Home Additions in Herriman & Riverton: Permits, Pricing & Timeline
What an addition actually costs in Herriman and Riverton in 2026 — primary-suite, great-room, second-story — plus the permit and HOA notes that change the schedule.
Common addition scopes here
Primary-suite additions (bedroom, bath, walk-in closet) are the most-requested scope in both cities — typically 350–500 sq ft, $135k–$240k. Great-room and kitchen-extension additions run $180–$400k depending on whether the roof has to be modified. Second-story pop-tops are rare on these slab-on-grade homes; lateral additions are the default.
Detached ADUs (casitas, in-law units) are increasingly common on the larger lots typical of Herriman and Riverton — $140k–$310k for a standalone 600–900 sq ft unit, depending on finishes and utility runs.
Permit and HOA timeline
Herriman and Riverton both have responsive building departments — 3–5 weeks for residential addition plan review, faster for ADUs on conforming lots. Most subdivisions in both cities have HOA ARC (architectural review committee) requirements for exterior changes — submit drawings, materials, and colors and expect a 2–4 week additional review.
Frequently Asked Questions
- Can I build a detached ADU in Herriman or Riverton?
- Often, yes — both cities allow ADUs subject to lot-size, setback, and parking requirements. We confirm feasibility before pricing the project.
- Is a primary-suite addition cheaper than moving?
- For most Herriman and Riverton homeowners, yes — a $180k addition adds livable square footage and resale value without the friction of selling and re-buying in this market.