City of Chino Timeline

Phase 1: Site Assessment and Pre-Design (Weeks 1–3)

City of Chino site assessment covers: lot dimensions and setbacks, clay-adobe soil assessment (expansive soils are common across City of Chino — a soils report is often warranted), utility locations (Chino Basin Water District or IEUA water, city sewer, SCE electrical), HOA status (The Preserve and other tract developments), and fire zone check. City of Chino's flat terrain simplifies site access and utility runs compared to Chino Hills, but the clay-adobe soils require early attention.

Phase 2: Design and Engineering (Weeks 2–8)

Architectural design for City of Chino ADUs follows standard planned community development design practices. The Preserve HOA (if applicable) has ARC standards that must be incorporated into design simultaneously with city permit plans. Structural engineering and Title 24 energy compliance run concurrently. If a soils report indicates expansive clay conditions, foundation engineering is modified accordingly — typically a post-tensioned slab or deepened conventional slab.

HOA ARC submittal (Week 4–5, parallel): for The Preserve and other City of Chino HOA communities, ARC submittal runs concurrent with city permit submission. We coordinate both simultaneously.

Phase 3: Permit Submittal and Plan Check (Weeks 8–18)

Submittal to City of Chino Development Services, 13220 Central Ave. Plan check: 6–10 weeks. IEUA or Chino Basin Water District connection application filed simultaneously. City of Chino does not have a pre-approved plan fast-track as of 2025.

City of Chino Hills Timeline

Phase 1: Geotechnical Assessment — Start Here (Weeks 1–4)

For hillside Chino Hills lots, geotechnical investigation starts before architectural design. This is not optional — it's the only way to design a foundation that won't require revision after submittal. A geotechnical investigation on a Chino Hills hillside lot typically takes 2–3 weeks for fieldwork and report delivery, costs $3,500–$7,000, and produces the soil bearing data the structural engineer needs to design the foundation. Starting this on week 1 keeps it from blocking the design phase.

For flat Chino Hills lots in The Preserve or newer developments, standard soils assessment during design is sufficient — full geotechnical investigation may not be required.

Phase 2: Design and Engineering (Weeks 3–10)

Chino Hills ADU design must address fire zone requirements for VHFHSZ parcels: Class A roof assembly, ember-resistant vents, multi-pane windows, fire-resistant exterior cladding per CBC Chapter 7A. These requirements are incorporated into the architectural plans and structural specifications. Designs that don't include Chapter 7A compliance on VHFHSZ parcels will receive a first-round plan check correction — adding 4–6 weeks. We include fire zone compliance from the design stage.

Phase 3: Permit Submittal and Engineering Review (Weeks 10–22)

Submittal to City of Chino Hills Planning Department, 14000 City Center Dr. Standard plan check: 6–10 weeks. Additionally, Chino Hills Engineering Department conducts a parallel review for hillside grading and drainage standards — this adds 2–4 weeks to the review timeline but runs concurrently with planning review, not sequentially. Water connection application to Chino Hills Water District filed simultaneously.

HOA ARC submittal for Butterfield Ranch, The Preserve (Chino Hills portion), and other HOA communities: submitted in parallel with city permit application.

Phase 4: Construction (Weeks 18–40)

City of Chino construction is similar in timeline to other planned community markets. Chino Hills hillside construction adds: retaining wall construction (if required by geotechnical report), slope stabilization, potentially more complex foundation installation, and fire-resistant exterior construction per Chapter 7A. Each adds time relative to flat-lot construction. Budget 6–10 additional construction weeks for complex hillside projects.