Wildfire season has a way of sneaking up on coastal-hills communities. If you own or plan to own a home along San Mateo County’s ridges and coast, creating defensible space is one of the most practical ways to protect your investment. You want clear, local guidance that fits our terrain and rules, not a generic checklist. This guide shows you exactly how to build defensible space from 0 to 100 feet, what the county expects, and where to find help nearby. Let’s dive in.

Why defensible space matters in San Mateo County

San Mateo County’s hills and coast include grasslands, oak woodlands, coastal scrub and some eucalyptus stands, which can feed fast-moving fire on slopes. Coastal weather helps at times, but it does not remove wildfire risk during dry, windy periods. The 2020 CZU Lightning Complex burned across San Mateo and Santa Cruz counties and forced major evacuations, a reminder that fires can move quickly in our area (read the incident overview).

Creating defensible space reduces flame lengths near the home and cuts off ember ignition sources. Paired with simple home-hardening upgrades, it can materially raise a home’s chance of surviving a wildfire, according to recent reporting that summarizes research on combined measures (see the research summary).

Know the rules before you clear

California’s Public Resources Code 4291 requires you to manage vegetation up to 100 feet from structures, or to your property line if it is closer. CAL FIRE outlines the defensible space zones and spacing practices you are expected to follow (review the state guidance). The state is also advancing an ember-resistant standard for the first 5 feet around structures, often called Zone 0, under Board of Forestry rulemaking (track the Zone 0 program).

San Mateo County Fire conducts defensible space inspections and posts preparedness resources, including how to schedule an inspection and evacuation tools. If you live in an incorporated city, also check your city fire department for any stricter rules (start with the County’s preparedness page).

Build your defensible space by zone

Zone 0: 0–5 feet from structures

• Replace wood or bark mulch with gravel, pavers or concrete in the first 5 feet.
• Remove all dead plants and leaf litter. Keep roofs, gutters and eaves clean.
• Move firewood, spare lumber and propane or BBQs out of this zone, or set them on noncombustible pads farther out.
• Install ember-resistant vents and consider metal gutter covers. Seal gaps larger than 1/8 inch.

Zone 1: 5–30 feet

• Keep this area lean, clean and green. Remove dead material, prune regularly and irrigate plants as needed.
• Break up fuel ladders. Maintain space between shrubs, and prune tree canopies so lower branches are at least 6 feet above ground.
• Store woodpiles at least 30 feet from structures and maintain 10 feet of clearance around them on bare soil.

Zone 2: 30–100 feet (or to your property line)

• Mow annual grasses to 4 inches or less and limit leaf litter to a light layer.
• Increase horizontal spacing between shrubs and trees, especially on steeper slopes.
• Remove ladder fuels under trees to reduce flame heights before they reach canopies.

Harden your home to stop embers

A few upgrades can block the most common ignition paths. Fire Safe San Mateo offers clear homeowner guidance you can use to prioritize work (browse the home-hardening tips). Focus on:

• Class A roof materials in good condition.
• Ember-resistant vents and well-sealed eaves and soffits.
• Screened or covered gutters kept free of debris.
• Dual-pane or tempered glass windows where feasible.
• Noncombustible or enclosed decks. Avoid wood fences that attach directly to the house.
• Maintain 10 feet of bare soil around LPG tanks and outbuildings.

Plant choices that fit hills and coast

Choose low-fuel, high-moisture plants with open branching. Avoid high-oil species close to the house, including large junipers, many conifers and eucalyptus. Keep everything pruned and spaced to prevent fuel ladders. For plant ideas and simple yard design principles, use this local overview of firewise landscaping from UC Master Gardeners (see firewise landscaping steps).

Local help, inspections and debris removal

• Inspections and alerts. San Mateo County Fire posts defensible space requirements, inspection info and evacuation tools like SMC Alert and Zonehaven. You can request an inspection and get a checklist of required actions (visit County preparedness).
• Chipping and disposal. The San Mateo Resource Conservation District runs a Neighborhood Chipper Program that helps selected areas turn cleared brush into chips at no cost (check the Chipper Program).
• Permits and protected areas. If you plan major tree removals or work in the coastal zone or near sensitive habitats, contact County Planning or the RCD first. The RCD’s Forest Health and Fire Resilience program explains when permits may be needed and how their Public Works Plan can streamline coastal projects (learn about RCD’s permitting support).

Quick seller and buyer checklist

• Confirm your jurisdiction, then schedule a defensible space inspection.
• Start with Zone 0, then work out to 30 and 100 feet.
• Document the work you complete. Photos and receipts help with inspections and disclosure.
• Tackle key home-hardening items next, starting with vents, gutters and roof condition.
• Use licensed contractors for tree work. Ask about erosion control on steep slopes.

When you prepare early, defensible space work is manageable and cost effective. It also makes your property easier to maintain, shows care to future buyers and aligns with local expectations. If you want a second set of eyes as you plan improvements or get your home market ready, the family-led team at Dapkus Real Estate Team is here to help you move forward with confidence.

FAQs

What is defensible space and how far should I clear?

• California expects you to manage vegetation up to 100 feet from structures, or to the property line, with the most intensive work in the first 30 feet (CAL FIRE guidance).

What is Zone 0 in San Mateo County?

• Zone 0 is the ember-resistant area within 0–5 feet of structures; the state is finalizing standards for this zone through the Board of Forestry (Zone 0 rulemaking).

Do I need a permit to remove trees near the coast?

• You might; removals and work in the coastal zone or sensitive habitats can trigger permits, so contact County Planning or the RCD before major clearing (RCD permitting overview).

How can I dispose of brush after clearing?

• Look for the San Mateo RCD Neighborhood Chipper Program, which offers no-cost chipping in selected neighborhoods by schedule (program details).

Does defensible space guarantee a home will survive a wildfire?

• No single step can guarantee survival, yet defensible space plus home hardening significantly improves the odds compared to doing nothing (research summary).