Grand Terrace — Nonconforming Uses

Last reviewed: July 2, 2026

Overview

This page explains how the City of Grand Terrace treats nonconforming uses, nonconforming buildings, and nonconforming lots under the local zoning code (Title 18). The primary rules are in Chapter 18.76 and the related definitions and procedural chapters; those provisions control continuation, repair, enlargement, abandonment, and when rebuilding triggers full compliance with current zoning. See the City's zoning overview for context via the Grand Terrace zoning & planning overview and for the map of where each district applies consult Grand Terrace Zoning. Verify with the jurisdiction for parcel-specific interpretations. § 18.76.010 .

What the code says (high‑level)

• Existing lawful uses or buildings that do not meet current zone regulations may be continued, but they face limits on enlargement, change of use, and repair/reconstruction triggers. See § 18.76.020 and § 18.76.030 for continuation and permissible changes. § 18.76.031 describes abandonment/discontinuance rules. § 18.76.033 sets hard termination timeframes for various nonconforming situations. § 18.76.040 governs maintenance, repair, structural alterations and reconstruction after disaster. .

• The code defines nonconforming use and nonconforming building in the definitions chapter so you can identify what is covered. See § 18.06.565 and § 18.06.570. .

• Repairs and ordinary maintenance that do not alter the structure or exceed a monetary threshold are ministerial; larger repairs or additions generally require discretionary review (a conditional use permit) and must bring altered portions into conformance. § 18.76.040(A–C). .

• Reconstruction after damage has a value threshold: rebuilding that exceeds 75% of the pre‑damage value can trigger a requirement to bring the structure into full zoning conformity; rebuilding below that threshold may be allowed to continue nonconforming status, but buildings must meet building code and other safety requirements. See § 18.76.040(D). .

District-by-district breakdown (where nonconforming rules operate)

The nonconforming rules in Chapter 18.76 apply across the zoning districts established in Title 18. The districts are listed at § 18.09.020; below are the major districts with the district purpose, typical uses, key dimensional standards, and where they commonly apply. For permitted use lists and cross-checking whether a use is allowed in a district, consult Table 18.27.010 (nonresidential uses) and Table 18.10.030 (residential uses). § 18.09.020 .

Note: for design-level review requirements consult the City's site and architectural review procedures under Grand Terrace Design Review. For front/rear/side setback numbers and lot standards see Grand Terrace Development Standards and the residential site standards table in § 18.10.040. Also, parking rules referenced in conditional approvals come from Grand Terrace Parking. The first mention of each of those resources is linked inline above.

RH (Hillside Residential District)

• Purpose: very low density single‑family housing in constrained terrain. § 18.10.020(A).
• Typical permitted uses: single‑family homes, limited accessory uses (see Table 18.10.030).
• Key standards: minimum lot area and setbacks are set in Table 18.10.040 (the RH column). Typical rear yard and front yard rules apply; nonconforming residential structures are subject to the same repair/abandonment rules in § 18.76. § 18.10.040; § 18.76.040.
• Where it applies: hillside portions as identified on the zoning map. § 18.09.030.

R1-20, R1-10, R1-7.2 (Single‑family residential tiers)

• Purpose: varying single‑family densities (very low to standard single‑family). § 18.10.020(B–D).
• Typical uses: single‑family dwellings, accessory uses (check Table 18.10.030).
• Key standards: Table 18.10.040 shows minimum lot area (for example R1‑20 = 20,000 sf, R1‑10 = 10,000 sf, R1‑7.2 = 7,200 sf) and typical setbacks (front 25 ft, rear 35 ft in some districts; see table footnotes). § 18.10.040.
• Nonconforming notes: where an existing legal nonconforming structure sits in a required setback, limited enlargements inside that setback are permitted if they do not reduce the setback further and remain at least 5 ft from the property line; see § 18.10.040 notes and § 18.76.040.

R2, R3, R3‑S, R3‑20, R3‑24 (Multi‑family residential classifications)

• Purpose: ascending multifamily density and specialized senior housing (R3‑S) as defined in § 18.10.020(F–I).
• Typical uses: duplexes, stacked flats, apartments, senior housing (R3‑S requires a specific plan). Use permissions in Table 18.10.030.
• Key standards: Table 18.10.040 (area minima generally 12,000 sf for many R3 categories; setbacks and density ranges are listed). § 18.10.040.
• Nonconforming notes: second units / ministerial two‑unit approvals are governed by Chapter 18.65 and specific ADU/second‑unit provisions (see Grand Terrace ADUs and § 18.65.010–030), which also state that approval of an ADU shall not be conditioned on correcting unrelated nonconforming conditions. § 18.65.030(G); § 18.30.?? (ADU chapter references)

BRSP (Barton Road Specific Plan District) and GSP (Gateway Specific Plan)

• Purpose: site‑specific frameworks that set their own development standards; specific plans may supersede or supplement Title 18 for parcels within their boundaries. See § 18.14 / § 18.20 (specific plan chapters) and the specific plan descriptions in Title 18. § 18.14 / § 18.20.

AP (Administrative Professional Office)

• Purpose: professional office uses compatible with nearby residential areas. § 18.30.010.
• Typical uses: professional and administrative offices; permitted uses are listed in Table 18.27.010.
• Key standards: minimum lot area 10,000 sf, front setback 15 ft, max height 35 ft, lot coverage 100% per § 18.30.040.

C2 (General Business), CM (Commercial/Manufacturing), MR (Restricted Manufacturing), M2 (Industrial)

• Purpose: commercial and industrial intensities, each with their own site development standards and permitted/non‑permitted lists. See § 18.33.010 (C2) and Table 18.27.010; MR site development standards are in § 18.39.050. § 18.33.040; § 18.39.050.
• Typical standards (examples): C2: lot area 10,000 sf, front setback 25 ft, max height 35 ft. MR: lot area 20,000 sf, front yard 25 ft, max height 35 ft (see respective site standard tables). § 18.33.040; § 18.39.050.
• Nonconforming notes: nonconforming commercial uses may be continued but may not be expanded; changing to a use not permitted in the zone terminates nonconforming rights. § 18.76.020–032.

PUB (Public Facilities) and overlays FP (Floodplain), AG (Agricultural)

• Purpose and application: Public facilities serve city services; overlays add supplemental rules (e.g., the Floodplain Overlay contains transitional residential rules in Chapter 18.77). Overlay rules interact with nonconforming standards—see Chapter 18.77 for transitional residential uses in the FP overlay. § 18.77.010–020; § 18.09.020.

Table — Most decision‑relevant nonconforming rules

Practical guidance (plain‑English synthesis)

• If you own a property with a use or building that predates current zoning, you can usually continue it — but you cannot expand the nonconforming part, and you risk losing rights if the use stops for six months. See § 18.76.020 and § 18.76.031.

• Small repairs that only maintain the building (no structural work) are permitted; larger repairs or additions that change floor area or structural systems typically require a conditional use permit and must bring the altered parts into compliance. See § 18.76.040(A–C).

• After fire, earthquake or other casualty, rebuilding is allowed to the prior condition if rebuilding costs are less than 75% of pre‑damage value; if rebuilding costs exceed 75%, the project may be required to meet current zoning and go through site/architectural review. § 18.76.040(D).

• If you are proposing an ADU, the City’s ADU rules explicitly state that the approval cannot be conditioned on correcting unrelated nonconforming conditions on the property. See Chapter 18.65 and the ADU provisions. § 18.65.030; see also the accessory dwelling unit provisions.

• For design and neighborhood impacts, expect site and architectural review where required (see Grand Terrace Design Review, Chapter 18.63). § 18.63.010–040.

Checklist — what an applicant must satisfy when working with a nonconforming use or structure

• Determine whether the property is a nonconforming use or nonconforming building (see definitions § 18.06.565, § 18.06.570).
• Document continuous operation and the exact area occupied by the nonconforming use at the adoption date (to establish limits on enlargement) — § 18.76.020.
• If changing the use or extending a nonconforming portion, prepare a use permit application — § 18.76.030(B–C).
• If proposed repairs/alterations exceed 25% of assessed value in a year or include structural work, apply for a conditional use permit and bring altered parts into conformity — § 18.76.040(B–C).
• If the building was damaged, provide cost estimates/appraisal to verify the 75% reconstruction threshold; if above 75% plan for zoning conformance and site/architectural review — § 18.76.040(D).
• If the use has been inactive for approaching 6 months, confirm whether abandonment has occurred and seek Planning Director guidance — § 18.76.031.
• File building permits and obtain business license after approvals; see building permit/business license process § 18.83.070.

Risks & Ambiguities

Plain-English Summary

If you have a use or building in Grand Terrace that doesn't match current zoning, you can usually keep operating it, but you generally cannot expand it or switch it to a different, unpermitted use; long inactivity (six months) or large repairs/rebuilds (see the 25% repair rule and the 75% reconstruction trigger) will force you to comply with current zoning or lose the nonconforming status. § 18.76.020–040.

Source References

• Grand Terrace Municipal Code — Chapter 18.76 Nonconforming Uses and Buildings (general purpose, continuation, abandonment, repair, reconstruction): § 18.76.010–050.
• Grand Terrace Municipal Code — Termination/limitation timelines for nonconforming operations: § 18.76.033.
• Grand Terrace Municipal Code — Definitions: § 18.06.565 (Nonconforming building), § 18.06.570 (Nonconforming use).
• Grand Terrace Municipal Code — Repair and reconstruction after casualty (75% threshold): § 18.76.040(D).
• Grand Terrace Municipal Code — Zoning districts list and map adoption: § 18.09.020.
• Grand Terrace Municipal Code — Residential site development standards (Table 18.10.040) and use/density descriptions: § 18.10.040 and § 18.10.020.
• Grand Terrace Municipal Code — Nonresidential use table 18.27.010 (permitted/conditional uses).
• Grand Terrace Municipal Code — MR district site standards § 18.39.050.
• Grand Terrace Municipal Code — AP district standards § 18.30.040.
• Grand Terrace Municipal Code — Site & architectural review (design review): Chapter 18.63.
• Grand Terrace Municipal Code — Second units / ministerial two‑unit rules (ADUs/second units): Chapter 18.65.

For the City’s web overview pages referenced above (zoning, development standards, parking, design review, overlay districts, ADUs, and the state building code), use the City menu links provided in your local planning portal: Grand Terrace zoning & planning overview, Grand Terrace Zoning, Grand Terrace Land Use, Grand Terrace Development Standards, Grand Terrace Parking, Grand Terrace Design Review, Grand Terrace Overlay Districts, Grand Terrace ADUs, and California Building Standards Code.

Retrieved passages

• CBC § 1 (§ 1) High relevance show source text
• Grand Terrace Zoning Code (§ 5) High relevance show source text
• CBC § 1 (§ 1) High relevance show source text
• Grand Terrace Zoning Code (§ 2) High relevance show source text
• Grand Terrace Zoning Code (§ 1) High relevance show source text
• Grand Terrace Zoning Code (section is) Medium relevance show source text
• CBC § 200 (Title or) Medium relevance show source text
• Grand Terrace Zoning Code (§ 8) Medium relevance show source text
• Grand Terrace Zoning Code (§ 66314) Medium relevance show source text
• Grand Terrace Zoning Code (§ 66333) Medium relevance show source text
• CBC § 66321 (§ 66321) Medium relevance show source text
• Grand Terrace Zoning Code (Section 18.84.50) Medium relevance show source text
• Grand Terrace Zoning Code (section 21064.3) Medium relevance show source text
• Grand Terrace Zoning Code (Chapter 18.63) Medium relevance show source text
• Grand Terrace Zoning Code (§ 10) Medium relevance show source text
• Grand Terrace Zoning Code (Chapter 18.03) Medium relevance show source text
• Grand Terrace Zoning Code (§ 4) Medium relevance show source text
• Grand Terrace Zoning Code Medium relevance show source text
• CBC § 66314 (§ 66314) Medium relevance show source text
• Grand Terrace Zoning Code Medium relevance show source text
• Grand Terrace Zoning Code Medium relevance show source text
• California Fire Code Medium relevance show source text
• Grand Terrace Zoning Code (§ 2) Medium relevance show source text
• Grand Terrace Zoning Code (§ 6) Medium relevance show source text

Cited sections

• Grand Terrace Municipal Code — Chapter **18.76** Nonconforming Uses and Buildings (general purpose, continuation, abandonment, repair, reconstruction): **§ 18.76.010–050**. (§ 18.76.010)
• Grand Terrace Municipal Code — Termination/limitation timelines for nonconforming operations: **§ 18.76.033**. (§ 18.76.033)
• Grand Terrace Municipal Code — Definitions: **§ 18.06.565** (Nonconforming building), **§ 18.06.570** (Nonconforming use). (§ 18.06.565)
• Grand Terrace Municipal Code — Repair and reconstruction after casualty (75% threshold): **§ 18.76.040(D)**. (§ 18.76.040)
• Grand Terrace Municipal Code — Zoning districts list and map adoption: **§ 18.09.020**. (§ 18.09.020)
• Grand Terrace Municipal Code — Residential site development standards (Table **18.10.040**) and use/density descriptions: **§ 18.10.040** and **§ 18.10.020**. (§ 18.10.040)
• Grand Terrace Municipal Code — Nonresidential use table **18.27.010** (permitted/conditional uses).
• Grand Terrace Municipal Code — MR district site standards **§ 18.39.050**. (§ 18.39.050)
• Grand Terrace Municipal Code — AP district standards **§ 18.30.040**. (§ 18.30.040)
• Grand Terrace Municipal Code — Site & architectural review (design review): **Chapter 18.63**. (Chapter 18.63)
• Grand Terrace Municipal Code — Second units / ministerial two‑unit rules (ADUs/second units): **Chapter 18.65**. (Chapter 18.65)
• GrandTerrace_ZoningCode.md

• Official Grand Terrace code library