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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.

Leveraging adaptive comfort - the three-zone strategy

The three-zone approach arranges a building's form, functions and detailed layout around its context, the wind and the sun's path, so it can operate passively whenever necessary.

Next, designers should use the 'three zone' approach, to help arrange the building's form, functions and detailed layout.

This helps decide on the best responses to its urban or rural context, wind directions (for cross ventilation cooling and heat shedding), and the sun's daily path - anticipating the intensity of solar radiation falling on different parts of the building during the days, months and year.

Why the zones exist

Because ARC is aiming for both Step 1 and Step 2 buildings to be able to operate during periods of disruption, including to the electricity supply, the three-zone approach should be used to create buildings that can operate in naturally ventilated, passive mode whenever possible or necessary.

No ARC-compliant building should be completely reliant for the thermal safety of its occupants on electricity-dependent mechanical systems alone, including systems using solar and battery backup.

What applies to every zone

All zones should be secure, insect-protected, well-shaded, and able to be effectively naturally ventilated. The building should also offer its occupants a survivable refuge from extreme heat events - see designing a heat refuge.

The three zones

Zone
1 Mechanically cooled and ventilated Zone 1
2 Communal heat refuge, naturally ventilated Zone 2
3 Transient and buffer spaces Zone 3

Diagrams not yet included

The source refers here to three illustrations: a notional building with only zones 2 and 3 incorporated; the same notional building with zones 1, 2 and 3; and a design for a school in Tanzania showing the use of zone 3 'buffer spaces' on the east and west elevations to help shade zone 1 and 2 rooms. They carry a note to the author - "redo: plan to ppt, with same zone colours" - and have not yet been prepared for the wiki.


Source: ARC Technical Criteria - Leveraging adaptive comfort: the 3-zones strategy
Pattern · confidence high · Imported 2026-08-29, not yet reviewed · next review 2026-11-29
Tags: framework, zones, design-strategy, passive-design
Citation key: three-zones-strategy