Home Assessment Tips
What is the Home Ignition Zone?
The home ignition zone (HIZ) consists of your house and its immediate surroundings. Managing your HIZ is critical to reducing wildfire risk. Each of the three home ignition zones has a different purpose. Therefore, we must manage the fuel loads accordingly to reduce the risk of ember ignition, radiant heat, and direct flame.
Credit source: NFPA
Immediate Area or Zone 0 (0-5 feet): The first 5 feet adjacent to your house is the most critical area and should be cleared of any and all combustible vegetation or materials. Start mitigation efforts at the home itself, then move outward.
Roofs and Gutters: Clean roofs, gutters, and roof valleys of all debris (leaves, pine needles, etc.). Repair or replace any loose or missing shingles or tiles to prevent ember entry.
Vents and Openings: Install 1/8-inch metal mesh screening on all attic, foundation, and eave vents to block embers. Check and repair any damaged or loose window screens and broken windows.
Decks and Patios: Screen in areas below decks and patios to prevent the accumulation of debris and flammable materials. Do not store anything combustible underneath them.
Immediate Home Perimeter: Remove any flammable materials from the area directly next to the house walls. This includes combustible mulch, dry plants, leaves, and firewood piles.
Gaps and Cracks: Seal any gaps or cracks in the exterior of your home, including the roof assembly, to prevent embers from getting inside.
Intermediate Zone or Zone 1 (5-30 feet): Employ firewise landscaping and hardscaping techniques to create breaks that slow a fire's spread by increasing the space between plants, trees, and your home.
Reduce Ground Fuels: Keep grasses mowed to four inches or less, and clear all vegetation from underneath large propane tanks.
Break Up Vegetation: Create fuel breaks using driveways, paths, patios, and decks to slow a fire's spread. Limit trees and shrubs to small clusters to prevent a continuous path for fire.
Eliminate Ladder Fuels: Prune trees to a height of six to ten feet from the ground to prevent a surface fire from climbing into the crowns. For shorter trees, don't prune more than one-third of the total height.
Space Out Trees: Ensure there is at least ten feet of space between mature tree canopies and any structures. Maintain a minimum of eighteen feet between tree crowns, increasing that distance on sloped terrain.*
Strategic Tree Placement: Plan the placement of new trees so their mature canopies will be no closer than ten feet to the edge of your home or other structures.
Credit source: NFPA
Example of ladder fuels
Extended Zone or Zone 2 (30-100+ feet): The goal here is not to eliminate fire, but instead, to reduce dense vegetation to interrupt fire’s path and keep flames smaller and on the ground.
Clear Out Dead Material: Remove dead plants, trees, and heavy accumulations of leaves or pine needles from your yard.
Separate Trees: Remove any small conifers or other vegetation growing between mature trees to prevent fire from spreading between them.
Protect Outbuildings: Clear all vegetation away from sheds, storage buildings, and other structures on your property.
Trees 30 to 60 feet from the home should have at least 12 feet between canopy tops.*
Trees 60 to 100 feet from the home should have at least 6 feet between the canopy tops.*
*The distances listed for crown spacing are suggested based on NFPA 1144. However, the crown spacing needed to reduce/prevent crown fire potential could be significantly greater due to slope, the species of trees involved and other site specific conditions. Check with your local forestry professional to get advice on what is appropriate for your property.
What is a Hardened Home?
Construction materials and the quality of the defensible space surrounding it are what give a home the best chance to survive a wildland fire. Embers from a wildland fire will find the weak link in your home’s fire protection scheme and gain the upper hand because of a small, overlooked or seemingly inconsequential factor. However, there are measures you can take to safeguard your home from wildland fire. While you may not be able to accomplish all the measures listed below, each will increase your home’s, and possibly your family’s, safety and survival during a wildland fire.
ROOFS
Roofs are the most vulnerable surface where embers land because they can lodge and start a fire. Roof valleys, open ends of barrel tiles, and rain gutters are all points of entry.
EAVES
Embers can gather under open eaves and ignite exposed wood or other combustible material.
VENTS
Embers can enter the attic or other concealed spaces and ignite combustible materials. Vents in eaves and cornices are particularly vulnerable, as are any unscreened vents.
WALLS and FENCING
Combustible siding or other combustible or overlapping materials provide surfaces or crevices for embers to nestle and ignite. Combustible fencing can become engulfed and if attached to the home’s sidings can carry the fire right to the home.
WINDOWS and DOORS
Embers can enter gaps in doors, including garage doors. Plants or combustible storage near windows can be ignited from embers and generate heat that can break windows and/ or melt combustible frames
BALCONIES and DECKS
Embers can collect in or on combustible surfaces or the undersides of decks, lanai, and balconies, ignite the material, and enter the home through walls or windows. Post-and-pier homes, common throughout Hawaiʻi, are especially vulnerable since most of the underside of the house is exposed.
To harden your home even further, consider protecting your home with a residential fire sprinkler system. In addition to extinguishing a fire started by an ember that enters your home, it also protects you and your family year-round from any fire that may start inside your home.
Watch Out for Exotic Vegetation
Non-native trees, such as ironwood (pictured right), constantly drop needles, leaves, branches, and other debris, so it’s best to stay on top of removing them from the ground before the pile becomes a major project. Consider reforesting these areas with native trees that don’t drop large amounts of debris.
Invasive grasses such as guinea and fountain grass grow rapidly when unmanaged and can dry out very quickly, creating a major fire hazard. Weed them often and consider replanting with low-lying, drought-tolerant, native ground cover.
Xeriscaping - Hawaiʻi Style
Creating a wildfire-resilient home does not necessarily mean eliminating the presence of greenery on your property. You can still landscape around your home to make it fire-safe without compromising beauty and aesthetics. By planting native, drought-tolerant plants (xeriscaping) around your home, you can:
Protect your home from wildland fire ignition and spread
Beautify your property with native plants
Decrease the maintenance needs of your landscaping
Mālama ʻĀina by perpetuating important natural and cultural resources
For the drier areas of Hawaiʻi, consider that native dryland plants are specially adapted to local conditions and require less upkeep, water, and fire maintenance, saving you a great deal of time, money, and resources. Non-native, lush plants often drop hazardous debris and can become fire-prone in drought conditions.
Tips for Firewise Landscaping (Planting Pono)
Right Tree
Tree Selection: Choose the right plants and trees for your yard.
The right trees can help buffer against a fire rather than being fire hazards.
Fires are fueled by dried grasses, woody debris, and dried leaves.
Use native and canoe plants that are specially adapted to local conditions and require less water to keep green.
When planting a seedling, ensure it has space to mature and grow.
Avoid invasive fire-promoting plants and trees like paperbark tea tree, Formosan koa, Podocarpus, and lantana.
Check out the Hawaiʻi Pacific Weed Fire Risk Assessment to determine which plants to exclude or remove from your yard. Go Native Plants, Plant Pono & Pacific Islands SelecTree can help you find the best trees for your yard and conditions. These three articles may also help you make great choices: Coastal Plants for Creating Green Breaks, Top 10 Fire-Resistant Plants for Hawaiʻi, and Canoe Plants (Nā Mea Kanu Waʻa).
Right Place
Site selection: Choose the right place for trees in your yard.
Allow for space between the tree canopy and your home. Branches should not touch the home.
Create a “fire-free” area within 5 feet of your home using gravel, cinder, etc., or well-hydrated plants.
Keep maximum distance between tree clusters/canopies to reduce the risk of wildfire spreading between vegetation.
Right Care
Regularly remove dried grasses, woody debris, and dried leaves.
Regularly trim branches away from your home and other trees.
Pruning to allow light and air between branches can promote tree health and resilience to pests.
Keep plants and trees well-hydrated and healthy. Native and drought-resistant plants tend to require less water and upkeep.
ROOF
Firewise recommendations for roofs focus on using the highest-rated materials, maintaining the roof and gutters to be free of debris, and sealing all potential entry points for wind-blown embers. The roof is one of the most vulnerable parts of a home during a wildfire because embers can travel for miles and ignite flammable roofing material.
Roofing materials
Select a roof with a Class A fire rating, the most fire-resistant classification. Class A roofs are effective against severe fire exposure and limit flame spread.
Build your roof or re-roof with fire-resistant materials. Here are the most effective Class A roofing materials:
Clay or concrete tiles: Naturally non-combustible and highly fire-resistant, though heavier than other materials.
Metal: Non-combustible materials such as aluminum, steel, or copper do not ignite when exposed to direct flame or embers.
Slate: A naturally fire-resistant stone that offers premium protection, though it is heavy and more expensive.
Fiberglass asphalt shingles: A popular, cost-effective option that features a fire-resistant core. Most asphalt shingles available have a Class A rating.
Synthetic composite shingles: Products designed to mimic the appearance of other materials, like wood, while providing enhanced fire resistance.
Roof structure
Fire-resistant underlayment: If installing a new roof, include a fire-resistant underlayment to add a critical layer of protection beneath the outer material.
Ongoing maintenance
Clean regularly: Keep roofs, gutters, and downspouts free of dead leaves, pine needles, and other flammable debris.
Remove overhanging branches: Prune tree limbs within 10 feet of your roof to reduce the risk of ignition from direct flame exposure.
Repair gaps: Replace or repair any loose or missing shingles or tiles to prevent embers from penetrating the roof covering. Block any spaces between the roof decking and covering to prevent ember intrusion.
CHIMNEY
Cover your chimney and stovepipe outlets with a non-flammable screen of 1/4-inch wire mesh or smaller to prevent embers from escaping and igniting a fire.
Make sure that your chimney is at least 10 feet away from any tree branches.
SOLAR PANELS
The buildup of debris under solar panels can ignite and lead to roof ignition. Routinely clean under solar panels, and consider using a non-flammable screen of 1/8-inch wire mesh or smaller to prevent flammable build-up from accumulating.
SKYLIGHTS
The buildup of debris on skylights can ignite and lead to roof ignition. Routinely clean skylights to prevent flammable build-up from accumulating and check the seal to ensure embers cannot enter in the case of a wildfire.
Consider replacing if the skylight is single-pane, non-tempered glass.
VENTS
Vents on homes are particularly vulnerable to flying embers.
All vent openings should be covered with 1/8-inch or smaller metal mesh. Do not use fiberglass or plastic mesh because they can melt and burn. DO NOT install vents on dryer outlets.
Attic vents in eaves or cornices should be baffled or otherwise protected to prevent ember intrusion (mesh is not enough).
NON-COMBUSTIBLE ENCLOSED EAVES
Box in eaves: Enclosing open eaves and soffits with fire-resistant materials, like metal or non-combustible wood, prevents embers from collecting and entering the attic.
If this retrofit is not feasible, consider filling all gaps and cracks in the eaves with fireproof caulking or sealant. Pay particular attention to the areas where the rafters meet the roof assembly.
RAINGUTTERS
Routinely clean gutters to prevent flammable buildup from accumulating. Screen or enclose rain gutters with 1/8-inch or smaller metal mesh to prevent the accumulation of plant or other flammable debris.
Consider replacing vinyl gutters with metal gutters (steel, aluminum, copper, or similar) if possible to prevent vinyl gutters from catching fire or melting during a wildfire event.
Firewise guidelines emphasize using non-combustible materials for gutters and covering them with metal guards to prevent the accumulation of flammable debris.
WALLS
Wood products, such as boards, panels, or shingles, are common siding materials. However, they are combustible and not good choices for fire-prone areas.
Build or remodel with fire-resistant building materials, such as plaster, cement, masonry, or stucco.
Be sure to extend materials from the foundation to the roof.
For Firewise standards, there should be a minimum 6-inch vertical clearance between combustible siding and the ground or any attached horizontal surface. This clearance must be filled with a non-combustible material to prevent embers from igniting the wall.
WINDOWS
Heat from a wildland fire can cause windows to break even before the home ignites. It allows burning embers to enter and start internal fires. Single-pane and large windows are particularly vulnerable.
For Firewise standards, choose tempered, dual-pane glass in smaller sizes and metal frames. Also, add 1/16-inch metal mesh screens to prevent ember entry and fire-rated shutters that are specifically designed to act as a barrier against fire and smoke for added protection.
Limit the number and size of windows, especially those facing large vegetation areas, and use fire-resistant reflective films for extra defense against radiant heat.
DECK or PATIO COVER
Use heavy timber or non-flammable construction material for decks.
Enclose the underside of balconies and decks with fire-resistant materials to prevent embers from blowing underneath.
Keep your deck clear of combustible items, such as baskets, dried flower arrangements, and other debris.
The decking surface must be ignition-resistant if it’s within 10 feet of the home.
INSIDE
Keep working fire extinguishers on hand.
Install smoke alarms on each level of your home and near bedrooms. Test them monthly and change the batteries twice a year.
NON-COMBUSTIBLE FENCING
Make sure to use noncombustible fencing to protect your home during a wildland fire.
If your fence is made of combustible materials (e.g., wood or vinyl) and attaches to your home or structure, consider replacing the last 5 feet (minimum) of the fence with non-combustible materials (e.g., metal or stone) to prevent a “wicking effect” of flame to the home or structure if the fence catches fire.
For similar reasons, a wooden gate attached to the home or structure should be left open when wildfire is nearby.
ADDRESS
Make sure your address is clearly visible from the road (install lighting for night visibility); preferably install reflective address signs with 4" tall, 1/2" wide numbers.
GARAGE
Have a fire extinguisher and tools such as a shovel, rake, bucket, and hoe available for fire emergencies.
Install a seal kit around the garage door to prevent ember intrusion into the garage space.
Install a solid door with self-closing hinges between the living areas and the garage. Install weather stripping around and under this door to prevent ember intrusion.
Store all combustibles and flammable liquids away from ignition sources.
WATER SUPPLY
Have multiple garden hoses that are long enough to reach any area of your home and other structures on your property.
If you have a pool or well, consider a pump.
If your catchment tank is designated for firewater storage, contact your local fire department to confirm that the connections meet their specifications. This ensures fire suppression responders have the proper hookups for emergency use.
HOME SITE and YARD
Ensure you have at least a 100-foot radius of thinned, well-maintained, or cleared vegetation around your home. Note that even more clearance may be needed for homes in severe hazard areas. This means looking past what you own to determine the impact a common slope or neighbors’ yard will have on your property during a wildland fire.
Cut dry weeds and grass before noon when temperatures are cooler to reduce the chance of sparking a fire.
Landscape with fire-resistant plants that have a high moisture content and are low-growing.
Keep woodpiles, propane tanks, and combustible materials away from your home and other structures such as garages, barns, and sheds.
Ensure that trees are far away from power lines.
DRIVEWAYS and ACCESS ROADS
Driveways should be designed to allow fire and emergency vehicles and equipment to reach your house.
Minimum road width: At least 20 feet of unobstructed width. Exception for single-family homes: The width can be reduced to a minimum of 15 feet if an area at least 20 feet wide is provided within 150 feet of the home.
Vertical clearance: Trim trees and shrubs overhanging the road to a minimum of 13-1/2 feet to allow emergency vehicles to pass.
Dead-end roads: For roads exceeding 150 feet in length, an approved turnaround must be provided. For single-family homes, a turnaround is required if the dead-end road is longer than 250 feet.
Ensure that all gates open inward and are wide enough to accommodate emergency equipment.
Local rules should be checked for variations, as individual counties may adopt amendments to the state fire code.
BACKUP POWER and GENERATORS
Hawaiian Electric has adopted the Public Safety Power Shutoff (PSPS) program to help prevent wildfires during certain conditions, such as hot, windy weather in areas where dry vegetation surrounds electrical equipment.
Prepare for power outages before wildfires and other emergencies. We recommend having:
Battery-powered AM/FM/weather radio
Some models can be charged via built-in solar panels or hand cranks for continued use during power outages.
NOAA Weather Radio broadcasts National Weather Service warnings, watches, forecasts, and other hazard information all day. The radio program broadcasts on frequencies 162.400 (channel 1), 162.450 (channel 3), 162.500 (channel 6), and 162.550 (channel 7) in the Hawaiian Islands.
2. Battery-powered lanterns or flashlights
Some models can be charged via built-in solar panels or are disposable battery-dependent; in that case, be sure to have a stockpile of D, C, AA, AAA, and 9-volt batteries.
Other backup power sources may include the following:
Battery-powered or portable cell phone chargers
Portable Power Stations
Power Walls, such as Tesla batteries
Battery backups for garage door openers
Generators