Codes, Not Concepts: Toward A Lunar Building Standard For Pressure, Fire, And Egress

Why “habitat as a machine” needs rules that engineers, insurers and crews can trust

The first generation of lunar structures will be closer to submarines than houses: sealed pressure vessels sitting in vacuum, with oxygen-enriched interiors, limited crew egress routes and maintenance performed far from fast rescue. A building standard that treats a habitat as life-critical machinery—covering pressure, fire, and egress—is therefore not a nicety but the economic and safety backbone of operations. The ingredients exist in today’s human-spaceflight rules and research; the work is to adapt them to a static, surface-based context.

Why a lunar code is not a copy of Earth’s life-safety playbooks

Earth building codes rely on breathable outside air, fire brigades and evacuation to a safe exterior. None of those assumptions hold on the Moon. NASA’s human-systems standard NASA-STD-3001 Volume 2 already sets system-level requirements for human space systems—pressure control, atmosphere management, emergency response, habitability—which provide the natural starting point for habitat criteria; the standard was revised in 2023 and remains the agency’s backbone for crewed environments.

Pressure integrity and atmosphere management

Structural margins and leak-before-burst behaviour require explicit definition because vacuum outside and oxygen-rich inside make decompression and fire the two dominant hazards. Spaceflight rules specify minimum relief capacity, monitoring and fault-tolerant controls; on the surface these translate into habitat sections that can be isolated, with hatches and valves sized for rapid pressure equalisation between compartments. NASA’s habitat layout work for Artemis—examining internal zoning for EVA servicing, hygiene and work areas—underscores the link between internal architecture and pressure safety: traffic patterns, airlocks and “dirty/clean” segregation become part of the safety case, not just convenience.

Radiation and thermal realities amplify the pressure story. Continuous occupancy drives cumulative dose management and night-survival power planning, but those are managed risks if the habitat holds pressure reliably and can be safely entered after excursions. Empirical dose measurements from the Lunar Lander Neutron and Dosimetry instrument (average ~1.37 mSv/day in quiet solar conditions) demonstrate why longer stays will push more mass into shielding and storm shelters, which in turn affects structural and pressure design.

Fire behaviour in oxygen-enriched interiors

The Apollo 1 accident remains the canonical lesson: elevated oxygen partial pressure and flammable materials can turn a small ignition into a fatal event. Modern standards address this directly. NASA-STD-6001 defines flammability, offgassing and compatibility testing for materials in crewed environments, and spacecraft fire research has moved from bench tests to full-scale trials. The Saffire series, culminating in Saffire VI (2023–24), burned large samples inside uncrewed Cygnus spacecraft to characterise growth, toxic products and sensor performance at relevant oxygen levels and flow regimes—evidence that now informs detection thresholds, suppression choices and layout. A lunar code would draw on this body of test data rather than reinvent it.

Two implications follow for surface structures. First, material selection is not aesthetic: textiles, foams, cable jackets and interior finishes must meet oxygen-environment flammability limits with documented test pedigree. Second, compartmentalisation—doors, valves, and smoke control in a sealed volume—substitutes for external evacuation. The objective is survivable conditions long enough to shelter in place in an adjacent compartment or reach a pressurised rover, not to run outside.

Egress, refuge and the meaning of “outside”

On Earth, egress ends at fresh air. On the Moon, egress typically ends at another pressurised volume—a safe room, a rover or a short, shielded tunnel to a secondary module. Artemis habitat studies show interior zoning and traffic shaping for suit maintenance and EVA prep that can double as refuge pathways under smoke or loss-of-pressure scenarios; pairing a fixed habitat with a pressurised rover adds a mobile refuge that extends options when a module is compromised. The egress problem is therefore architectural: hatch clear dimensions, handleability in gloves, floor-plan routes with low snag risk, and external interfaces that can be operated in dust and cold.

Inspection, certification and the link to insurability

A code earns its keep when it supports repeatable inspection and certification. NASA-STD-3001 provides the language for verifiable requirements; Artemis surface-habitat research adds concrete design artefacts (pressure-zone layouts, airlock duty cycles, maintenance bays) against which to inspect. Fire safety becomes auditable through material certifications to NASA-STD-6001, documented oxygen set-points and alarm/fail-safe logic proven in integrated tests; spacecraft fire data from Saffire further anchor acceptance criteria for detection and suppression. Insurers and programme authorities require this level of documented conformity before underwriting long-duration occupancy.

What Artemis implies for the first standard

NASA’s public architecture papers position a surface-first stack—foundation habitat, unpressurised and pressurised rovers, and dependable power—rather than immediate subsurface estates. That choice shapes code priorities: internal pressure zoning and isolation, oxygen-environment material control, hatch and egress geometry, alarm logic that integrates with mobility assets, and acceptance tests tied to life-support performance. The aim is practical: a minimum, testable rule set that lets different contractors deliver interoperable modules and gives crews a consistent safety envelope regardless of who built the hardware.

A realistic path to “version 1”

The most credible near-term approach is a derivation, not a blank slate: adopt the human-system and material-flammability baselines (NASA-STD-3001 and NASA-STD-6001), add surface-specific clauses for pressure-zone isolation and egress/refuge, and require full-scale fire behaviour validation to close remaining gaps (drawing directly on Saffire data). Habitat layout research developed for Artemis provides the template for how those clauses map to internal architecture. That combination yields a code engineers can design to, programme offices can certify against and, crucially, crews and insurers can understand.

The value of such a standard is operational rather than rhetorical. It turns “habitat” from concept art into a serviceable, inspectable asset with known failure modes and recovery options. In a setting where “outside” is vacuum and fire is chemistry accelerated by oxygen, the line between a viable lunar presence and an experiment lies in these details being written down, tested and shared.