Every year, construction and demolition sites across Calgary generate thousands of tonnes of debris, dust, and construction materials. While the majority of this material remains safely managed within the project boundaries, the risk of objects being inadvertently projected onto public ways-sidewalks, roads, and neighboring properties-cannot be overstated. These risks can result in serious injury, property damage, and costly liability for everyone involved in a project: homeowners, builders, and developers alike.

Understanding NBC OS5.1: The Foundation of Public Safety

The National Building Code (NBC) sets a strong foundation for construction safety in Canada, and Objective OS5.1 stands as a critical pillar in protecting the public adjacent to construction and demolition sites. Specifically, NBC OS5.1 addresses “injury caused by impact with objects projected onto public ways.” This includes any material-ranging from hand tools to fragments of wall, or windborne debris-that could be thrown, dropped, or blown from a work site.

Violation of this code is not just a regulatory issue: it’s a matter of public trust, community safety, and professional due diligence. Failure to prevent objects from leaving the work zone can result in:

  • Serious injury or fatality to pedestrians and vehicle occupants
  • Legal actions and insurance claims against property owners, contractors, and developers
  • Significant construction delays due to investigations or ordered work stoppages
  • Damage to community reputation and loss of future business prospects

Scope of NBC OS5.1

The objective is explicitly designed to address risk “in past or present constructed areas around the building,” focusing especially on adjacent public ways. Hazards considered include, but are not limited to:

  • Falling tools, loose hardware, or small modules
  • Chunks of facade, glass, or structural components
  • Debris ejected or carried by wind
  • Heavier equipment or machinery parts in case of failure
  • Contaminants, such as dust or chemical spray, that could irritate or harm the public

Calgary’s Regulatory Framework: Local Rules and Reinforced Standards

While the NBC sets national standards, Calgary’s local regulations further reinforce public safety, integrating these codes directly into permitting procedures and construction site expectations. The City of Calgary, acknowledging the unique climate and density of its urban core, has created a robust suite of bylaws and administrative requirements that address projected object hazards holistically.

Public Protection Site Safety Plans (PPSSP)

For all projects involving buildings five storeys or taller-or those classified as “high buildings” under the Alberta Building Code-the City of Calgary requires developers to submit a Public Protection Site Safety Plan (PPSSP) prior to permit approval. This plan must include:

  • Detailed mapping of the construction site perimeter and adjacent public spaces
  • Specifications for temporary fencing, hoarding, barricades, and covered walkways
  • Description of netting, scaffolding protection systems, and work zone signage
  • Procedures for debris containment and daily site cleaning
  • Emergency response procedures addressing both routine and exceptional events

The PPSSP is not a static document: it evolves throughout the project lifecycle. Site supervisors and safety officers must regularly review and update the plan as conditions change, ensuring that new risks are proactively managed.

Construction Site Hoarding and Fencing

Regulations require that all active construction and demolition sites in Calgary employ robust hoarding and fencing systems. The intent is multifold:

  • Prevent all unauthorized access by the public, including children, pets, and vandal-prone individuals
  • Contain construction debris generated by daily activities or caused by environmental factors (wind, rain, snow)
  • Serve as a visual and physical deterrent, warning the public of the potential hazards beyond the barrier

Effective hoarding systems are typically constructed from heavy-duty plywood or metal panels, anchored on secure frames, and must be high enough (often 2.44 meters/8 feet or higher) to resist climbing and wind loading. Covers, gates, and access points should be continuously locked outside of supervised working hours.

Advanced Weather Forecasting System (AWFS)

Calgary’s weather can change quickly, especially with high winds and sudden storms. Buildings constructed at greater heights are particularly susceptible to unexpected wind gusts, which can transform loose materials or equipment into dangerous projectiles.

To address this, the City of Calgary mandates the use of an Advanced Weather Forecasting System (AWFS) for high-rise construction projects. The AWFS:

  • Provides real-time and forecasted data on gusts, temperature shifts, and precipitation
  • Issues alerts ahead of severe weather, allowing site managers to secure or remove loose items
  • Informs decisions to adjust work schedules or implement heightened safety protocols

The use of AWFS has proven critical in minimizing incidents where objects are blown or projected onto public ways, particularly given Calgary’s history of sudden, severe Chinook winds.

Demolition and Excavation Permits in Calgary: Ensuring Compliance

Obtaining the correct permits is the first, non-negotiable step in any demolition or excavation process. For both small residential teardowns and large-scale commercial redevelopments, the City of Calgary requires rigorous documentation, complete with explicit provisions addressing NBC OS5.1 compliance.

Demolition Permit

Any project involving the demolition (or relocation) of a building in Calgary-residential or commercial-requires issuance of a Demolition Permit. The application process includes submitting:

  • Detailed demolition plans, including timeframes
  • Descriptions and diagrams of the methods used for public protection (hoarding, debris netting, dust suppression)
  • PPSSP when applicable
  • Notification to utility providers for safe disconnection
  • Contact details for the site supervisor responsible for safety

Fee structure: The base rate for a demolition permit is $1.44 per square meter of building area, subject to minimum and maximum fees. There is also a mandatory administration fee of $112.00. Costs may vary depending on the specific characteristics of the building, its location, and the anticipated complexity of public safety management. (calgary.ca)

Excavation Permit

Any time excavation works take place within the public road right-of-way, an Excavation Permit is needed. This includes trenching for utilities, underpinning foundations, or installing drainage systems near streets and sidewalks. Responsibilities include:

  • Restoration of road and sidewalk infrastructure post-work
  • Continuous management of site hazards affecting the public or adjacent properties
  • Implementation of durable fencing, signage, ramps, and other access control measures

Fees include:

  • Application fee: $75.00
  • Works inspection fee: $120.75
  • Additional charges based on road types and area size

Application forms must demonstrate how the work will conform to the requirements of NBC OS5.1 and City bylaws. (calgary.ca)

Permission to Permit Program

For larger-scale or multi-phase projects, Calgary’s “Permission to Permit” program allows contractors to pre-pay certain pavement degradation and restoration fees at a flat rate based on project parameters. This streamlines budgeting, reduces administrative complexity, and allows project teams to plan with greater financial certainty. The program is ideal for developers anticipating multiple excavations on a large site.

Timelines for Permit Approval

Prompt processing of permits is achievable when documentation is thorough and compliant from the outset:

  • Demolition Permit: Processed in approximately 7 days, barring document deficiencies
  • Excavation Permit: Processed within 2 business days, or up to 10 business days if roads resurfaced within the last two years are involved

Applicants should proactively consult with the City’s Planning & Development team and anticipate possible questions about safety measures regarding projectiles and barrier integrity.

Practical, Effective Site Safety Against Projected Objects

The most robust plans and regulatory approvals are only as effective as their on-the-ground application. For CBC OS5.1 and municipal codes to deliver true safety, developers and builders must translate paperwork into actionable, daily routines. The following are best practices for safeguarding public ways from projectiles at every stage of demolition or excavation.

Barrier Systems: Hoarding, Fencing, and Covered Walkways

  • Hoarding: Constructed ideally from 16mm (5/8") thick plywood, treated for weather exposure, and installed on a steel or timber frame. Height must align with city code and be high enough to prevent climbing or reaching over.
  • Fencing: Heavy-duty chain-link or steel fencing is suitable for lower-risk perimeters or non-urban settings but must be supplemented with netting or solid panels where there is a higher risk of falling or windborne debris.
  • Covered walkways (Pedestrian Tunnels): In areas where pedestrians must pass nearby, especially on high-density streets, covered walkways constructed with heavy timber or steel and durable sheathing are essential to protect users from falling materials.

Regular inspection (daily, at a minimum) and immediate repair of any damage or moved components is critical. Leaving gaps or weakened sections, even for a few hours, exposes the public and the project to risk and liability.

Debris Netting and Protective Screening

For structures above two storeys, or where demolition is occurring at height, the addition of debris netting is increasingly recognized as an essential measure. Generally made from fine, tear-resistant mesh capable of catching both large and small objects, netting should be:

  • Installed tightly along building perimeters and between scaffolding elements
  • Routinely checked for rips, tears, or stress failures after windy conditions or heavy work
  • Supplemented with additional layers in high-traffic zones or above entrances/exits

Material and Tool Management

  • Secure storage: All materials not actively in use should be tethered, weighted down, or locked within site trailers/lockers.
  • Tool lanyards: Hand tools or equipment used at height should be secured with lanyards or cords to prevent accidental dropping.
  • Housekeeping: Site crews must adhere to end-of-day walk-around routines to remove or secure items that could be carried by wind or inadvertently knocked outside barriers.

Material deliveries should be scheduled during low-traffic hours, and delivery personnel must be briefed on on-site restrictions relating to public corridors and adjacent property lines.

Responding to Weather Events

Calgary’s sudden weather shifts-including wind gusts exceeding 80 km/h-pose a specific, documented hazard according to city data. The AWFS (Advanced Weather Forecasting System) provides several hours’ to days’ notice of such events, giving project supervisors time to:

  • Postpone non-essential work, particularly with cranes or at heights
  • Double-check the integrity of fencing, netting, and covered walkways
  • Remove or secure signage, waste bins, loose timber, and scaffolding planks

Daily Inspections and Site Supervision

Dedicated safety officers should carry out at least one, preferably two, perimeter walkarounds daily-morning and before close. Inspections must be documented and deficiencies corrected before work resumes. Any “near miss” (incident where an object came close to leaving the site) must be recorded, reviewed, and prompt corrective action implemented.

Engaging the Public: Communication as a Safety Tool

The perception of safety is as important to public trust as the physical measures themselves. Maintaining ongoing, open communication with neighbors, tenants, local businesses, and city officials builds support for the project, keeps people informed, and can reduce the spread of misinformation or fear.

Effective Communication Practices

  • Advance written notice to local businesses and residents before demolition or large excavation begins, detailing timelines, potential disruptions, and safety measures
  • Clearly posted contact information for site safety supervisors and project managers at entrances and hoarding sections
  • Rapid notification of unscheduled changes-such as emergency work or heightened safety precautions due to weather
  • Public information sessions or Q&A opportunities for larger, long-term developments

Being accessible, available, and responsive decreases complaint volumes and legal exposure in the event of a safety incident.

Fire Safety and Emergency Response at Construction Sites

Projected objects are only one aspect of risk at a demolition or excavation site. The National Fire Code (Alberta Edition), as enforced in Calgary, requires every construction project to implement a comprehensive fire safety plan. Overlapping risks-such as sparks igniting debris, or fires that could propel burning materials over barriers-must be anticipated in:

  • Waste disposal and daily site cleaning procedures
  • Storage of flammable materials away from perimeter barriers
  • Locations for fire extinguishers and access routes for emergency responders
  • Evacuation procedures for both workers and adjacent public spaces

Compliance requires both upfront planning and routine, practical drills for worker teams. The plan should be included in the PPSSP for larger or high-rise projects, or as a standalone document for smaller developments and residential demolitions. (calgary.ca)

Builders and Developers: Due Diligence and Legal Liability

It’s important for all project stakeholders to realize that failing to prevent objects from being projected onto public ways isn’t merely a code violation-it creates direct liability.

  • Owners, not just contractors, can be sued for damages or injuries
  • Insurance policies may decline claims if proactive safety steps aren’t verifiably documented
  • Even “minor” object ejections, such as windblown insulation or paper, can trigger enforcement action

Furthermore, municipal inspectors can order immediate work stoppages or issue administrative fines if safety conditions are observed to be non-compliant-even when no actual injury has occurred.

Best Practices in Documentation and Recordkeeping

  • Maintain up-to-date copies of all permits, safety plans, and site maps on-site and accessible to supervisors
  • Log all safety inspections and repairs (digital apps are encouraged for easy retrieval)
  • Retain copies of all public and neighbor notifications for the duration of the project and at least two years after completion
  • Ensure training records for all workers on both general and project-specific safety measures

This diligence provides a robust defense against claims or enforcement actions, and demonstrates a culture of care that can enhance reputation and community relationships.

Case Examples: Lessons in Projected Object Prevention

Example 1: Inner-City Infill

A builder working in Calgary’s Hillhurst neighborhood began demolition of an old two-storey residence on a block with heavy pedestrian traffic. On the initial day, high winds caused a section of plywood sheathing to detach and cross the sidewalk. The incident resulted in a complaint to city inspectors, followed by a complete work shutdown order until a more robust hoarding system, tied to ground anchors and supplemented by 10’ debris netting, was implemented. With this upgrade, the project finished safely and on schedule.

Example 2: High-Rise Redevelopment

During excavation for a downtown high-rise tower, a passing Chinook wind event created dangerous downdrafts around a partially completed scaffolding structure. The AWFS issued timely warnings, and the builder, having invested in training and site management, halted all above-ground work, securing equipment and loose debris. No objects were lost in the event, and City inspectors commended the team for their proactive use of technology and strong barrier systems.

Example 3: Residential Subdivision Excavation

A developer excavating for a new residential block fell behind on implementing daily cleaning routines. Unsecured polystyrene insulation pieces, meant for below-grade installation, escaped through temporary fencing after a storm. Complaints from neighbors prompted a fine and additional site review. Once new daily jobsite housekeeping and end-of-day barrier checks were adopted, there were no further violations.

Integrating NBC OS5.1 into Every Phase: A Project Lifecycle Guide

Pre-Construction

  • Careful review of adjacent public ways and population density
  • Preparation of a PPSSP or at least a documented safety strategy
  • Advance coordination with city regulatory officials and utility providers
  • Selection of qualified, safety-trained demolition and excavation sub-contractors

Active Demolition/Excavation

  • Full installation of hoarding, fencing, and netting before any building portions are deconstructed
  • Frequent checks of all barriers and project boundaries
  • Monitoring AWFS data and weather forecasts
  • Enforcement of material storage and tool tie-off procedures

Post-Demolition/Excavation

  • Complete cleaning and debris removal within project lines-nothing left for wind or ice to pick up
  • Inspection and repair of any impacts to sidewalk or roads, including prompt reporting to the City
  • Restoration of any street furniture, signage, or landscaping disturbed during the project

Close-Out and Handover

  • Removal of barriers only when no further risk of object projection exists
  • Final inspection by city officials and signed-off documentation retained as record
  • Feedback session with all workers and supervisors for lessons learned and continuous improvement

Common Challenges and How to Overcome Them

Challenge 1: Urban Space Constraints

Tight Calgary urban work sites pose particular challenges: there is little room for setback, and hoarding often borders directly on walkways or busy roads. In these scenarios:

  • Opt for higher, heavier, and more continuous hoarding-using steel and “pedestrian tunnels” where feasible
  • Employ redundant systems: combine fencing with inner debris netting and frequent cleaning
  • Consider off-hours or phased demolition to minimize risk during high-traffic periods

Challenge 2: Renovation and Partial Deconstruction

Partial “gut jobs” or renovations are not immune from NBC OS5.1 requirements. Removing windows, balconies, or masonry can release loose material. Even if only one or two sides of the building are being altered, full hoarding on exposed perimeters is vital.

Challenge 3: Subcontractor and Worker Training

If any party working on site (including outside delivery drivers or temporary laborers) isn’t trained on projectile safety rules, compliance gaps will result. Hold mandatory orientations and regular “toolbox talks” to remind everyone of SOPs for barrier maintenance, material handling, and emergency procedures.

Challenge 4: Weather and Unforeseen Events

  • Have pre-written emergency checklists integrated into supervisor roles for all types of severe weather
  • Ensure backup hoarding, netting supplies, and repair crews are ready at short notice

Fostering a Site Culture of Safety

Permits, plans, and barriers are not a substitute for a collective commitment to public safety from everyone on site. Leadership from site supervisors is key, but so is empowering laborers and sub-trades to “stop the line” and report issues before they escalate. Tools for fostering this culture include:

  • Hazard identification boards at worker entry points
  • Encouraging anonymous hazard reporting (either digitally or on-site)
  • Incident debriefs and sharing root causes across teams
  • Recognition or small rewards for proactive safety actions

By treating the risk of objects projected onto public ways as a shared concern, every participant-from project manager to the newest laborer-becomes part of a culture that values prevention above all.

Conclusion: Protecting Calgary’s Public Starts Here

Responsible, code-compliant demolition and excavation work in Calgary means understanding that every plank, brick, piece of drywall, or tool must remain within your control at all times. NBC OS5.1, together with Calgary’s local requirements on PPSSP, hoarding, fencing, and weather monitoring, forms an integrated framework that sets the bar for public safety-and demands ongoing commitment throughout every phase of your project.

Whether you’re a homeowner overseeing a single-family tear-down, a custom home builder breaking ground on infill, or a developer planning the next major transformation in the downtown core, upholding the highest standards against projected object hazards is essential to safeguarding everyone’s well-being and to the long-term success of your project.

Comprehensive planning, diligent permit compliance, robust physical defenses, and a culture of safety are the best tools in ensuring no object-large or small-crosses into Calgary’s vibrant public spaces unsafely.

For help navigating demolition and excavation safely, turn to the licensed experts at Kingsway Demolition & Excavation.