In any district in which single-unit dwellings are permitted, a single-unit dwelling and customary accessory building may be erected on any single undeveloped lot of record at the effective date of this division or amendments thereto; but
Read it in the chapter →How this ordinance defines it
The operative definition is the local one. Codes routinely subdivide a category into tiers — “day care 2, family”, “group home 2” — and attach different permissions to each, so only Blacksburg’s own text settles what this covers.