Unwritten answers PRI Questions for Climate Physical Risk Providers [2026 Update]

The UN Principles for Responsible Investment (PRI) published a technical guide on physical climate risk assessment for private market investors. It includes a list of questions to ask providers when procuring a physical risk tool (page 19).

Unwritten first answered those questions in 2025. This post provides updated responses to reflect our updated methodology and offerings.

Physical risk should not be assessed in isolation, because physical, transition and nature risks overlap. Unwritten assesses all three and shows how they interact. This post, like the PRI guide, focuses on Unwritten's physical risk module.

What has changed since 2025?

• AI climate due diligence. Unwritten's AI Climate Due Diligence Tool produces a diligence report on a target in minutes. The report combines scenario modelling with deep research on historic climate shocks, peer performance, competitor adaptation and regulatory context.
• Asset damage alongside revenue loss. Diligence outputs now quantify both asset damage and business interruption for each key risk item.
• Portfolio correlation risk. Unwritten flags where a new acquisition adds to climate exposure already held across the portfolio.
• Sequenced adaptation plans. Adaptation measures are sequenced across the hold period and carried into the value creation plan.
• Site-level access for PortCos. Unwritten Workspaces gives portfolio company (PortCo) teams their own site-level physical risk assessments.
• Evidenced sources and diligence gaps. Every finding is traceable to a source, and missing data is listed explicitly.

PRI Section 1: How does the provider support my strategic objectives?

1.1 How can Unwritten's outputs be integrated into the investment process and strategic decision-making?

Quick answer: Unwritten is built for each stage of the private markets investment cycle, and its outputs match the decision being made at each stage.

• Pre-deal screening: Qualitative risk scoring for quick triage of targets and sites.
• Due diligence: an AI-generated climate due diligence report, produced in minutes, with key risk items, value creation plans and diligence gaps.
• Investment committee (IC): quantified impact metrics, peer comparisons and evidence for every finding, so physical risk can be weighed alongside the investment case.
• Ownership and value creation: cost- and impact-assessed adaptation measures, sequenced across the hold period, plus ongoing monitoring at site level.
• Reporting and exit: portfolio-level exports and reporting outputs for LPs and disclosure frameworks.

Commentary: To use a physical risk tool well, investors need a plan for which decisions it will inform. Climate risk insights often fail to change decisions because they are produced in a vacuum, without historic context, peer benchmarks or a clear action. Unwritten's due diligence memo is designed to close that gap, being clear enough for the deal team and rigorous enough for the IC.

1.2 Does Unwritten offer education to investment teams to interpret outputs correctly?

Quick answer: Yes. Workshops and training for deal teams and sustainability teams are included in the licence fee.

Commentary: Expressing physical risk in financial terms is not enough on its own. Dealmakers need to understand how the numbers were calculated, so Unwritten evidences the source behind every finding and documents its models in full within the platform.

PRI Section 2: How do the provider’s services and outputs support my physical risk assessment process?

2.1 What types of assets does Unwritten cover?

Quick answer: Around 60 asset archetypes, from cold storage warehouses to railways to nursing homes. Linear and area assets are also supported (see 2.7).

Commentary: Different assets need different modelling. A physical risk tool should reflect hazard intensity, hazard likelihood, exposure (the asset’s location) and vulnerability (how severely the hazard affects that type of asset).

2.2 Which physical hazards does Unwritten cover?

Quick answer: By default, Unwritten covers drought, wildfire, cyclone, river flooding, rain flooding, coastal flooding, storm surge, extreme heat and cold waves. Additional hazards can be configured on request. Unwritten's nature model also covers water scarcity and dependency on air and soil quality.

Commentary: Which hazards matter depends on the portfolio. Subsidence is especially relevant to real estate, while heat stress on crops and livestock is critical for agricultural exposure.

2.3 Does Unwritten cover my geographic area of focus?

Quick answer: Unwritten has global, high-resolution physical risk coverage. Resolution varies by hazard and region; for example, cyclone data is coarser than flood data because cyclones affect wide areas.

Commentary: For portfolios concentrated in one city or region, investors can use Unwritten for triage and then procure specialist data for deep dives where materiality is high. Unwritten's due diligence memo also lists diligence gaps, which shows where further site data is needed.

2.4 Do Unwritten's climate scenarios align with my objectives and reporting needs?

Quick answer: Unwritten uses IPCC scenarios SSP1-2.6 to SSP5-8.5 by default. Default time horizons are 2035 and 2050, with others on request, and return periods can be customised. In due diligence, impacts are evaluated across the expected hold period.

Commentary: Three scenarios meet the requirements of IFRS S2- and TCFD-aligned disclosure regimes. Unwritten's transition risk module adds NGFS-style scenarios (Net Zero 2050, Below 2°C, Delayed Transition and NDCs) and custom carbon price scenarios.

2.5 Does Unwritten use open-source, private or proprietary data?

Quick answer: A combination. Unwritten builds on open, internationally agreed climate frameworks and layers in proprietary models, commercial data and AI-led deep research.

Commentary: In due diligence, Unwritten's AI adds market intelligence that hazard models alone do not provide. This includes disruption from historic climate shocks, how peers fared and what competitors are doing to adapt.

2.6 Is Unwritten transparent about its models, methodologies and update frequency?

Quick answer: Yes. All data and models in Unwritten are documented in the platform, product roadmaps are shared with customers, and release notes accompany every model update. In AI-generated diligence, every finding is evidenced with its source.

Commentary: Access to model documentation is critical for interpreting and validating results. With AI-generated analysis, source traceability matters just as much, so deal teams and ICs can check each claim.

2.7 Can Unwritten assess linear and area assets?

Quick answer: Yes. Users can upload line and area assets to Unwritten and view both aggregate and sample-level results.

Commentary: Risk varies along a road, railway or large agricultural site, so the whole asset should be sampled to find hotspots.

2.8 Does Unwritten's methodology consider vulnerability?

Quick answer: Yes, in five ways.

1. Asset archetypes reflect the different vulnerabilities of each asset type.
2. Users can toggle defended or undefended risk for relevant hazards.
3. Users can record whether an asset already has mitigation measures in place.
4. Every hazard at every asset comes with suggested adaptation measures that are cost- and impact-assessed.
5. Due diligence draws on how the target and its peers actually performed during past climate shocks, which grounds vulnerability in observed outcomes.

Commentary: In private equity, vulnerability also depends on the business model, insurance cover and the deal structure. Unwritten's diligence memo lists these as diligence gaps when they are unknown, for example insurance terms by site or ownership type for each asset.

2.9 Does Unwritten's methodology include non-physical damage impacts?

Quick answer: Yes. Unwritten models business interruption as outage days, including access disruption; for example, flooding near an office stops staff getting to work even if the building is undamaged. Live risk monitoring tracks events such as power cuts caused by high winds. Unwritten's transition and nature modules cover policy, legal and market responses.

Commentary: Loss of power, site access, worker welfare and rising insurance premiums can hurt a business without any direct damage. These effects matter most for assets with concentrated revenue, such as specialised manufacturing sites.

PRI Section 3: What outputs, including financial metrics, does the provider generate?

3.1 What financial metrics does Unwritten generate, and on what assumptions?

Quick answer: Unwritten calculates potential revenue loss for every hazard at every asset, aggregated at company, fund and firm level. In due diligence, key risk items also show estimated asset damage. Underlying hazard data, outage day bands and all assumptions (scenario, time horizon, return period) are available separately for use in investors' own models.

• Revenue loss is based on modelled outage days, which depend on hazard type, asset archetype and hazard severity. For example, 10 outage days from flooding at a solar farm earning $100,000 a day means $1 million in lost revenue.
• Asset damage is expressed as a share of asset value. For example, a key risk item for an extreme storm surge might show 1.4 metres of water depth, more than 180 outage days and 20–30% asset damage.

Commentary: Financial metrics translate hazard into materiality. A low risk to a factory critical to production can matter more than a high risk to a small distribution site. Each financial metric adds assumptions to the hazard data, so Unwritten surfaces those assumptions and supports metrics with historic evidence from past climate shocks and peer outcomes.

3.2 How are Unwritten's risk scores defined and calculated?

Quick answer: Risk score methodology differs by hazard and by asset archetype, and is documented in full within the platform.

Commentary: RAG ratings vary widely between providers; one may rate any flooding as high risk, another only severe inundation. Scores should also vary by archetype, because the same flood means different things for an office and for a farm.

3.3 Will Unwritten's outputs support my reporting and disclosure requirements?

Quick answer: Yes. Unwritten's reporting module is built on reviews of hundreds of ISSB disclosures and client insight into LP reporting requirements. It supports IFRS S2- and TCFD-aligned disclosures, and the adaptation measures Unwritten proposes help meet rules such as California's SB 261, which asks disclosers to describe how they are mitigating physical risks.

Commentary: Most climate disclosure regimes follow the TCFD framework now overseen by the ISSB, but their implementations differ. Unwritten publishes an annual disclosure benchmarking report and free disclosure templates for different jurisdictions.

About Unwritten

Unwritten is a London-based climate risk platform for private markets. Its platform, Unwritten AI, helps private equity and infrastructure investors assess physical, transition and nature risk at fund, portfolio company and site level.

The platform uses artificial intelligence to automate complex climate risk data workflows and drive value-creation opportunities for private markets investors, asset managers and corporate risk leaders. Unwritten helps leaders move beyond minimum compliance to actively manage risk and build operational resilience that creates value at the PortCo level.

To learn more, visit unwritten.co/private-markets.