The Domicile regulation at http://www.state.vt.us/tax/pdf.word.excel/legal/regs/15811.pdf contains a section on married individuals.  It says: 

It is presumed that the domiciles of a husband and wife or civil union partners are

the same, unless there is affirmative evidence to the contrary. However, spouses who

are separated may acquire separate domiciles, even though no judgment or decree of

separation has been rendered provided the requisite move and intent are present.

Mary Jane Grace, Program Technician

Property Valuation and Review Division

Vermont Dept. of Taxes

802-828-5863

From: Vermont Municipal Government Discussion Network [mailto:[log in to unmask]] On Behalf Of Town of Burke
Sent: Friday, February 05, 2010 11:48 AM
To: [log in to unmask]
Subject: Residential vs Non Residential

Question of the day:  We have a married couple in town, they own two houses.  She lives in one and he lives in the other.  Can they get the residential rate on both.  The two houses are owned jointly by both per the deeds. Sherry/ Burke Listers Office