Building Permits in La Crescenta-Montrose, CA

A small accessory concrete slab (walkway, patio pad, small equipment pad) of 200 square feet or less at grade is exempt from a building permit. Larger slabs that will support a future structure or are part of a building foundation fall under the building permit. Stormwater BMPs may apply per CALGreen and LA County LID ordinance for impervious surfaces over a threshold.

A freestanding deck not more than 30 inches above grade and not more than 200 square feet is exempt from a building permit under 2025 CRC R105.2. County zoning setbacks still apply. VHFHSZ parcels (most of La Crescenta-Montrose near Angeles National Forest): Chapter 7A ignition-resistant materials may still apply to deck materials and surrounding 5-ft ember zone.

Fences 7 feet or less are exempt from a building permit under 2025 CRC R105.2. County zoning regulates fence height (typically 3.5 feet front-yard, 6 feet rear/side per LA County Title 22). VHFHSZ defensible space rules under PRC 4291 + AB 3074 may restrict combustible fences within 5 feet of structures (use non-combustible material in ember zone).

An at-grade uncovered concrete or paver patio is exempt from a building permit. Adding a cover, roof, or screen enclosure turns the covered area into an accessory structure requiring a building permit. CALGreen and county zoning may regulate impervious surface coverage and stormwater runoff.

A retaining wall 4 feet or less measured from bottom of footing to top of wall, without surcharge, is exempt from a building permit under 2025 CRC R105.2. Drainage and erosion control remain the owner's responsibility. Seismic zone (SDC D near Sierra Madre fault) and La Crescenta's hillside terrain require careful drainage design.