Hillsborough — Design Review

Last reviewed: July 2, 2026

Overview

Design review in Hillsborough is administered through the Hillsborough Zoning Ordinance (Title 17) and routed primarily through the town's Architecture and Design Review processes referenced in Chapter 2.12. Design review is a mandatory step for specific projects (for example certain landscaping, ADU exceptions, large homes, and projects following a variance) and is used to confirm neighborhood compatibility, compliance with design guidelines, and the town's development standards. Key triggers and standards are set out across Title 17: permitting triggers in the ADU chapter, landscaping chapter, setbacks/height/FAR chapters, and variance rules — with procedural detail referenced to Chapter 2.12 (the design‑review procedure) which the code repeatedly invokes. § 17.56.060, § 17.52.050, § 17.32.040, and § 17.40.020 are the primary locally controlling cites.

Below I synthesize what the Hillsborough ordinance actually requires about design review, district applicability, triggers, and practical next steps. Where the code points to Chapter 2.12 for procedure, I note that the chapter is referenced but the detailed Chapter 2.12 text was Not found in retrieved materials — verify with the jurisdiction.

What the code says — triggers, authorities, and limits

• The code requires design review for certain landscaping projects: landscaping items listed at § 17.56.050 must receive design review approval per § 17.56.060 (design review proceeds under Section § 2.12.070).

• An Accessory Dwelling Unit (ADU) or Junior ADU (JADU) that does not meet all local ADU standards may be permitted only after undergoing the design review process in Chapter 2.12; the ADU exception review and required findings are set out in § 17.52.050. An ADU that conforms fully to § 17.52.020 can be approved ministerially without discretionary design review.

• Very large single‑family dwellings (new primary dwellings with total covered floor area in excess of 8,000 sq ft) must be submitted to the city council after architecture and design review per § 17.32.040; the council holds a public hearing and can approve, conditionally approve, deny, or send the project back for redesign.

• When the city grants a variance, the owner must apply for design review approval consistent with that variance under § 17.40.020.E.

• The code defines building envelope, height, setback, FAR and lot‑coverage rules (which design review will evaluate for visual compatibility even where standards are objective). Key development standards referenced by design review include: street‑line setback 25 ft (see § 17.24.020), the building envelope/height plane (see § 17.28.010), and FAR/lot‑coverage (see § 17.32.030).

• The ordinance distinguishes type or notice levels for design review (the code repeatedly cites § 2.12.070 and Chapter 2.12 for “type B” projects, public notice requirements, and appeal procedures), but the governing Chapter 2.12 text that defines the procedural types and timelines was Not found in retrieved materials. Verify Chapter 2.12 for exact application processing times, noticing thresholds, and appeal routes.

District-by-district breakdown (where design review applies)

The code reorganized Hillsborough’s zones into residence districts. The district names and permitted uses are set out in § 17.12.010 and § 17.16.010; design review is applied across these districts where the triggers above occur.

• RD-1 — Traditional Residential

  • Purpose: preserve single‑family character; maximum density one single‑family dwelling per one‑half acre (exclusive of ADUs). § 17.16.010(A)(1).
  • Typical permitted uses: single‑family dwellings, accessory structures, country club (on designated sites), public parks, town facilities (where allowed), and ADUs; some uses require special permit (e.g., private schools) per § 17.16.010(B).
  • Key dimensional standards (applies townwide unless otherwise modified): front/street‑line setback: 25 ft (see § 17.24.020); interior setback area 20 ft; height limited by the building envelope starting at 22 ft then 45° plane to a 32 ft maximum as described at § 17.28.010; FAR and lot coverage limits in Chapter 17.32 (see § 17.32.030 and § 17.32.060). Design review will check aesthetic compatibility against these standards.
  • Where applied: all RD‑1 parcels shown on the town zoning map; design review comes into play for large homes, ADU exceptions, landscaping projects listed in § 17.56.050, and when a variance is needed.

• RD-2 — Mixed Residential

  • Purpose: accommodate townhomes and multifamily where the town has designated those parcels; minimum density 20 units/acre on sites so zoned § 17.16.010(A)(2).
  • Typical permitted uses: multi‑family housing, public parks/playgrounds, town facilities, ADUs, certain institutional uses (some on special permit). § 17.16.010(B) lists specific uses and special‑permit items.
  • Key dimensional standards: underlying townwide setbacks, height plane, FAR/lot coverage rules apply; ADU rules (setbacks, parking exceptions, architectural matching) also apply in RD‑2 per Chapter 17.52 for ADUs. Design review is required for ADU exceptions and certain landscaping/large‑scale renovations.

• RD-3 — Governmental and Residential Mixed Use

  • Purpose: limited residential and town facilities on identified town‑owned land; cap of 16 dwelling units in this district as identified in § 17.16.010(A)(3).
  • Typical permitted uses: town facilities, public buildings, limited multi‑family housing where explicitly designated, ADUs where allowed, and associated public uses.
  • Key dimensional standards: townwide standards (setbacks, height plane, FAR) still govern; design review will be used for major changes to town facilities and for projects subject to ADU exception review or variance.

Table — selected decision‑relevant permitted uses and standards (excerpt)

How design review is used in practice (plain‑English synthesis / guidance)

• Design review in Hillsborough is both procedural and substantive: for certain project types the code requires a design‑review approval before building permits can be issued (e.g., the landscaping categories listed in § 17.56.050 must get design review approval before building permits, per § 17.56.060) and for other projects design review is the path by which exceptions (like ADU exceptions or approvals following a variance) are vetted.

• Expect design reviewers (the Architecture and Design Review Board and/or the planning staff and sometimes the city council) to evaluate compatibility with the town’s residential design guidelines, neighborhood character, and the objective development standards (setbacks, building envelope/height, FAR, lot coverage). See § 17.52.050 (ADU exception findings require consistency with the general plan and residential design guidelines) and § 17.32.040 (city council review for very large homes).

• The code repeatedly defers procedural specifics (timing, notice types, Type A/Type B categorization, appeals) to Chapter 2.12 and to Section 2.12.070. Because the Chapter 2.12 procedural text was Not found in retrieved materials, applicants must verify the timeline, noticing method, and appeal windows directly with the planning office. Notably the ADU exception rules explicitly require a “type B” public notice under § 2.12.070.A.

Checklist — what an applicant must satisfy (quick list)

• Confirm whether your parcel is in RD‑1, RD‑2, or RD‑3 (zoning map) and the uses allowed there § 17.12.010, § 17.16.010.
• Determine whether your project is one of the triggers for design review:
  • ADU that does not meet § 17.52.020 → ADU Exception / design review required (§ 17.52.050)
  • Landscaping items identified in § 17.56.050 → design review required (§ 17.56.060)
  • New primary dwelling > 8,000 sq ft → ADRB + city council review (§ 17.32.040)
  • Any approval following a variance granted by the council → design review under Chapter 2.12 (§ 17.40.020.E)
• Prepare plans that show compliance with objective standards: setbacks (§ 17.24.020), height and building envelope (§ 17.28.010), FAR/lot coverage (Chapter 17.32).
• For ADUs, include the specific ADU materials required by Chapter 17.52 (architectural matching, parking rules/possible exceptions, landscape screening) and be prepared for either ministerial approval (if it meets all standards in § 17.52.020) or design review if it needs exceptions § 17.52.020–050.
• Ask planning staff for the applicable Chapter 2.12 application form, the notice type (Type A/Type B), the public hearing/meeting schedule, and fee amount (Chapter 2.12 details were Not found in retrieved materials). Verify submittal and noticing requirements with the planning department.
• If your project may involve protected trees, significant grading (>50 cu yd) or large landscaping changes, include a landscape plan meeting § 17.56.040–070 and be ready to post security/bonds if required § 17.56.080.

Risks & Ambiguities

Plain‑English Summary

If your project changes the look or layout of a property in ways the code flags — for example removing protected trees, building an ADU that needs exceptions, constructing a very large home, or building after a variance — Hillsborough requires design review. The ordinance points to Chapter 2.12 for the procedure but sets the substantive standards for what the design reviewers check (setbacks, height, FAR, landscaping, and matching the character of the neighborhood). Expect to provide plans showing compliance with setbacks (25 ft front), the height/building envelope rules, FAR/lot coverage calculations, and any ADU architectural/landscape details required by Chapter 17.52. Verify procedural timing and notice type with planning because Chapter 2.12 procedural text was Not found in the retrieved materials.

Source References

• Hillsborough Zoning Ordinance (Title 17) — General title and purposes; zoning map rules: § 17.04.010–030.
• Zoning districts established and names: § 17.12.010 (RD‑1, RD‑2, RD‑3).
• Permitted uses table and district purposes: § 17.16.010 (RD‑1/RD‑2/RD‑3).
• ADU general provisions, architectural requirements, parking, and ADU exception: § 17.52.020, § 17.52.050.
• Landscaping triggers and design review obligation: § 17.56.050–070 (design review per § 2.12.070).
• Setbacks & measurement (street‑line 25 ft; interior 20 ft): § 17.24.020–030.
• Height/building envelope: § 17.28.010.
• FAR, lot coverage, and very large homes (8,000 sq ft triggers): Chapter 17.32, especially § 17.32.030 and § 17.32.040.
• Variance and design review linkage: § 17.40.020.E.
• Parking for ADUs / second units: § 17.36.035 and ADU parking exceptions in Chapter 17.52.

NOTE: Chapter 2.12 (the detailed design‑review procedure and the content of § 2.12.070) is repeatedly referenced by the sections above but the full Chapter 2.12 text and the detailed language of § 2.12.070 were Not found in retrieved materials. For procedural details (notice types, exact timelines, appeal steps, “type B” vs. “type A” thresholds) obtain Chapter 2.12 from the town's municipal code or the planning office.

Retrieved passages

• Hillsborough Zoning Code (§ 3) High relevance show source text
• Hillsborough Zoning Code (Section 17.52.020) High relevance show source text
• Hillsborough Zoning Code (Section 17.56.050) High relevance show source text
• Hillsborough Zoning Code (§ 26) Medium relevance show source text
• Hillsborough Zoning Code (Section 65915) Medium relevance show source text
• Hillsborough Zoning Code (section 66333) Medium relevance show source text
• Hillsborough Zoning Code (§ 3) Medium relevance show source text
• Hillsborough Zoning Code (Chapter 17.54) Medium relevance show source text
• California Fire Code Medium relevance show source text
• Hillsborough Zoning Code (§ 16) Medium relevance show source text
• Hillsborough Zoning Code (Section 21155) Medium relevance show source text
• Hillsborough Zoning Code (Chapter 2.12) Medium relevance show source text
• Hillsborough Zoning Code (chapter or) Medium relevance show source text
• Hillsborough Zoning Code (chapter must) Medium relevance show source text
• Hillsborough Zoning Code (Section 17.32.030) Medium relevance show source text
• Hillsborough Zoning Code (§ 2) Medium relevance show source text
• Hillsborough Zoning Code (section is) Medium relevance show source text
• Hillsborough Zoning Code (Chapter 2.12) Medium relevance show source text
• Hillsborough Zoning Code (chapter to) Medium relevance show source text
• Hillsborough Zoning Code (section is) Medium relevance show source text
• Hillsborough Zoning Code (Section 801.5) Medium relevance show source text
• Hillsborough Zoning Code (§ 4) Medium relevance show source text
• Hillsborough Zoning Code (§ 16) Medium relevance show source text
• Hillsborough Zoning Code (section are) Medium relevance show source text
• Hillsborough Zoning Code (Section 15.24.020) Medium relevance show source text
• Hillsborough Zoning Code (Section 17.24.030) Medium relevance show source text

Cited sections

• Hillsborough Zoning Ordinance (Title 17) — General title and purposes; zoning map rules: **§ 17.04.010–030**. (Title 17)
• Zoning districts established and names: **§ 17.12.010** (RD‑1, RD‑2, RD‑3). (§ 17.12.010)
• Permitted uses table and district purposes: **§ 17.16.010** (RD‑1/RD‑2/RD‑3). (§ 17.16.010)
• ADU general provisions, architectural requirements, parking, and ADU exception: **§ 17.52.020**, **§ 17.52.050**. (§ 17.52.020)
• Landscaping triggers and design review obligation: **§ 17.56.050–070** (design review per **§ 2.12.070**). (§ 17.56.050)
• Setbacks & measurement (street‑line 25 ft; interior 20 ft): **§ 17.24.020–030**. (§ 17.24.020)
• Height/building envelope: **§ 17.28.010**. (§ 17.28.010)
• FAR, lot coverage, and very large homes (8,000 sq ft triggers): **Chapter 17.32**, especially **§ 17.32.030** and **§ 17.32.040**. (Chapter 17.32)
• Variance and design review linkage: **§ 17.40.020.E**. (§ 17.40.020.E)
• Parking for ADUs / second units: **§ 17.36.035** and ADU parking exceptions in **Chapter 17.52**. (§ 17.36.035)
• Hillsborough_ZoningCode.md

• Official Hillsborough code library