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An unused garage or a half-finished basement is easy to overlook. In Henrico County right now, it might also be one of the more overlooked ways to add real rental income to a property you already own.
Accessory dwelling units are having a real moment in Virginia, and Glen Allen owners have more room to act on that than most people realize.
We help Glen Allen owners think through this kind of value-add decision, so here is what the current rules allow, what is about to change, and how to decide whether it makes financial sense.
Key Takeaways
- Henrico County already permits an accessory dwelling unit by right for a single-family detached home, without a public hearing, under County Code Section 24-4406.
- The unit is capped at the lesser of 800 square feet or 35 percent of the main home's finished floor area, which usually means the percentage rule limits your project.
- A garage conversion or an interior basement unit typically qualifies as an attached ADU, while a detached structure like an apartment over a garage falls under separate siting rules.
- Virginia's Senate Bill 531, signed in April 2026, will require every locality in the state to allow ADUs by right starting July 1, 2027.
- Short-term rental use is not permitted for a Henrico ADU, so this is a long-term rental income strategy, not a vacation rental play.
What Henrico Already Allows Today
Under Henrico County Code Section 24-4406, an accessory dwelling unit is already permitted by right as long as it is accessory to a single-family detached home. That means no special use permit and no public hearing, as long as your project fits within the size and siting rules.
The size cap is what trips people up. The unit cannot exceed 800 square feet or 35 percent of your main home's finished floor area, whichever is smaller. On a typical 2,000-square-foot Glen Allen home, that math works out closer to 700 square feet, meaning the percentage rule usually binds before the flat 800-square-foot ceiling does.
Garage Conversion vs. Basement Conversion
A garage conversion or basement buildout generally counts as an attached or interior ADU, which is usually the simpler path because it skips the additional siting requirements that apply to a detached structure.
A detached unit, like an apartment above a garage, still qualifies but has to respect specific distance requirements from your main home, other structures, and property lines. For most Glen Allen lots, an attached garage or basement conversion is the more straightforward starting point.
The Parking and Occupancy Details
Henrico requires one additional off-street parking space for the ADU, and the unit cannot be used for short-term rental. This is meant to function as a long-term housing unit, whether for a family member, a tenant, or eventually a full rental once the space is complete.
Unlike some neighboring jurisdictions, Henrico's ordinance does not appear to require the occupant to be a family member, though it is worth confirming the current owner-occupancy language directly with the county before finalizing plans, since local rules can be updated.
The Bigger Change Coming in 2027
Governor Glenn Youngkin's successor, Governor Abigail Spanberger, signed Senate Bill 531 in April 2026, a law that will require every locality in Virginia to allow ADUs by right in single-family residential zones starting July 1, 2027.
For Henrico, which already allows ADUs by right, this may not change much day to day. But the new law is also expected to limit how much localities can restrict ADUs through fees and setback rules, and it will prohibit family-relation occupancy requirements outright. If you have been waiting for more certainty before committing to a project, this law adds real momentum toward ADUs becoming a permanent, protected option statewide.
What This Actually Costs
Conversion costs vary widely depending on scope. A basement conversion tends to run on the lower end since plumbing and structural work are often less extensive, while a full detached new build costs considerably more because of the foundation, roofing, and standalone utility work.
Before committing to a specific approach, run the numbers on what a converted unit could realistically rent for in Glen Allen against your expected conversion cost. Our ROI calculator can help you compare that potential rental income against the upfront investment.
What to Confirm Before You Start
Check your HOA covenants first, since many Henrico neighborhoods maintain stricter rules on materials, setbacks, and dimensions than the county itself requires. Confirm septic capacity if your property is not on public utilities, since western and rural portions of the county are more likely to need that review.
Henrico's permitting process is generally efficient, often taking one to three weeks once you submit a complete application, but you must include a detailed site plan showing property lines, existing structures, easements, and exact project dimensions, regardless of how you submit.
Frequently Asked Questions
Do I need a special permit to build an ADU in Henrico County?
No. Henrico allows an ADU by right for a single-family detached home, meaning no special use permit or public hearing is required, as long as the project meets the size and siting rules.
How big can a Henrico ADU actually be?
The unit is capped at the lesser of 800 square feet or 35 percent of your main home's finished floor area. On most standard Glen Allen homes, the percentage limit is the binding number.
Can I rent my ADU out short term?
No. Henrico's ordinance does not permit short-term rental use of an ADU, so this works as a long-term rental income strategy rather than a vacation rental option.
Will Virginia's new ADU law change anything for Henrico specifically?
Since Henrico already allows ADUs by right, the immediate impact may be limited, but the law will also restrict how much localities can charge in fees or impose in setback requirements once it takes effect in July 2027.
Should I check with my HOA before starting an ADU project?
Yes. Many Henrico HOAs maintain stricter rules on ADU materials and dimensions than the county itself, so confirming HOA approval first can save significant time and cost.
Let Us Help You Evaluate the Investment
An ADU conversion can turn an underused garage or basement into a real, ongoing source of rental income, but the right approach depends on your specific property, lot, and budget.
At Relevate Property Guides, we help Glen Allen owners evaluate whether a conversion project makes financial sense before committing to construction. If you are considering this move, request a free rental analysis or explore our owner resources to see how we help owners think through value-add decisions like this one.
