The provisions in this Ordinance apply to all land and structures in the unincorporated territory of. Fairfax County. 1103.To establish a domicile in Virginia, you must show you have legal residence in the state with the intent to remain indefinitely. Parents or legal guardians will need to provide the following documents: Proof of Residency in Fairfax County. As per legal dictionary - Definition of Domicile: noun. A person's permanent, fixed, or principal home; noun. Domicile refers to the place you call home permanently. Your domicile is important for legal purposes such as paying taxes, voting, and claiming benefits.