10.3 Safeguards During Construction & Protection of Adjacent Property

1. Scope of Safeguards During Construction (IBC Chapter 33)

Chapter 33 governs safety to life and property during construction, alteration and demolition, and much of it is verified at plan review rather than in the field. The plans examiner checks the site safety plan, pedestrian protection, adjacent-property protection, temporary egress and standpipes, and construction-phase water supply before the permit is issued.

General requirements (3301): construction equipment and material storage may not exceed the safe load-carrying capacity of any structure (3301.2); roof loads during construction may not exceed the design capacity (3301.3); required exits, existing structural elements, fire protection devices and sanitary safeguards must be maintained at all times during alterations, repairs or additions (3301.4); and waste materials must be removed in a manner that prevents injury or damage (3301.5).

Owner's responsibility for fire protection (3302): the 2024 IBC requires a site safety plan with defined components, a designated site safety director for the projects it covers, and a daily fire safety inspection verifying items such as maintained egress, standpipes in service to the highest work floor per Section 3311, and portable extinguishers per Section 3309.

2. Demolition and Site Work (IBC 3303, 3304)

Demolition (3303): construction documents and a schedule are required (3303.1); pedestrian protection must be in place before demolition begins (3303.2); required means of egress must be maintained at all times (3303.3); the vacant lot must be graded and maintained free from hazards after demolition (3303.4); water accumulation must be prevented (3303.5); and service utility connections must be discontinued and capped in accordance with the utility rules (3303.6).

Site work (3304): excavation and fill must be executed so it does not endanger adjacent property; slope limits, surcharge restrictions, footings on adjacent slopes, and fill supporting foundations are all addressed in 3304.1.1 through 3304.1.4. Fill supporting foundations must be placed in accordance with Section 1804.

3. Protection of Pedestrians (IBC 3306)

This is the most reliably tested table in Chapter 33. Protection type depends on the height of construction and the distance from the construction to the lot line:

Supporting dimensional rules:

• Walkways (3306.2): not less than 4 feet wide, durable walking surface, accessible per Chapter 11, designed for a live load of not less than 150 psf.
• Construction railings (3306.4): not less than 42 inches high.
• Barriers (3306.5): not less than 8 feet high, placed on the side of the walkway nearest the construction, extending the entire length of the site, with openings protected by doors that are normally kept closed.
• Barrier design (3306.6): designed for Chapter 16 loads, or built prescriptively with 2x4 top and bottom plates and boards not less than 3/4 inch thick or wood structural panels not less than 1/4 inch thick, with stud spacing tied to panel thickness.
• Covered walkways (3306.7): clear height not less than 8 feet, adequate lighting, designed for a live load of not less than 150 psf (a 75-psf exception applies to new light-frame construction not exceeding two stories above grade plane, along with a prescriptive framing recipe).
• Adjacent to excavations (3306.9): every excavation 5 feet or less from the street lot line must be enclosed with a barrier not less than 6 feet high.

4. Adjacent Property, Streets, Extinguishers and Egress

Protection of adjacent property (3307): footings, foundations, party walls, chimneys, skylights and roofs on adjacent public and private property must be protected, water runoff and erosion controlled, and the person causing an excavation must give written notice to adjacent property owners not less than 10 days before the scheduled start. Excavation retention systems must be designed by a registered design professional, monitored for horizontal and vertical movement, and removed only where replacement support exists (3307.2).

Temporary use of streets and public property (3308): materials and equipment may not obstruct fire hydrants, standpipes, fire or police alarm boxes, catch basins or manholes, may not be within 20 feet of a street intersection, and may not obstruct traffic signals or transit loading platforms.

Fire extinguishers (3309): not fewer than one approved portable extinguisher sized for not less than ordinary hazard at each stairway on all floor levels where combustible materials have accumulated, in every storage and construction shed, and additional units where special hazards such as flammable and combustible liquids exist.

Means of egress (3310): where construction exceeds 40 feet in height above the lowest level of fire department vehicle access, a temporary or permanent stairway must be provided and extended to within one floor of the highest point of construction having secured decking. Means of egress and required accessible means of egress must be maintained at all times, unless approved temporary systems are provided.

5. Standpipes, Sprinklers, Water Supply and Fire Watch (IBC 3311 through 3314)

• Standpipes (3311.1): in buildings required to have standpipes by Section 905.3.1, at least one standpipe must be provided for construction use, installed before construction exceeds 40 feet above the lowest level of fire department vehicle access, with hose connections adjacent to the stairways required by 3310.1, and extended to within one floor of the highest point having secured decking. In buildings being demolished, an existing standpipe must be maintained and demolished not more than one floor below the floor being demolished (3311.2).
• Sprinklers (3312): it is unlawful to occupy any portion of a building requiring an automatic sprinkler system until the system has been tested and approved, except under a temporary certificate of occupancy per Section 111.3. Control valves must be checked at the end of each work period when protection is cycled.
• Water supply for fire protection (3313): an approved water supply must be available as soon as combustible building materials arrive on site, on commencement of vertical combustible construction, and on installation of a standpipe. Key numbers: a minimum fire flow of 500 gpm with a hydrant within 500 feet of the combustible materials (3313.2); for Type III, IV and V vertical construction, 500 gpm or the full required fire flow, whichever is greater, where fire separation distance is less than 30 feet; 500 gpm or 50 percent of the required fire flow, whichever is greater, at 30 feet up to 60 feet; and 500 gpm at 60 feet or greater (3313.3.1 through 3313.3.3). Where a standpipe is required, a 500-gpm supply with a hydrant within 100 feet of the fire department connection is required regardless of construction type (3313.5).
• Fire watch (3314.1): required during nonworking hours for construction exceeding 40 feet in height above the lowest adjacent grade at any point along the building perimeter, for new multistory construction with an aggregate area exceeding 50,000 square feet per story, or as required by the fire code official.

6. Plan Review Scenario: Downtown Infill Project

Submittal: a six-story, 85-foot-tall Type IIIA mixed-use building on a zero-lot-line urban site. The building is 3 feet from the front lot line and the sidewalk is directly adjacent. The site plan shows a 3-foot-wide temporary walkway with no canopy, an excavation 4 feet from the street lot line, and no construction-phase standpipe.

Examiner findings:

1. Pedestrian protection. Construction more than 8 feet tall with a lot-line distance of less than 5 feet requires a barrier and covered walkway (Table 3306.1).
2. Walkway width and loading. The walkway must be at least 4 feet wide, accessible, and designed for 150 psf; the covered walkway needs 8 feet clear height (3306.2, 3306.7).
3. Barrier height. Provide an 8-foot-high barrier on the construction side of the walkway (3306.5), plus a 6-foot barrier enclosing the excavation within 5 feet of the street lot line (3306.9).
4. Adjacent owner notice. Provide written notice to adjacent property owners at least 10 days before excavation (3307.1) and a retention system designed by a registered design professional (3307.2.1).
5. Temporary stairway and standpipe. At 85 feet the project exceeds 40 feet, so both a temporary stairway (3310.1) and a construction standpipe installed before exceeding 40 feet (3311.1) are required, with a 500-gpm supply and a hydrant within 100 feet of the FDC (3313.5).
6. Fire watch. Nonworking-hour fire watch applies because construction exceeds 40 feet in height (3314.1).

7. Common Plan Review and Exam Traps

• Trap 1: Reading Table 3306.1 backward. The greater the setback relative to construction height, the less protection is required.
• Trap 2: Using 42 inches for barriers. 42 inches is the construction railing; barriers are 8 feet, and excavation barriers are 6 feet.
• Trap 3: Forgetting the 40-foot trigger. It drives temporary stairways, construction standpipes and the fire watch.
• Trap 4: Treating water supply as a field issue. The 500-gpm/500-foot hydrant rule applies as soon as combustible materials arrive on site.
• Trap 5: Overlooking maintained egress. Existing means of egress must be maintained during alterations unless approved temporary egress is provided (3310.2).