Can I build a second house on my land?

Start with the one rule that does not change at a county line. Virginia's sewage regulations put it this way:

All buildings, residences, and structures designed for human occupancy, employment or habitation and other places where humans congregate shall be served by an approved sewerage system and/or treatment works.

12VAC5-610-80

So a second house is first a sewage question: how it will be served has to be approved, and the health district that takes that application for each locality is listed on the page for the six counties and the City of Galax. How a septic system and its drainfield work is laid out in septic systems explained.

The first house's system can limit where the second one goes. On a lot under Carroll County's subdivision ordinance, drainage fields for onsite septic systems must have a reserve area equal to 50 percent of the required and permitted drainfield, and no structure may be constructed on it, so a second house there cannot sit on the first one's reserve.

After sewage, the answer splits by county, because zoning is optional in Virginia: a locality may classify its territory into districts, and three of the six counties here have not. A zoned county writes its dwelling rules into its districts; an unzoned county, where they exist, writes them somewhere else.

Two counties put the number of homes on the application itself, and one caps lots rather than houses in the rule read for this page.

Grayson County is zoned. Its zoning permit, Form 0100, asks how many residential structures will be located on the tax parcel and whether the application is for a manufactured home. The county's manufactured home replacement form asks whether an older home reset on the same lot can meet the access and density requirements, and the form ties that reset to Articles 3-7 and 3-8 of the Zoning Ordinance; Grayson Planning and Community Development answers the density question for a parcel.

Wythe County has no countywide zoning. Its building permit requirements ask for the number of manufactured homes to be occupied on the total acreage owned, so the county can apply the Mobile Home Park Ordinance of Wythe County. No Wythe rule on a second site-built house was available for this page; the Wythe County Planning Department has the answer.

Montgomery County is zoned under the Montgomery County Zoning Ordinance. In its A-1 Agricultural District the number of lots per parent parcel follows a sliding scale that water and wastewater rules may lower, but how many dwellings one A-1 lot may carry was not among the rules read here. Montgomery County Planning and GIS Services is the office to ask.

Where the rules allow a second dwelling, you still choose how to hold it: both on one parcel, or a division that puts each on its own lot.

• Both on one parcel. One deed and one tax parcel, governed by the locality's second-dwelling rules and the health department's sewage approval. It is the arrangement Grayson's permit counts and Pulaski's conditions describe.
• A lot for a relative. Virginia requires every county's subdivision ordinance to permit a single division for sale or gift to an immediate family member. The terms, access widths and holding periods are in what a family subdivision is in Virginia.
• A lot for an outside buyer. Where a subdivision ordinance applies, no land is subdivided without a plat made and recorded under it. When one of the two houses would go with the sale, the choice is weighed in selling the house with the acreage or separately.

Either way the new house needs its permits, the building permit among them; which ones and in what order is set out in the permits needed to build a house in Virginia. Where both dwellings stay on one parcel, Pulaski requires a second house to be placed to accommodate future division needs, the same layout question a later lot line would raise anywhere.