Climate as Physical Risk

Disclosure asks an owner to describe exposure. Buildings ask an owner to deal with it. The two meet only when the reported risk is translated into elements, actions and timing. A flood exposure becomes a question about where the main switchboard, lift motors and pumps sit relative to likely water levels. A heat exposure becomes a question about cooling capacity, plant ratings and envelope performance. A storm exposure becomes a question about roof fixings, gutters, downpipes and facade anchors.

Many existing buildings were designed for a climate envelope that is shifting. Drainage sized for historic rainfall intensities, plant selected for historic peak temperatures, roofs fixed for historic wind loads. None of that makes a building unsafe by default. It does mean the margins are thinner than they were.

Insurers have been pricing physical risk ahead of most owners, though not in a straight line. Headline commercial property rates have been falling since 2024 as reinsurance capacity returned: Marsh reported global property rates down 10 per cent in the third quarter of 2026. That is the insurance cycle, not the hazard. Exposure still reaches a building through deductibles, sub-limits, exclusions and rebuild-cost inflation, and in the most exposed locations through cover that is hard to place at all. Australian home premiums rose an average of 7.2 per cent a year between 2010 and 2025, against 3.1 per cent wage growth, according to APRA. In Britain, the Flood Re scheme supports household flood cover but does not extend to commercial property, which is priced on its own exposure.

When insurance becomes the first place a physical risk is priced, the building’s condition and configuration start to show up in its operating cost, its financeability and its sale.

An owner who can show what has been done, flood barriers, raised plant, upgraded drainage, can argue for better terms. One who cannot is priced on the assumption that nothing has.

Because headline commercial rates are falling, it is tempting to read physical risk as easing. The signals in the market say otherwise, once they are separated.

Physical risk reaches a commercial building through more than the premium. Deductibles and sub-limits for flood, storm and hail determine how much of a loss the owner carries. Rebuild-cost inflation raises the sum insured, and with it the premium, even where the rate falls. Lenders increasingly ask for evidence of resilience before they will finance an exposed asset. And in the most exposed locations, the question is not price but whether cover can be placed at all.

For the register, this means the resilience items in this paper, plant location, drainage capacity, roof drainage and cooling margins, are not only about avoiding damage. They are about keeping the building insurable on terms that a buyer and a lender will accept.

Physical climate risk concentrates in a familiar set of elements. Roof drainage and box gutters. Basements, ground-floor plant and electrical rooms. Cooling plant and its capacity margin. Facade sealants, fixings and glazing. External ground levels and site stormwater. Bushfire-exposed vents, gutters and combustible elements on urban fringes.

These are ordinary register items. What changes is how they are read. A gutter at mid-life might be a 6–10 year item on condition alone, and a 2–5 year item once its capacity against current rainfall intensity is considered. That is the kind of judgement we discuss in Timing Is Not Risk: risk changes the case for acting, while timing still follows the evidence.

A resilience reading starts with exposure and ends with elements. Exposure comes from hazard mapping and history: flood levels, overland flow paths, bushfire overlays, wind regions, heat. Elements come from the building: where the main switchboard, lift motors, pumps and generators sit relative to plausible water levels; how roof drainage, box gutters and overflows are sized against current rainfall intensities; how much margin cooling plant has on hot days; how facades and roof fixings are designed for wind; what vents, gutters and combustible elements face fire.

Joining the two produces a short list of targeted works: raising or protecting critical plant, adding overflow capacity, upgrading fixings, ember-proofing vents, adding cooling margin. Most are modest. Their value lies as much in what they show an insurer or lender as in what they prevent.

The step itself is modest. Identify the elements that carry the building’s climate exposure, check them against current conditions rather than design-era assumptions, and decide which deserve earlier attention. Most will be targeted works rather than wholesale change.

Portfolio heat maps hide this. Two buildings on the same flood map can carry very different exposure depending on where their plant sits and what has already been done, which is a reason to look below the map at the building. Insurance markets move, and the pressure on particular elements will follow claims evidence rather than this paper.