Generational Suitesby Watermark Design Build
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Archetype B · Detached

The Casita

A build-ready detached guest house, pre-engineered and permit-tested

Planning range

$120,000 – $155,000

Vertical construction plus our standard finish package. Site prep and utility runs are scoped separately during feasibility.

Configuration
1 bedroom / 1 bath, detached
Footprint
20′ × 24′ · 480 sq. ft.
Budget basis
$120,000 – $153,600 at 480 sq. ft.
Setback tier
Habitable — 10′ typical

Standard layouts

The Casita

20′ × 24′ · 480 sq. ft.

One bedroom, full kitchen, walk-in shower, and a covered entry. The smallest footprint that still lives like a real home — and the one that most often fits inside a standard setback envelope.

Build ready means the design phase is already done

The Casita is a pre-engineered structural shell. The framing, truss layout, wind-load package, and mechanical routing are already drawn and already reviewed, so your project starts at permitting instead of starting at a blank page.

You still choose siding, roof color, flooring, cabinetry, tile, and fixtures. What you skip is the four-to-eight week custom design cycle and the engineering fees attached to it.

  • Fits inside standard 10-foot habitable setbacks on most suburban parcels
  • Sits comfortably under the 900 sq. ft. accessory caps used across unincorporated Hillsborough and Pasco
  • Exterior is matched to your main house so it never reads as a shed

The Florida site-work caveat

Detached means new utilities. Site prep, tree clearing, and water, sewer, and electrical trenching — or septic drainfield expansion where there is no sewer — are estimated separately during the feasibility phase, once we know your actual grade, tree canopy, and tap locations.

We would rather show you that line item honestly than bury it in a headline price and revise it later. Run your address through the property check and we will tell you what your parcel implies before anyone signs anything.

What the range includes

  • Pre-engineered structural and wind-load package
  • Foundation, framing, roof, and dry-in
  • Full kitchen, bath, HVAC, and standard finish package
  • Permitting and inspections through your jurisdiction

Estimated separately

  • Site clearing, tree removal, and grading
  • Water, sewer, and electrical lateral trenching
  • Septic drainfield expansion where applicable
  • Pavers, walkways, and landscape restoration

Features most often added

Added inside the same design and permit set — never as a second project with a second contractor.

  • 1-Car Garage10′ × 20$19k–$27k
  • Pergola12′ × 16$11k–$16k
  • Therapy Spa7′ × 7$18k–$30k
  • Storage Shed8′ × 12$7.7k–$12k
  • Summer Kitchen6′ × 14$18k–$42k

Placeholder planning ranges for budgeting only — not a quote. Final pricing depends on site conditions, utility runs, finishes, and permitting.

Next step

Check whether the casita fits inside your buildable envelope.

Check my property