Removing vents causes other problems. They are there for a reason. They remove moisture, prevent mold, regulate temperature, lower energy costs, prevent roof damage.
They have vents that do not allow or restrict ember entry and vents that seal shut when it gets hot.
Even with Hardy board and other resistant materials, the underlay material can get hot enough to burn. Our neighbor’s house was metal clad and it burned.
Trees usually aren’t a huge problem as long as tree liter is removed, and there aren’t any ladder fuels. That may be a big if. Crown fires are rare, that is where the fire advances via tree top without any aid from the ground fuels.
Paradise just had too much vegetation period, but yes, the less the vegetation the better.
Still, we see many stand alone structures, Ralph’s grocery in Palusade, BOA in Palisades , K-Mart in Santa Rosa, fast food restaurants with little around them in the middle of a parking lot burn.
There are many variables, but that doesn’t mean you don’t do what you can.
There was a fire on Laguna Beach in 1993 that burned a whole hillside going down towards the beach. When the fire was done there was ONE house remaining on the hill right in the middle. Every other house around it had burned to the foundation.
The house was relatively new. It DID NOT have soffit vents. It had a special kind of roof vents. Its sidewalls and roof were made out of fireproof/resistant materials. There was an article all about how this house had survived while all the others were destroyed.
I just found an article about it:
I BELIEVE this is the same house:
https://www.latimes.com/archives/la-xpm-1993-11-06-hm-53777-story.html
Here are the key construction elements:
A. Eaves: Narrow eaves between the roof and exterior walls are sealed with stucco. There are no ventilator panels in the eaves, so flames could not get in from underneath.
B. Roof: Non-flammable concrete roof tiles are nailed down, so they won’t not rip off in high winds.
C. Roof ventilators: Air comes into the attic crawl space through vents at the front and rear of the house and leaves through vents on the top of the roof.
D. Decks: Bottoms of decks are finished with stucco.
E. Side porch: Firefighters were able to stand on the side porch to fight flames from the next-door house, only 14 feet away.
F. Lower windows: On the lower level of the house, five small windows are set in a foot-thick concrete wall. This helped keep out heat from surrounding burning houses.
G. Walls: Exterior: One-inch thick stucco siding; no exposed wood. Lower-level walls are one-foot thick concrete.
Sorry, I left off these two last parts:
H. Windows and skylights: Double-paned windows helped keep heat out. The outer panes on two windows broke, but the inner panes continued to protect the home. Two overhead skylights imported from Germany are made of double-paned glass. Conventional plastic skylights would have melted, allowing embers to fall into the home.
I. Landscaping: The yard is kept clean of dry brush and weeds. No tall, dry trees are near the house. Much of the landscaping is done in water-retaining plants; ice-plant under the rear decks helped keep the fire at bay.
“Removing vents causes other problems.”
You still have a POWER vent at the peak of the roof. You eliminate continuous soffit vents.
IF all the items in this article were made part of the building codes in these fire prone areas there would be a lot less loss of structures.