ADU Construction Services by Nunley Custom Homes in Greenville, SC
Accessory Dwelling Units (ADUs) have become a practical solution for homeowners looking to add living space, generate rental income, or accommodate multigenerational families — all without relocating. Nunley Custom Homes is an experienced ADU contractor based in Greenville, SC, bringing over 34 years of construction expertise to residential projects across the Upstate region.
These secondary units — sometimes called in-law suites, carriage houses, or granny flats — can be built as detached structures or attached directly to the primary residence. With Greenville County's growing population and increasing housing demand, ADUs represent a flexible, long-term investment for many homeowners.
As a full-service ADU builder, Nunley Custom Homes handles the entire process, from initial design through permitting, construction, and final handover.
Types of ADUs Nunley Custom Homes Builds
Every property has different needs, and Nunley Custom Homes works with homeowners to identify the right type of unit for their goals, budget, and lot configuration. The following ADU types are available:
- Detached ADUs: Stand-alone structures built separately from the main home. These backyard cottage or Casita-style units offer full privacy and are well-suited for rental income or use as an in-law suite.
- Attached ADUs: Units connected to the primary residence while maintaining a separate living space. These integrate with the home's existing architecture and are a practical option for families wanting proximity without sacrificing privacy.
- Garage Conversions: As a garage conversion contractor, Nunley Custom Homes can transform underused garage space into livable units, or construct a new ADU above an existing garage. Above-garage ADUs preserve yard space while providing rental or guest accommodations.
- Basement & Attic ADUs: When outward expansion isn't feasible, converting a basement or attic into a functional living space is a cost-effective alternative that doesn't alter the home's exterior footprint.
Construction styles vary as well. Nunley Custom Homes offers modular ADUs for faster timelines and predictable costs, stick-built ADUs for full customization and architectural integration, tiny home-style units for compact and efficient living, luxury ADUs with high-end finishes, and sustainability-focused designs incorporating energy-efficient insulation, solar panels, and passive solar orientation.
In Greenville, SC, ADU construction costs typically range from $150 to $400 per square foot, depending on unit type, materials, and design complexity. General cost ranges include:
- Attic ADUs: $50,000 – $100,000
- Above-garage ADUs: $75,000 – $150,000
- Detached ADUs: $100,000 – $250,000
Factors influencing cost include size and layout, structural work required, finish selections, utility integration, and permitting fees. Nunley Custom Homes provides itemized estimates so homeowners have a clear picture of expected costs before construction begins.
Permitting, Zoning, and the Construction Process
Building an ADU in Greenville County involves navigating local zoning regulations, setback requirements, lot coverage rules, and HOA approvals. Nunley Custom Homes manages this permitting process on behalf of homeowners, coordinating inspections for plumbing, electrical, and structural compliance with South Carolina building codes.
Key regulatory considerations include:
- ADUs cannot exceed 50% of the primary dwelling's floor area — for example, a 2,500 sq. ft. home allows a maximum 1,250 sq. ft. ADU.
- Height limits, property line setbacks, and lot coverage rules apply under Greenville County zoning.
- HOA covenants and design guidelines must be reviewed and addressed prior to construction.
- Plumbing, electrical, and structural inspections are required to meet state building codes.
The construction process follows four main stages: an initial consultation and design phase, permit acquisition and compliance review, active construction, and a final walkthrough before handover. Smaller ADU projects may take 2–3 months, while larger or more complex builds can extend to 6 months or more.
Nunley Custom Homes serves homeowners throughout Greenville County looking for a reliable accessory dwelling unit builder with experience in local regulations, diverse construction styles, and a range of ADU types suited to different property configurations and lifestyle needs.