Under AACE RP 18R-97, a Class 3 cost estimate (budget authorization/control or bid-tender level) carries an expected accuracy range of -20% to +30%.

OSHA's respirable crystalline silica in construction standard (29 CFR 1926.1153) sets an action level (AL) of 25 micrograms per cubic meter (µg/m³) as an 8-hour time-weighted average, half the PEL.

OSHA 29 CFR 1926.451(g)(1) requires guardrails, a personal fall-arrest system, or both to protect each employee on a scaffold more than 10 feet (3.1 m) above a lower level from falling.

The AIA A201 General Conditions (Article 15) requires that Claims by either the Owner or Contractor be initiated by written notice within 21 days after occurrence of the event giving rise to the Claim, or within 21 days after the claimant first recognizes the condition giving rise to it, whichever is later.

The AIA A201-2017 revision shortened the notice period for claims related to concealed or unknown (differing) site conditions under Section 3.7.4 from 21 days to 14 days.

OSHA 29 CFR 1926.501(b)(1) requires fall protection (guardrail, safety net, or personal fall arrest system) for each construction employee on a walking/working surface with an unprotected side or edge 6 feet (1.8 m) or more above a lower level.

OSHA 29 CFR 1926.652 requires a protective system (sloping, shoring, or shielding) for any trench excavation 5 feet (1.5 m) deep or greater, unless the excavation is made entirely in stable rock.

OSHA 29 CFR 1926.652(b)-(c) requires that protective systems for trench excavations 20 feet (6.1 m) deep or greater be designed by a registered professional engineer or based on tabulated data approved by one.