Structure Demolition AHA (Activity Hazard Analysis / Job Hazard Analysis)
Updated 2026-06-23
A Structure Demolition AHA (Activity Hazard Analysis / Job Hazard Analysis) is the plan that keeps the crew performing structure demolition safe from structural collapse and sequence failures, from the pre-demolition survey and hazardous materials, and from the demolition equipment and falling debris. Structure demolition demolishes structures in a controlled sequence — combining the structural-collapse and sequence hazard, the pre-demolition-survey and hazardous-materials hazard, and the demolition-equipment and debris/falling-material hazard. This guide walks through building a Structure Demolition AHA that names the structural-collapse/sequence, pre-demolition-survey/hazardous-materials, and demolition-equipment/debris hazards and assigns the collapse, survey, and equipment controls that hold up in the field.
Why structure demolition needs its own AHA
Structure demolition is the controlled demolition of structures — bridges, towers, tanks, industrial structures, and other built structures — bringing them down in a planned, controlled manner using mechanical demolition, dismantling, or other methods. The defining feature is the controlled collapse: demolition is intentional structural failure, so the sequence and control of that failure are the central safety concern, along with the pre-demolition survey (hazardous materials, structure) and the equipment and falling debris. The hazards combine the structural-collapse and sequence (demolition is intentional, controlled structural failure — the hazard of uncontrolled/premature/unplanned collapse (the structure coming down in an unintended way), requiring an engineered demolition sequence), the pre-demolition-survey and hazardous-materials (demolition requires a pre- demolition engineering survey (the structure's condition, stability, and demolition method) and a hazardous- materials survey (asbestos, lead, PCBs must be identified/abated before demolition disturbs them)), the demolition-equipment and debris/falling-material (the demolition equipment (excavators, shears, breakers, wrecking) and the falling debris/material — the equipment, struck-by, and falling-material hazards), and the dust/stability- of-workers. The structural-collapse/sequence and the pre-demolition-survey/hazardous-materials justify a dedicated AHA.
Breaking structure demolition into steps
The steps for a Structure Demolition AHA follow the demolition:
- Perform the pre-demolition engineering and hazmat surveys
- Abate hazardous materials before demolition
- Plan the engineered demolition sequence
- Isolate utilities and establish exclusion zones
- Demolish in the controlled sequence
- Manage the collapse, equipment, and debris hazards
- Process and remove the debris
- Complete
Each step carries a hazard, and the structural-collapse/sequence, the pre-demolition-survey/hazardous-materials, and the demolition-equipment/debris are where the most significant risks concentrate.
The hazards step by step
Structural-collapse and sequence
Demolition is intentional, controlled structural failure — the hazard of uncontrolled/premature/unplanned collapse (the structure coming down in an unintended way), requiring an engineered demolition sequence. The controls are an engineered demolition plan and sequence (a competent/qualified person's plan for how the structure comes down safely — sequence, methods, stability at each stage), maintaining stability through the demolition (not undermining/removing elements out of sequence), exclusion zones for the collapse (no one in the collapse/drop zone), monitoring for unplanned movement, and the collapse/sequence controls. The structural- collapse/sequence is the primary defining hazard — demolition is controlled collapse, so the sequence is the safety. (These follow the demolition-engineering fundamentals.)
Pre-demolition-survey and hazardous-materials
Demolition requires a pre-demolition engineering survey (the structure's condition, stability, and demolition method) and a hazardous-materials survey (asbestos, lead, PCBs must be identified/abated before demolition disturbs them). The controls are the pre-demolition engineering survey (a competent person assessing the structure before demolition — condition, stability, method), the hazardous-materials survey and abatement before demolition (demolition disturbs any asbestos, lead, or PCBs — these must be identified and abated first), and the survey/hazmat controls. The pre-demolition-survey/hazardous-materials is a defining hazard — the surveys are required before demolition. (These follow the demolition-survey fundamentals.)
Demolition-equipment and debris/falling-material
The demolition equipment (excavators, shears, breakers, wrecking) and the falling debris/material — the equipment, struck-by, and falling-material hazards. The controls are mobile-equipment safety (exclusion zones, separation, equipment rated for demolition with operator protection), controlling the falling debris/material, struck-by protection, and the equipment/debris controls. The demolition-equipment/debris is a defining hazard. (These follow the demolition-equipment fundamentals.)
Dust/stability-of-workers
The dust and worker-stability (demolition dust including silica; worker positions on/near the structure) carries the dust/position hazard. The controls are dust control (wet methods for silica), safe worker positions (fall protection, not on unstable structure being demolished), and the dust/position controls. (These follow the silica and fall-protection fundamentals.)
A simple Structure Demolition AHA structure
| Step | Hazard | Control | Standard |
|---|---|---|---|
| Survey | Condition / hazmat | Pre-demolition engineering and hazmat surveys | OSHA 1926.850 |
| Abate | Hazardous materials | Abate asbestos/lead/PCBs before demolition | OSHA 1926.1101 |
| Plan | Collapse | Plan engineered demolition sequence | OSHA 1926.850 |
| Isolate | Utility / collapse | Isolate utilities, establish exclusion zones | OSHA 1926.850 |
| Demolish | Uncontrolled collapse | Demolish in controlled sequence, maintain stability | project |
| Remove debris | Struck-by / dust | Process/remove debris, dust control | OSHA 1926.1153 |
Engineered-sequence collapse control and pre-demolition survey
A Structure Demolition AHA centers on engineered-sequence collapse control and the pre-demolition survey. The engineered-sequence collapse control addresses demolition as controlled structural failure — controlled by an engineered demolition plan and sequence (how the structure comes down safely), maintaining stability through the demolition, exclusion zones for the collapse (no one in the drop zone), and monitoring for unplanned movement. The pre-demolition survey addresses the required surveys — controlled by the pre-demolition engineering survey (a competent person assessing the structure's condition, stability, and method) and the hazardous-materials survey and abatement before demolition (asbestos, lead, PCBs identified and abated first). And the equipment and debris get mobile-equipment and struck-by controls. An AHA built on engineered-sequence collapse control and the pre-demolition survey, with equipment controls, addresses the hazards that define structure demolition.
From the field: what actually goes wrong
In fourteen years across federal, heavy civil, and industrial projects, structure demolition is intentional, controlled structural failure — and the entire safety of it rests on that failure being controlled, which is why the engineered sequence and the pre-demolition surveys are the defining concerns. The structural-collapse and sequence hazard is the primary defining concern — demolition means deliberately causing a structure to fail and come down, so the central hazard is an uncontrolled, premature, or unplanned collapse (the structure coming down in a way, place, or time that was not intended, which can bury workers and equipment). The control is the engineered demolition sequence: a competent and qualified person's plan for exactly how the structure comes down safely — the sequence, the methods, and the stability at each stage — because a structure being demolished must remain stable and predictable at every step until it comes down where and when intended. So maintaining stability through the demolition (not undermining or removing elements out of sequence), exclusion zones for the collapse (absolutely no one in the collapse or drop zone), and monitoring for unplanned movement are the controls. Demolition is controlled collapse, so the whole game is keeping the collapse controlled.
The pre-demolition-survey/hazardous-materials and the demolition-equipment/debris are the other defining hazards. On the projects I have run, structure demolition requires two pre-demolition surveys, both required by the demolition standard: a pre-demolition engineering survey (a competent person assessing the structure's condition, stability, and the demolition method before work starts — you cannot safely demolish a structure you have not assessed), and a hazardous-materials survey with abatement before demolition (because demolition will disturb any asbestos, lead, or PCBs in the structure, these must be identified and abated first — this is where the assessment cluster from the previous batch directly feeds in). Demolishing a structure with unabated asbestos spreads it catastrophically, which is why the hazmat survey and abatement come first. The demolition-equipment and debris/falling-material hazard is the heavy demolition equipment (excavators, shears, breakers) with exclusion zones and operator protection, and the falling debris and material, controlled by mobile-equipment safety, controlling the falling material, and struck-by protection. The dust (including silica) and safe worker positions round it out. The AHA built on engineered-sequence collapse control and the pre-demolition survey is the one that protects the demolition crew.
The bottom line
A Structure Demolition AHA names the structural-collapse/sequence, the pre-demolition-survey/hazardous-materials, and the demolition-equipment/debris hazards with specific controls — an engineered demolition sequence with collapse exclusion zones (demolition is controlled collapse, so the sequence is the safety), pre-demolition engineering and hazmat surveys with abatement before demolition, and mobile-equipment safety with falling-debris control. The engineered-sequence collapse control and the pre-demolition survey are the defining concerns. The AHA that manages both is the one that protects the crew.
Frequently asked questions
Why is the engineered sequence the central safety control?
Demolition means deliberately causing a structure to fail and come down, so the central hazard is an uncontrolled, premature, or unplanned collapse (the structure coming down in a way, place, or time not intended, which can bury workers and equipment) — and a structure being demolished must remain stable and predictable at every step until it comes down where and when intended. Controls are an engineered demolition plan and sequence (a competent/qualified person's plan for how the structure comes down safely — sequence, methods, stability at each stage), maintaining stability through the demolition, exclusion zones for the collapse (no one in the drop zone), monitoring for unplanned movement, and the collapse/sequence controls.
Why are the pre-demolition surveys required?
Structure demolition requires a pre-demolition engineering survey (a competent person assessing the structure's condition, stability, and method before work — you cannot safely demolish a structure you have not assessed) and a hazardous-materials survey with abatement before demolition (demolition disturbs any asbestos, lead, or PCBs, which must be identified and abated first — demolishing with unabated asbestos spreads it catastrophically). Controls are the pre-demolition engineering survey, the hazardous-materials survey and abatement before demolition, and the survey/hazmat controls.
What equipment and debris hazards apply?
The demolition equipment (excavators, shears, breakers, wrecking) and the falling debris/material bring the equipment, struck-by, and falling-material hazards. Controls are mobile-equipment safety (exclusion zones, separation, equipment rated for demolition with operator protection), controlling the falling debris/material, struck-by protection, dust control (wet methods for silica), and the equipment/debris controls.
What is structure demolition?
Structure demolition is the controlled demolition of structures — bridges, towers, tanks, industrial structures, and other built structures — bringing them down in a planned, controlled manner using mechanical demolition, dismantling, or other methods. Because it is controlled structural collapse (sequence), requires pre-demolition engineering and hazmat surveys, and uses heavy equipment with falling debris, those hazards apply.
Related AHAs and JHAs
- Building Demolition AHA — the demolition of buildings
- Tower Demolition AHA — the demolition of towers
- Selective Site Demolition AHA — the selective site demolition
- Demolition Work JHA — the demolition fundamentals
Written by Mustafa Tok, CSP, ASP, CHST — OSHA Authorized Outreach Trainer with 14+ years of international construction safety experience across federal, heavy civil, and industrial projects.