ADU Cost Calculator - Simpsonville & Upstate SC
C. Scott Burch
Owner & Lead Contractor
30+ years | 12 ADUs built
Last updated
Apr 19, 2026
ADU Cost Calculator
Estimate the cost of building an accessory dwelling unit (ADU) - from simple garage apartments to fully detached backyard cottages with kitchen, bath, and living space.
Pricing Data Updated: April 2026 — Reflects current Upstate SC market rates, material costs, and labor pricing.
Budget Planning Disclaimer
This calculator is for planning only and includes a fixed 20% contractor markup in every estimate. Final pricing varies based on existing conditions, structural work, framing changes, plumbing or electrical upgrades, finish selections, permit requirements, and actual scope. We recommend using this as a starting range, then scheduling a site visit for a written estimate.
Choose Your Project
Estimate Snapshot
Planning range: $62,700 to $89,100 (includes 20% contractor markup). Final pricing will depend on site conditions, selected products, and scope confirmation.