Building a Climate-Adjusted Pro Forma

EPISODE DESCRIPTION
Miami-Dade County, Florida is one of the most intensively studied climate-risk real estate markets in the world — and simultaneously one of the most active investment markets in the United States. It illustrates Signals 4, 1, and 6 in concentrated form: a measurable and growing valuation gap between appraised and climate-adjusted values; an insurance market that experienced acute structural failure and remains vulnerable to recurrence; and chronic operating cost escalation from extreme heat days and sea-level rise that is already on the expense line, not in a projection.

In this Strategy & Underwriting brief, host Jamie Wolf builds a climate-adjusted pro forma from the ground up around a real deal scenario: a 200-unit multifamily acquisition in Homestead, Florida, purchased in mid-2021 for $38 million at a 6.5 percent cap rate with a target IRR of 8.2 percent. By 2026, insurance alone has doubled to $1.68 million per year — a $840,000 annual NOI reduction that implies a 34 percent value-erosion event at the original cap rate. Adding HVAC cost escalation, the total unmodeled NOI drag approaches $936,000 annually, implying 38 percent value erosion across just two line items.

The episode delivers a four-step underwriting framework — climate-adjusted valuation, three-scenario insurance modeling, chronic cost escalation on each operating line, and a climate-adjusted exit cap rate assumption — and closes with three strategic responses: Reprice, Reposition, or Redirect. The takeaway tool: add the three-scenario insurance model to every underwriting model before signing any purchase and sale agreement.

Episode Summary

Episode 14 answers the practical question that follows Episode 13’s institutional capital map: how do you actually model climate risk in a deal? The vehicle is a detailed case study — a 200-unit Homestead, Florida multifamily acquired in 2021 for $38 million, with conventional underwriting that has been overtaken by climate-driven operating cost escalation. Insurance doubled over five renewal cycles to $1.68 million per year, producing a $840,000 annual NOI reduction and a DSCR that now sits directly on the lender covenant at 1.20x. HVAC cost escalation adds $96,000 in additional annual drag. Combined, the unmodeled deterioration approaches $936,000 annually — a $14.4 million value erosion at the original cap rate, representing 38 percent of the purchase price, from two line items.

The four-step underwriting framework builds from the valuation layer (FEMA flood zone check, insurer market depth, climate-adjusted comp cap rates) through three-scenario insurance modeling (Base at 10% annual escalation, Moderate at 20% with a carrier non-renewal, Severe with tripling premiums and a forced flood endorsement), chronic cost escalation per operating line (3% above CPI for HVAC utilities), and a climate-adjusted exit cap rate (7.25% versus the 6.5% entry rate). Three-scenario IRR outputs: Base 4.9%, Moderate 3.8%, Severe 1.6% — against an original underwriting of 8.2%. The Moderate scenario breaks most institutional hurdle rates of 6 to 7 percent; the Severe scenario is a wealth-destruction event.

Three strategic responses frame the conclusion: Reprice using the climate-adjusted pro forma as a defensible price negotiation tool; Reposition by building $415,000 in hardening capex into the acquisition thesis from day one; or Redirect — recognizing that the deal you do not do is often the best return you ever generate.

Key Takeaways

• Miami-Dade County illustrates all three signals in concentrated form: valuation gap (S4), insurance market structural risk (S1), and chronic operating cost escalation from heat and sea-level rise (S6). The pro forma framework built here applies to every coastal, Sunbelt, and wildfire market where the signals are moving.
  
  
• The case deal: 200-unit multifamily, Homestead FL, acquired mid-2021 for $38M at 6.5% cap, 8.2% target IRR. By 2026, insurance has doubled to $1.68M/year — a $840K annual NOI reduction. DSCR now sits at 1.20x, directly on the lender covenant. No hurricane. No recession. No operational failure.
  
  
• Signal 4 math: at a 6.5% cap rate, $840K in NOI reduction implies a $12.9M market value decline — a 34% value-erosion event from insurance alone. Adding $96K in HVAC cost escalation: $936K total unmodeled NOI drag, $14.4M total value erosion — 38% of original purchase price — from two line items.
  
  
• The Homestead property is partially in FEMA Zone AE (1% annual flood probability — the 100-year flood plain). This designation was freely available in 2021 public FEMA records. It was not obtained at underwriting.
  
  
• Climate-aware institutional buyers are currently pricing flood-zone multifamily in Miami-Dade at cap rates 50 to 120 basis points wider than equivalent non-flood-zone assets. The climate-adjusted value of the Homestead property at closing was approximately $31 to $33 million — a $5 to $7 million valuation gap that existed at the moment of original closing, not in hindsight.
  
  
• Step 2 — Three-Scenario Insurance Model: Base ($1.68M, +10%/yr), Moderate ($1.68M, +20%/yr with one carrier non-renewal mid-hold), Severe (premiums triple within three cycles, forced flood endorsement added at year four). Obtain at least three actual carrier quotes — do not use the broker’s budgeted figure.
  
  
• Step 3 — Chronic Cost Escalation: model 3% annual HVAC utility escalation above CPI. Hardening capex: $180K impact-resistant windows/doors + $95K backup generator + $140K electrical infrastructure elevation = $415K total. Model this as a value-creating investment carried at exit, not a sunk cost.
  
  
• Step 4 — Climate-Adjusted Exit Cap Rate: use 7.25% exit versus 6.5% entry. The exit buyer faces the same or worse insurance market and a narrower qualified buyer pool. The 75-bps cap rate expansion alone significantly compresses the exit multiple.
  
  
• Three-scenario IRR results: Base 4.9% / Moderate 3.8% / Severe 1.6% — versus 8.2% original underwriting. To generate an acceptable return under the Moderate scenario, the deal required a purchase price of approximately $30–31 million — an 18 to 20 percent discount to the actual $38M transaction.
  
  
• Three strategic responses to the climate-adjusted pro forma: Reprice (use the data as a defensible price negotiation tool); Reposition (build hardening capex into the acquisition thesis at closing); Redirect (the deal you do not do is often the best return you generate).
  
  
• Caution on FEMA flood zone appeals (Letter of Map Amendment): an approved appeal does not mean the property won’t flood — referenced directly in the script via Camp Mystic and the Guadalupe River flood.
  
  
• Practical takeaway: add the three-scenario insurance model to every underwriting model you run. If the Moderate scenario breaks the lender covenant or drops IRR below the fund hurdle rate, you have your answer before signing the PSA. The CRDF Deal Stress Test™ is available free at climatereadyre.com.
  
  

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• Next episode: Green Premiums and Brown Discounts

References & Sources Cited

• FEMA Flood Zone Designations — Zone AE: 1% annual flood probability (100-year flood plain); publicly available via FEMA Flood Map Service Center; msc.fema.gov
  
  
• Citizens Property Insurance Corporation — Florida state-backed insurer of last resort; established 2002; peaked at >1.4 million policies in 2023; Florida Office of Insurance Regulation
  
  
• Florida Insurance Market Reforms — tort and litigation reforms enacted 2022 and 2023; resulting private market stabilization and new market entrants documented
  
  
• Florida Building Code — 8th Edition (2023); incorporates ASCE 7-22 engineering standards; updated ultimate design wind speed maps; enhanced roof uplift, cladding, and water resistance requirements
  
  
• NOAA Tide Gauge Data — South Florida sea-level rise documentation; approximately 3 to 9 mm/year (recent measurements at higher end of range); tidesandcurrents.noaa.gov
  
  
• Miami-Dade Heat Data — increase in days above 90°F from 84 to 133 per year since 1970; chronic heat index projections; NOAA and Miami-Dade County Office of Resilience
  
  
• CBRE Miami Capital Markets — cited for ongoing regional commercial and multifamily transaction metrics; real-time cap rate differentials for flood-zone vs. non-flood-zone assets (50–120 bps documented spread)
  
  
• ASCE 7-22 — American Society of Civil Engineers Minimum Design Loads and Associated Criteria for Buildings and Other Structures; incorporated into Florida 8th Edition Building Code
  
  
• Camp Mystic / Guadalupe River Flood — referenced as cautionary example of FEMA flood zone appeal (Letter of Map Amendment) that did not prevent actual flooding
  
  

DISCLAIMER
Climate-Ready Real Estate Investing is an independent intelligence briefing. We synthesize publicly available research, industry reporting, and primary data sources — sometimes with the assistance of AI-enabled analytical tools — into commentary and analysis on the trends shaping real estate, climate risk, and the long-term durability of communities. The goal is to surface patterns and questions that investors, lenders, insurers, policymakers, and industry participants may wish to consider.

Data, statistics, and regulatory information cited in this episode reflect sources available at the time of publication. Market conditions, fund figures, and regulatory requirements may have changed. Listeners should verify time-sensitive information before making investment decisions.

The views expressed are analysis and commentary, not personalized advice, and the material may contain errors, omissions, or interpretations that differ from other analyses. Nothing in this publication constitutes investment, financial, legal, tax, or other professional advice. Companion interactive dashboards (including the CRDF Signal Tracker™  and the CRDF Deal Stress Test™) are illustrative tools; any examples or archetypes referenced are composites drawn from publicly observable market data, not specific named assets or transactions. Listeners and readers should conduct their own due diligence and consult qualified professionals before making decisions.

The views and opinions expressed by guests are theirs alone and do not represent those of the show, host, or company. 

What is Climate-Ready Real Estate Investing?

Climate Ready Real Estate Investing is an intelligence briefing for professionals tracking how climate risk, insurance market disruption, migration trends, infrastructure stress, and resilient development are reshaping real estate investing. Hosted by WSJ bestselling author Jamie Wolf, the show translates climate signals into practical strategies for underwriting, asset protection, capital allocation, development planning, housing demand, and long-term property value. Covering real estate markets, insurance costs, climate migration, resilient construction, infrastructure investment, and durable asset design, each episode helps investors, developers, lenders, private equity firms, insurers, and supply chain leaders identify emerging risks, protect portfolios, and position for opportunity in a changing market.