ADUs & Guest Houses in St. Augustine & Northeast Florida
Accessory dwelling units, in-law suites, and detached guest houses.
About Our ADUs & Guest Houses Services
Accessory dwelling units are the fastest-growing segment in residential construction — and for good reason. An ADU adds living space, rental income potential, or multigenerational flexibility without buying a second property. Wilson & Co designs and builds ADUs from the ground up: detached guest houses, garage conversions, and attached in-law suites. We handle zoning research, architectural design, permitting, and construction as one team. In St. Johns County, ADU regulations have evolved significantly — we stay current on setback requirements, utility connections, and occupancy rules so your project moves through permitting without surprises.
- Detached guest houses and cottages (up to 1,000+ sq ft)
- Garage-to-living-space conversions
- Attached in-law suites with separate entrance
- Full kitchen and bathroom installations
- Independent HVAC systems for separate climate control
- Separate electrical panels and utility metering options
- ADA-accessible design for aging-in-place applications
- Matching architectural style to primary residence
- Site planning for setbacks, drainage, and parking requirements
- Impact-rated windows and doors for Florida code compliance
Our ADUs & Guest Houses Process
Feasibility
We research your lot's zoning, setbacks, utility access, and local ADU regulations before design begins.
Design
Architectural plans optimized for your lot, including floor plan, elevations, and material selections.
Permitting
We submit to the county and coordinate impact fees, utility connections, and inspections.
Construction
Ground-up build including foundation, framing, MEP, exterior, and interior finishes.
Completion
Final inspections, certificate of occupancy, and turnover.
Frequently Asked Questions
Are ADUs legal in St. Johns County?
Yes, with conditions. St. Johns County allows ADUs in most residential zones with specific setback, size, and parking requirements. We research your specific lot before design.
How much does an ADU cost to build in Florida?
ADUs typically cost $150-$300 per square foot. A 600 sq ft guest house runs $90,000-$180,000. Garage conversions are less — typically $50,000-$100,000.
Can I rent out my ADU?
Rental rules vary by jurisdiction. In unincorporated St. Johns County, long-term rental of ADUs is generally permitted. Short-term rental may have additional restrictions.
How long does it take to build an ADU?
Permitting takes 6-12 weeks. Construction for a detached ADU typically takes 4-6 months. Garage conversions take 2-3 months.
Ready for Your ADUs & Guest Houses Project?
Contact Wilson & Co Design Build today for a free consultation.