Most homes are not lost to a wall of flame. They are lost to a single ember finding a vent, an eave, or the space under a deck.
The image most people carry of a house burning is a wall of flame arriving from the canyon. It happens, but it is not what takes most homes. Far more are lost to embers — small burning fragments carried on wind, sometimes more than a mile ahead of the fire, landing by the thousand and finding whatever opening a house offers them.
That distinction changes everything about how you build. A house designed to resist radiant heat and a house designed to resist ember intrusion are different buildings, and the second is what actually survives.
This is the construction side of a rebuild. If you are earlier than that, our step-by-step rebuild guide covers the whole sequence, and how long a fire rebuild actually takes covers the schedule.
The Roof Comes First
It is the largest horizontal surface you own and the first thing embers land on. A Class A roof assembly is the baseline, and worth understanding as an assembly rather than a product: the covering, the underlayment, and the deck perform together.
The vulnerable points are not the field of the roof but its edges and transitions. Valleys collect debris, and dry debris is fuel sitting on your roof. The roof-to-wall intersection, where a lower roof meets an upper wall, is a place embers gather and heat concentrates. Ridge and eave venting are direct paths into the attic. Detail those carefully and the roof does its job.
Vents Are the Way In
Your house needs to breathe — attic and crawlspace ventilation is a building requirement, not an optional feature. Every one of those openings is also an invitation. An ember entering an attic lands in insulation and stored belongings, in a space nobody will see burning until it is well established.
Ember-resistant venting is designed to resist that, using fine baffled paths or intumescent materials that close under heat. Ordinary quarter-inch screen does not qualify and has not for some time.
This is among the least expensive protections available and among the most effective. If you do nothing else to an existing home, do this.
Walls, Eaves, and Soffits
Non-combustible or ignition-resistant cladding is the requirement — stucco, fiber cement, masonry, metal, or treated assemblies that carry the appropriate rating.
Eaves deserve particular attention. Open eaves create a pocket where rising heat and embers get trapped against combustible framing, and they are a known failure point. Enclosing and protecting the soffit removes it. It is a modest detail that decides outcomes.
One note on design: fire-resistant does not mean visually cold. Steel, stone, plaster, fiber cement, and rated glazing produce warm and beautiful houses. The constraint is real but it is not aesthetic, and we would resist any suggestion that you must choose between a home that looks the way you want and one built to survive.
Most homes are not lost to flame arriving at the wall. They are lost to a single ember finding a vent, an eave, or a gap under a deck.
Windows
Glass fails from heat before the wall around it does, and once a window breaks the fire has an opening into the room. Tempered glass resists thermal stress substantially better than annealed, and multi-pane assemblies add protection because the outer layer shields the inner.
Frames matter too — metal and fiberglass frames outperform vinyl, which distorts at temperatures glass survives.
On a house with large glazed openings, which most Westside homes have and should have, this is a significant cost line. It is also directly protective, and it is not a place to economize.
Decks and the First Five Feet
The zone immediately around the structure does more to determine survival than anything further out, and it is the area homeowners most often decorate rather than defend.
Within roughly five feet of the walls, the goal is nothing that will carry fire to the house: no bark mulch, no dense foundation shrubs, no firewood stacked against siding, no combustible fencing meeting the wall. Hardscape, gravel, well-irrigated low plantings, and clear space instead.
Decks are the frequent failure. An elevated deck creates a sheltered space underneath where embers accumulate out of the wind and out of sight. Ignition-resistant decking, enclosure of the underside, and keeping that space genuinely clear are what address it.
Attached fencing deserves a mention. A wood fence running to the house is a fuse. Use non-combustible material for at least the final several feet where it meets the structure.
Sprinklers, Water, and Power
Interior sprinklers are required in new construction and address fire inside the home. They are not a wildfire defense and should not be counted as one.
For homes in higher-exposure locations, exterior water is worth discussing during design — dedicated storage, a pump that operates without grid power, and exterior coverage at vulnerable elevations. These are meaningful investments and they are only sensible if they can run when the power is out, which during a wildfire it generally is. That means a generator or battery system sized for the pump, planned in.
Walking neighborhoods after a fire teaches more than any specification sheet. On one street the homes that came through were not the newest or the most expensive. They were the ones with enclosed eaves, ember-resistant vents, clear space in the first five feet, and no wood fence running to the wall. Ordinary details, correctly done, repeatedly.
How to Think About the Investment
On a new build or rebuild, wildfire-resistant construction commonly adds six to twelve percent to hard cost. Much of it is now required rather than optional, so the real question is where to go beyond the minimum.
For what the base number looks like before any of this is added, we broke down current figures in what a fire rebuild actually costs in Pacific Palisades, and the gap between a settlement and a real budget in your insurance settlement vs. your real rebuild budget.
Ranked by protection per dollar, we would prioritize in this order:
- Ember-resistant venting. The cheapest meaningful protection there is.
- Enclosed and protected eaves. Removes a known failure point for very little money.
- The first five feet of landscape. Costs almost nothing and is entirely within your control.
- The roof assembly and its transitions. Valleys, roof-to-wall intersections, and venting details.
- Upgraded glazing. Expensive, but directly protective on a house with large openings.
- Deck materials and enclosure. Matters most where the deck is elevated.
Everything on that list is far cheaper to build in than to add later. A vent specified during design costs almost nothing; retrofitting every vent on a finished house is a project. That is the argument for settling these questions during design development rather than treating them as a specification detail near the end.
Much of what is described here is now code rather than choice. We went through which requirements changed, and what they do to a footprint and a budget, in what changed in the building code since the house you lost.
