---
title: every mitigation strategy has two halves
canonical_url: https://ensurance.app/guide/every-mitigation-strategy-has-two-halves
markdown_url: https://ensurance.app/guide/every-mitigation-strategy-has-two-halves.md
subtitle: "harden what you own, keep what you stand on. a peril-by-peril map of who does each half, who pays, and who gets credit today"
category: how-to
---

# every mitigation strategy has two halves

*harden what you own, keep what you stand on. a peril-by-peril map of who does each half, who pays, and who gets credit today*

**What are mitigation strategies?** For climate hazards, mitigation strategies have two halves. The structure half hardens what you own: the roof, the vents, the floor height. The living-system half keeps what shapes the hazard first: the forest's fuel, the floodplain, the marsh, the reef, the canopy. Codes and credits back the first half; the second is rarely paid for by those it protects.

Insurance calls this work mitigation; climate policy calls it adaptation ([mitigation means two different things](/guide/mitigation-means-two-different-things?from=guide)). Here is the map, peril by peril: who does each half, who pays and who gives credit.

The floodplain, the marsh, the reef and the forest shape the hazard that reaches a house whether or not anyone pays for them. They work for every building around them at once, which is why no single policyholder keeps them. [**Ensurance**](/manual/ensurance?from=guide) is designed as a way for the people who depend on that ground to pay for its keeping. It is not the floodplain, and it does not harden a roof.

## the first half works. do it

Hardening is measured, modeled and sometimes credited. The National Institute of Building Sciences (NIBS) found in 2019 that, on national averages, adopting current building codes saves $11 for every $1 spent and retrofitting existing private buildings saves about $4, while noting the ratios "can vary geographically." For wildfire, a 2020 study by the National Association of Insurance Commissioners (NAIC) with Risk Management Solutions (RMS) and the Insurance Institute for Business & Home Safety (IBHS) modeled nine communities in California, Colorado and Oregon. Moving from a neutral property setting, structural changes cut modeled risk by "up to 40%", and structural and vegetation changes together by "up to 75%".

Defensible space is the piece the evidence argues about. IBHS's 2020 analysis found it "an important characteristic of homes that survived the Camp Fire." A 2022 study of the same fire (Troy et al.) found that hardening mattered and that defensible space had "only a weak association" with survival. Do both. Neither is wasted.

Models see it too. When features such as roof-to-wall connections are in a building's data, "most catastrophe models can reflect the impact of these elements through vulnerability curves," says the NAIC's December 2024 draft primer. Whether a premium falls is the carrier's and the state's call: [does mitigation lower insurance premiums](/guide/does-mitigation-lower-insurance-premiums?from=guide).

## mitigation strategies by peril

"Practice" marks common practice, not a sourced finding. "Little" means the landscape does little, and the roof or the frame is the answer.

| peril | structure half | living-system half | who pays today | who credits it today |
|---|---|---|---|---|
| Wildfire | A Class A roof, vents screened with mesh no wider than 1/8 inch, no combustible items within 5 feet, with listed exceptions (IBHS standard, December 2025) | The fuel condition of the forest and the lots around the house, which in our reading shapes how many embers arrive. Thinning plus prescribed fire is the most effective treatment for lowering fire severity in stands (Prichard et al. 2021); that finding does not show fewer homes lost | The owner for the house; public land agencies and grants for the landscape (practice) | California rating plans must reflect a Class A roof, fire-resistant vents, clearing within 5 feet and community programs such as Firewise USA (rule operative October 2022) |
| Riverine flood | Federal minimum standards, adopted through local rules, require new and substantially improved homes in mapped high-risk zones to have the lowest floor at or above the base flood level (44 CFR 60.3). Dry flood proofing is the non-residential alternative (44 CFR 60.3). Wet flood proofing is "not defined in the NFIP regulations" and is Federal Emergency Management Agency (FEMA) guidance (Technical Bulletins 3 and 7) | Floodplain wetlands can lower flood peaks, but some wetlands raise floods; the support is "confined largely to floodplain wetlands" (Bullock and Acreman 2003) | The owner and federal grants for the building; whoever owns the floodplain for the floodplain (practice) | First floor height is among the National Flood Insurance Program's rating factors under Risk Rating 2.0 (FEMA, July 2025). Community floodplain management can earn a premium discount for every policy in the town through FEMA's [Community Rating System](/guide/what-the-community-rating-system-changes-on-a-flood-policy?from=guide) |
| Coastal surge | Elevation and above-code design (NIBS 2019 national average: $7 saved per $1 for surge) | Reefs cut waves; marshes and mangroves cut flooding. Wetlands avoided an estimated $625 million in direct flood damage in Hurricane Sandy (Narayan et al. 2017); reefs cut wave energy by an average of 97% (Ferrario et al. 2014); mangroves' flood protection is valued at over $65 billion a year worldwide (Menéndez et al. 2020). None stops every surge | The owner and federal grants for the building; public agencies and conservation groups for the coast (practice) | Elevation, through flood rating. None in the sources below for the marsh or the reef by name |
| Hurricane wind | Roof strength and covering, roof-to-wall straps, opening protection; FORTIFIED Roof, Silver and Gold | Little. Trees can lower or raise wind loads on a house, and they can fail (2025 wind-tunnel study). Reefs and mangroves work on the water; in our reading, not the wind | The owner (practice) | Florida law requires residential rate filings to include "actuarially reasonable" discounts, credits or deductible reductions for windstorm features; Citizens, the state-created insurer, requires a revised inspection form from April 1, 2026 |
| Heat | A cool roof reflects sun and lowers roof and indoor temperatures, and nearby air when applied at scale (Environmental Protection Agency, EPA) | Tree canopy. In one review of 308 studies cited by the EPA, urban forests averaged 3.0°F cooler than urban areas without green cover | The owner for the roof; cities and residents for street trees (practice) | No property premium credit we found |
| Hail | Impact-resistant roofing. In IBHS's 2025 ratings of 24 shingle products, most rated Good and none Excellent | Little. The roof is the answer (our reading; we found no source measuring a landscape effect) | The owner (practice) | Carrier by carrier, where filed (practice) |

Earthquake follows the hail pattern: NIBS's 2019 national average puts building retrofits at $13 saved per $1, and it lists no landscape measure.

Read down the last column: most credits sit on the structure half, and the floodplain enters mainly through community-level credit. The living-system half shows measured effects on fire severity, some floods, waves and heat, with the limits above.

## why the second half is underfunded

**It is shared.** A working floodplain can lower the water for every house downstream at once. No one policyholder can buy that benefit alone, and each can hope someone else pays ([what a source is worth paying for](/guide/what-a-source-is-worth-paying-for?from=guide)).

**It is off the lot.** Loss control mostly stops at the property line, as [the carrier's cheapest claim](/guide/the-carriers-cheapest-claim?from=guide) lays out. An owner cannot thin the forest above the street.

**The record is per building.** In the NAIC primer, mitigation enters a model through the building's own data: the roof, the connections, the openings. The condition of the forest above the street is not a feature of any one building, so it has no line on any one policy.

Grants, public land agencies and conservation groups fund some of it. What is rare is the people whose losses it lowers paying for it every year. Where that sits among your options is in [the four things you can do with a risk](/guide/the-four-things-you-can-do-with-a-risk?from=guide).

## the order of work

1. **Read the place.** Look up a US place's expected annual loss by peril at [place](/place?from=guide).
2. **Name the term you are moving.** Hardening moves vulnerability, retreat moves exposure, and the living system shapes the hazard ([hazard, exposure, vulnerability](/guide/hazard-exposure-vulnerability?from=guide)).
3. **Harden what you own first.** Use your peril's standard, get the inspection a credit requires, and keep the paper.
4. **Find what you stand on.** Name the forest, floodplain, marsh, reef or canopy that shapes your hazard, who keeps it, and whether its condition is holding.
5. **Keep it with the others who depend on it.** One source protects many at once; [split the bill for what lowers it](/guide/split-the-bill-for-what-lowers-it?from=guide) shows how a shared cost can be divided.

| who | structure half | living-system half |
|---|---|---|
| A homeowner | What your peril's standard calls for | Join the neighbors and the town in keeping the ground the street depends on |
| An insurer | Inspect, credit what is filed, and fund loss control on insured buildings | Recognize that the landscape across a zone does loss control for many policies at once |
| A town | Adopt and enforce current codes, and run the grant programs | Keep floodplains, marshes, forests and street trees in condition, and record it |

:::johnson
**harden what you own. keep what you stand on.**

The roof, the floor and the straps are yours to fix, and the field measures them and, in places, credits them. The forest, the floodplain and the marsh shape the hazard for everyone, so the people who depend on them need a way to pay together.

[look up your place's loss by peril →](/place?from=guide)
:::

## how ensurance carries the second half

Early in the build, here is how it is designed to work. A place holds an **account** in its own name, kept for its ground. The ground can be named in a **certificate**, and certificates and **coins** fund its keeping. Payments from the people who depend on the place go as **proceeds** to the ground's keeping first, then to the people doing the work, beside a condition record anyone can read. The [manual](/manual/ensurance?from=guide) has the detail.

What runs today: accounts, certificates and coins exist in the app, and [Risk Resilience](/risk-resilience.ensurance?from=guide) is the flow where this work belongs. Not yet proven: insurers or towns paying into a place's account as part of a mitigation strategy, and a condition record a carrier would credit. No ensurance account has lowered anyone's premium, and no credit is promised. It does not harden a roof, pay a claim or replace the first half.

## next steps

Carriers: [ensurance for insurers](/solutions/insurers?from=guide&topic=mitigation-and-adaptation). Cities and counties: [ensurance for governments](/solutions/governments?from=guide&topic=mitigation-and-adaptation). Landowners: [ensurance for landowners](/solutions/landowners?from=guide&topic=mitigation-and-adaptation). Or [talk to us](/contact?from=guide&topic=mitigation-and-adaptation) about your place.

## frequently asked questions

### what are mitigation strategies?

Plans to make a loss smaller before it happens. For climate hazards they have two halves: harden the building you own, and keep the living system that shapes the hazard before it arrives.

### does nature reduce wind damage to a house?

Not reliably. Trees can lower or raise wind loads and can fail. Reefs and mangroves are measured on waves and flooding, not wind. For wind, the roof and its connections are the answer.

### does ensurance lower my insurance premium?

No ensurance account has lowered a premium, and no credit is promised. A carrier credits work that is measured and filed. Ensurance is designed to fund the keeping and record the ground's condition.

This post is not insurance, engineering, legal or tax advice.

## sources

[NIBS, Natural Hazard Mitigation Saves: 2019 Report, fact sheet](https://nibs.org/wp-content/uploads/2025/04/ms_v3_exceeds_iwuic.pdf) — National benefit-cost ratios: adopt code 11:1, building retrofit 4:1; hurricane surge above code 7:1; earthquake building retrofit 13:1; "BCRs can vary geographically"

[NAIC Center for Insurance Policy Research, RMS and IBHS, Application of Wildfire Mitigation to Insured Property Exposure (2020)](https://content.naic.org/sites/default/files/cipr_report_wildfire_mitigation_0.pdf) — Modeled risk reduction up to 40% (structure) and up to 75% (structure and vegetation), nine communities in California, Colorado and Oregon

[IBHS, damage analysis of the 2017–2018 wildfires (July 2020)](https://ibhs.org/ibhs-news-releases/damage-analysis-of-2017-2018-wildfires-shows-importance-of-mitigation/) — "Defensible space was an important characteristic of homes that survived the Camp Fire"

[Troy et al., International Journal of Wildland Fire 31(6) (2022)](https://connectsci.au/wf/article/31/6/586/21844/An-analysis-of-factors-influencing-structure-loss) — Structural hardness mattered; defensible space "had only a weak association with structure survival"

[NAIC, Catastrophe Modeling Primer, exposure draft (December 2024)](https://content.naic.org/sites/default/files/inline-files/10_23_24%20Exposure%20Draft%20of%20Cat%20Modeling%20Primer.pdf) — Mitigation features in exposure data reflected "through vulnerability curves"

[IBHS, Wildfire Prepared Home Technical Standard (December 2025)](https://wildfireprepared.org/wp-content/uploads/WFPH-Technical-Standard-12-25.pdf) — Class A roof, 1/8-inch vent mesh, 0–5 foot noncombustible zone

[Prichard et al., Ecological Applications 31(8) (2021)](https://escholarship.org/content/qt1w52p1dp/qt1w52p1dp.pdf) — Thinning plus prescribed burning most effective at reducing fire severity; a stand-level finding

[Cal. Code Regs. tit. 10, § 2644.9](https://www.law.cornell.edu/regulations/california/10-CCR-2644.9) — Mandatory wildfire mitigation factors in rating plans, operative October 14, 2022

[FEMA, Community Rating System](https://www.fema.gov/flood-insurance/rules-legislation/community-rating-system) — Communities earn classes for floodplain management that discount flood insurance premiums for policies in the community

[44 CFR § 60.3](https://www.law.cornell.edu/cfr/text/44/60.3) — Residential lowest floor elevated to or above the base flood level in Zones A1-30, AE and AH; non-residential may be floodproofed

[FEMA, NFIP Technical Bulletin 3 (January 2021)](https://www.fema.gov/sites/default/files/documents/fema_technical-bulletin-3_1-2021.pdf) — Dry floodproofing defined for the NFIP; "'Wet floodproofing' is not defined in the NFIP regulations"

[FEMA, NFIP Technical Bulletin 7 (May 2022)](https://dnrc.mt.gov/_docs/water/Floodplains/Permits-Regulations/2022fema_nfip-technical-bulletin-7-wet-floodproofing-guidance.pdf) — Wet floodproofing guidance: floodwater allowed to enter and exit to balance pressure on walls

[FEMA, Understanding Risk Rating 2.0 (July 2025)](https://agents.floodsmart.gov/sites/default/files/media/document/2025-08/fema-understanding-risk-rating-2.0-fact-sheet-2025.pdf) — Rating factors include building characteristics such as first floor height

[Bullock and Acreman, Hydrology and Earth System Sciences 7(3) (2003)](https://hess.copernicus.org/articles/7/358/2003/) — Wetlands can reduce or increase floods; support for flood control "confined largely to floodplain wetlands"

[Narayan et al., Scientific Reports 7 (2017)](https://www.nature.com/articles/s41598-017-09269-z) — Wetlands avoided an estimated $625 million in direct flood damages during Hurricane Sandy

[Ferrario et al., Nature Communications 5:3794 (2014)](https://www.nature.com/articles/ncomms4794) — Coral reefs reduce wave energy by an average of 97%

[Menéndez et al., Scientific Reports 10 (2020)](https://www.nature.com/articles/s41598-020-61136-6) — Mangroves provide flood protection benefits exceeding $US 65 billion per year

[IBHS, FORTIFIED](https://fortifiedhome.org/) — Voluntary construction and re-roofing program with Roof, Silver and Gold designations

[Fla. Stat. § 627.0629](http://www.leg.state.fl.us/statutes/index.cfm?App_mode=Display_Statute&URL=0600-0699/0627/Sections/0627.0629.html) — Residential rate filings must include discounts for windstorm loss-reduction features

[Citizens Property Insurance Corporation, inspection form bulletin (2026)](https://www.citizensfla.com/-/20260319-uniform-mitigation-verification-inspection-form-changes) — Revised inspection form required for inspections on or after April 1, 2026

[UF/IFAS summary of Ibrahim et al., Journal of Wind Engineering and Industrial Aerodynamics (2025)](https://blogs.ifas.ufl.edu/gcrec/2025/08/07/friend-or-foe-are-trees-protecting-your-home-from-hurricanes-or-putting-it-in-peril-tree-journal-club-8/) — Trees reduced wind suction in some configurations and made it worse in others; trees can fail

[EPA, Using Cool Roofs to Reduce Heat Islands](https://www.epa.gov/heatislands/using-cool-roofs-reduce-heat-islands) — Cool roofs reduce temperatures on the roof, inside the building and, at scale, in the surrounding air

[EPA, Benefits of Trees and Vegetation](https://www.epa.gov/heatislands/benefits-trees-and-vegetation) — One review of 308 studies found urban forests averaged 3.0°F (1.6°C) cooler than urban non-green areas

[IBHS, 2025 impact-resistant shingle ratings (November 2025)](https://ibhs.org/ibhs-news-releases/ibhs-releases-its-most-expansive-impact-resistant-shingle-ratings-to-date/) — 24 products rated; most Good, none Excellent

## the series

1. [mitigation means two different things](/guide/mitigation-means-two-different-things?from=guide) — **Read first:** In climate policy, mitigation cuts emissions and adaptation cuts the damage; in insurance, mitigation is the adaptation
2. [hazard, exposure, vulnerability](/guide/hazard-exposure-vulnerability?from=guide) — The three things a loss is made of, and which one each kind of mitigation moves
3. [what home hardening does, and where it stops](/guide/what-home-hardening-does-and-where-it-stops?from=guide) — A ready house keeps embers out; how many arrive is shaped by the land around it
4. [flood proofing raises the house. the floodplain lowers the water](/guide/flood-proofing-raises-the-house-the-floodplain-lowers-the-water?from=guide) — Elevation, dry and wet flood proofing change the damage; the depth that arrives is shaped upstream
5. [wind mitigation is the house's job. the surge is the coast's](/guide/wind-mitigation-is-the-houses-job?from=guide) — The roof and its connections hold the wind; reefs, mangroves and dunes work on the water
6. [managed retreat leaves land behind](/guide/managed-retreat-leaves-land-behind?from=guide) — A buyout moves the exposure; the land it leaves can become floodplain someone has to keep
7. [every mitigation strategy has two halves](/guide/every-mitigation-strategy-has-two-halves?from=guide) — Harden what you own, keep what you stand on: a peril-by-peril map