of a housing business license and during the license period, may, at all reasonable hours, enter and inspect the premises occupied or to be occupied by a housing business, except as provided in subsection 104.3.
If it appears that any portion of a premises is under the exclusive control of a tenant, or if the operator of a housing business so claims, the housing inspector shall not enter that portion of the premises without first having obtained permission from the tenant or the tenant's agent, except as provided in § 104.4.
If a tenant of a housing business does not give permission to inspect that portion of the premises under the tenant's exclusive control, the housing inspector shall not enter that portion of the premises unless said inspector has:
When a duly designated agent of the District of Columbia presents a valid administrative search warrant that permits inspection of the premises under a tenant's exclusive control, the tenant of a housing business who refuses to give permission to inspect that portion of the premises shall be in violation of this section.
The refusal of any tenant to permit such an inspection shall not result in a revocation or suspension of the housing business, nor shall such refusal result in the assessment of penalties against the operator of a housing business license.
D.C. Mun. Regs. Tit. 14, § 104