DC Structures
Why ADUs Are Booming in South Carolina
It’s no secret: South Carolina is dealing with shifting home prices and housing supply pressures, and that tension is reshaping what homeowners can realistically build and afford across the state and many local communities. As of late 2025, the average home value estimate in South Carolina was about $299,001 while the statewide median sale price was about $382,900, reflecting continued competition in many markets. Affordability is also a real issue: a significant housing cost burden is reported to impact about 26% of households statewide.
Built for longevity and designed with intention, our Accessory Dwelling Unit (ADU) models offer a practical option to expand a property’s potential without changing neighborhood character or sacrificing main-home living space. South Carolina doesn’t have a single statewide accessory dwelling unit mandate, so accessory dwelling units are generally governed through local zoning and permitting rules that can vary by city and county. Our pre-engineered ADU kits provide a faster, more organized process for high-quality construction, especially helpful in a state where many homeowners still face a patchwork of zoning rules and limited high-level guidance on what’s allowed.
Our ADU Kits
Our pre-engineered ADUs provide a faster, more efficient way to build a backyard family home in South Carolina: Each kit is designed to be custom-tailored to local climate conditions, zoning requirements, and lifestyle needs, and through our customizable accessory dwelling unit models you can tailor everything from layout to bedrooms to finishes, with full plan details and flexible options to create the perfect structure that fits your property and local zoning requirements.
Sitka
SitkaCrafted for backyard use, whether as a guest suite, artist studio, or creative workspace, our Sitka ADU Kit offers limitless flexibility within a compact framework.
Average Cost to Build an ADU in South Carolina
An accessory dwelling unit in South Carolina often lands in a similar range as many accessory dwelling unit projects nationwide—frequently around $150,000 to $350,000, depending on size, scope, and site conditions.
On a per-square-foot basis, 2025 cost breakdowns commonly place accessory dwelling unit construction at roughly $180 to $400 per square foot, with pricing shifting based on preferences, design complexity, labor, and finishes. Variables like site access, foundation work, utility connections, and whether you’re building a new detached structure vs. converting an existing space (like a garage or basement) can significantly change the final price, along with finish selections like a full kitchen, added bathroom, or expanded storage.
South Carolina ADUs
Permitting, Zoning & ADU Regulations in South Carolina
We have an in-house architectural design team that can help align your accessory dwelling unit plans with your city or county’s zoning rules, plus permitting support to navigate local submittals, corrections, and review timelines across South Carolina.
South Carolina does not have one single statewide ADU law that overrides local zoning everywhere. In practice, whether an accessory dwelling unit or tiny house is allowed, and what form it can take (detached, attached, or internal), is typically decided by local ordinances adopted and enforced by municipalities and counties. Where the state does play a major role is building codes. South Carolina’s mandatory building codes are enforced by every municipality and county, and they govern how an accessory dwelling unit must be built from a safety and compliance standpoint (structural, life safety, etc.).
ADU Incentives, Grants & Financing in South Carolina
South Carolina doesn’t have a widely advertised, standing statewide homeowner accessory dwelling unit grant—but there are housing-support and repair programs that can indirectly help move ADU-adjacent projects forward for eligible households. For example, SC Housing’s South Carolina Housing Trust Fund includes various programs which provide financial assistance for essential repairs so low-income homeowners can live safely in their homes (useful when an ADU plan overlaps with major property rehabilitation needs). Additionally, some incentives and support may come through local initiatives funded by programs like CDBG, and qualifying energy-efficiency upgrades may be eligible for a federal tax credit up to $3,200.
Best Cities & Counties to Build an ADU in South Carolina
Charleston
The city has one of the most clearly documented ADU processes in the state, including a step-by-step application workflow and an official accessory dwelling unit application/checklist.
Columbia
Columbia’s zoning materials lay out specific standards for accessory dwelling units, covering basics like owner-occupancy, allowed configurations, and size limits.
Mount Pleasant
Mount Pleasant provides a dedicated ADU requirements document that has key information for anyone looking to build an ADU.
DC Structures
ADU Project Gallery
How ADUs Can Boost Property Value in South Carolina
In high-demand parts of South Carolina, especially coastal markets like the Charleston area, strong renter demand and rising rents can make accessory dwelling units appealing for homeowners who want flexibility and potential rental income. For example, HUD’s Charleston–North Charleston market analysis noted ongoing rent growth, showing an active rental market where added units can still pencil for the right property and location.
Beyond monthly income, an accessory dwelling unit can help offset housing costs and support long-term property value in a market where home prices remain substantial. Redfin reported South Carolina’s median home sale price was $382,900 in October 2025, and Zillow puts Charleston’s typical home value well above that baseline. Adding a functional, independent living space—like a backyard guest house or compact rental—can increase a property’s overall usefulness and buyer appeal when it’s designed to match local demand.
Start Your South Carolina ADU Journey
Ready to bring your ADU vision to life in South Carolina? Our prefab ADU kits come with the plan support, engineering coordination, and delivery help you need to move forward with confidence—especially in a state where accessory dwelling unit rules are typically set locally and can vary by city or county. With expert guidance, clear project details, and help choosing the right model and options, you can make a decision you feel great about.