Skip to content
Draft. These pages were imported from the ARC Technical Criteria document (16 April 2026) and have not yet been reviewed in this format. Several thresholds are still being settled and are flagged on the pages concerned.

Success criteria - the temperature thresholds

Zone 1 and 2 spaces should remain below the comfort model's humidity-adjusted thresholds for at least 90% of the time. Separate thresholds apply during heatwave conditions.

Everyday conditions

Monitored rooms designated as zones 1 and 2 should remain below the upper range of the comfort model's humidity-adjusted temperature thresholds for ≥ 90% of the time - that is, that these are not breached for more than 10% of the time each year.

The thresholds themselves come from the comfort model, and depend on local humidity.

During heatwave conditions

However, during heatwave conditions zone 1 and 2 spaces may become temporarily hotter, and the following temperature thresholds apply:

  • Humid climates: a maximum limit of 32 °C dry bulb air temperature, or a wet bulb temperature of 35 °C.

The heat refuge requirement is that it remains below 32-35 °C through passive design measures.

For spaces people pass through rather than occupy, see transient spaces.

Open questions on this page

The source document leaves these unresolved

These are the author's own queries, at exactly these points in the source. They are reproduced rather than removed, because these are safety thresholds and presenting them as settled would be misleading.

  • The humid-climate limit is written as "a maximum limit of 32C dry bulb air temperature) (or 32-35C?)". The upper figure is still under discussion.
  • "Who designates a period as an 'official heatwave'?" is recorded as an open question. It matters, because it decides which set of thresholds applies. See defining heatwaves.
  • No corresponding limit for dry climates is given in this section, although transient spaces gives 40 °C for hot dry climates.

Confirm any of these with ARC before relying on them for a project.

Source: ARC Technical Criteria - Comfort model - Criteria
Reference · confidence medium · Imported 2026-08-29, not yet reviewed · next review 2026-11-29
Tags: criteria, thresholds, comfort, heatwaves, compliance
Citation key: success-criteria