Accessory Dwelling Units (ADUs) come in several common types: detached backyard units, garage conversions, carriage houses, attached garage-connected ADUs, basement apartments, and full-scale home additions. Each serves different needs depending on space, structure, and zoning. This guide outlines each type and explains what’s permitted in your area.
Compact home additions are becoming one of the most flexible and practical solutions for homeowners looking to expand livable space. Whether you're housing aging parents, accommodating adult children, or planning for guests, the type of ADU you choose will depend on your property, your goals, and local zoning laws.
In this post, we’ll walk through the most common types of ADUs—including garage-based options—and break down which types are allowed in your service area: Cary, Raleigh, Wake Forest, and Holly Springs.
Let’s begin by understanding the most common types of ADUs—how they work and why homeowners choose them..
Detached ADUs are standalone structures built separately from the primary residence. These include:
These are often built in the backyard and serve as fully independent living spaces. They include kitchens, bathrooms, and private entrances.
Allowed In: Cary (as of June 2024), Raleigh, Wake Forest, and Holly Springs
A garage conversion ADU is built by converting an existing attached or detached garage into a legal, livable space. This is often the most cost-effective type of ADU since it repurposes the existing structure.
Features include:
Allowed In: Cary, Raleigh, Wake Forest, Holly Springs (with code compliance)
An above-garage ADU—sometimes called a carriage house—sits on top of a garage. This option saves yard space and is ideal for homeowners who want to preserve green space or parking.
Typical uses:
Allowed In: Raleigh, Wake Forest, Holly Springs. Cary—case by case approval
This ADU is built adjacent to a new or existing garage and may share a wall or breezeway with the garage structure.
It’s ideal for:
Allowed In: All four cities, subject to lot size and coverage limits
Basement ADUs convert the lower level of a home into a self-contained unit. This includes:
While basement units are practical, they depend heavily on your home’s existing structure and basement height.
Allowed In: Raleigh, Wake Forest. Holly Springs and Cary—limited or rare due to lot and elevation restrictions
Some homeowners expand their homes by building an attached wing that functions as an ADU. This can be a:
These are treated as permanent additions and must meet all residential building codes.
Allowed In: All service areas with proper permits and design review
Understanding local limitations is just as important as knowing what's possible. While many types of ADUs are permitted, zoning rules in each area place restrictions on certain configurations. Here's what’s typically not allowed in our service area:
All ADUs must serve residential purposes only and be part of a single-family property use
Planning a backyard build or garage conversion? Here’s a quick guide to which ADUs are allowed in your city.
Keep in mind that local zoning can change. It’s always best to speak with a contractor or city planner before moving forward with your project.
If you’re ready to explore adding an ADU to your property, working with a trusted Raleigh ADU builder is the first step. Whether you’re still gathering ideas or ready to start planning, it’s smart to speak with someone who understands both the construction and the permitting side.
Schedule a consultation with an accessory dwelling unit contractor who knows how to build efficiently, stay on budget, and help you get the most from your space.
