Residential Addition: 20 Issues Including Critical Structural & Life Safety Violations
A comprehensive plan review of a residential addition project uncovered 20 issues including critical structural under-design, missing emergency escape openings, egress violations, and code compliance errors—before permit submission.
The Project
A residential addition project at 918 Blackwell Court, Marietta, Georgia. InspectMind performed a comprehensive plan review of the architectural and structural drawings, identifying critical structural under-design (30 PSF for decks requiring 40 PSF), missing emergency escape openings in basement, missing means of egress for western living area, and extensive code compliance errors before permit submission.
Critical Findings (5)
Sheet S-1, Note 2 specifies a design live load of 30 PSF for 'RESIDENTIAL SLEEPING AREAS.' However, the sheet is the 'FLOOR FRAMING LAYOUT' for the entire first floor and includes framing for exterior decks (e.g., 2" x 12" and 2" x 8" joists). Per IBC Section 1607.1, structural members must be designed to resist the live loads appropriate for their use. For Residential Group R-3 occupancies (Section 310.4), standard areas and exterior decks require a minimum live load of 40 PSF. Designating the entire framing layout, including decks, as 'Sleeping Areas' at 30 PSF results in significant structural under-design.
Code: 2024 International Building Code
The building elevations on Sheet A-6 show a basement level (foundation level) with a height of 13'-9" between the subfloor and the floor above. IBC Section 1031.2 requires basements to have at least one emergency escape and rescue opening (EERO). The elevations for all four sides (Front, Rear, Left, and Right) show the foundation level, but no compliant windows or swinging doors are depicted at this level. The garage doors shown on the Front Elevation do not satisfy the requirements of Section 1031.3 for escape and rescue openings as they are not side-hinged doors or windows.
Code: 2024 International Building Code
The 'PROPOSED FIRST FLOOR LAYOUT' shows a solid interior partition wall dividing the building footprint. The western zone of the 'LIVING AREA' (approximately 728 sq. ft.) contains no exterior doors and no opening is depicted in the partition wall leading to the eastern zone where the primary exit door is located. IBC Section 1006.2 requires all rooms and spaces to be provided with access to exits.
Code: 2024 International Building Code
The drawing shows a 3'0" wide door (tagged '3068') swinging into a landing/passage area that is dimensioned as only '2'' (24 inches) deep before reaching the stair run. IBC 1010.1.1 requires the clear opening width of 32 inches to be measured with the door open 90 degrees. A 36-inch door cannot open 90 degrees within a 24-inch deep space, as it would strike the stairway/opposite wall at approximately 42 degrees.
Code: 2024 International Building Code
The cover sheet contains conflicting project addresses. The title block area in screenshot 01 shows the project address as '9118 BLACKWELL CT.' while the project description in screenshot 02 shows '918 BLACKWELL CT.' This is a clear inconsistency that creates ambiguity about the actual project location.
Sample High Priority Findings (11 Total)
The drawing specifies '4X4 STEEL POST HSS' at six locations on the floor framing plan without indicating the wall thickness. Per IBC Section 2201.2, identification of steel members shall be in accordance with applicable referenced standards. Per Section 2202.1, structural steel elements shall be in accordance with AISC 360. HSS (Hollow Structural Section) designations per AISC 360 and ASTM A500 require the wall thickness as part of the complete designation (e.g., 'HSS 4x4x1/4' or 'HSS 4x4x3/16'). The designation '4X4 STEEL POST HSS' omits this required parameter, meaning the identification does not conform to the applicable referenced standards as required by the code.
Code: 2024 International Building Code
The elevations (specifically Elevation 4 on Sheet A-6) show the exterior stair handrails and the landing guards as a single continuous assembly where the top rail serves both functions at a uniform height. According to IBC Section 1014.2, handrail height must be between 34 and 38 inches. However, Section 1015.3 requires guards to be at least 42 inches high. It is physically impossible for a single top rail to satisfy both requirements simultaneously as the maximum handrail height (38") is lower than the minimum guard height (42").
Code: 2024 International Building Code
The 'PROPOSED SECOND FLOOR LAYOUT' shows an exterior stairway on the south side of the building labeled 'DN' (down) with a dimension of 2' (24 inches) spanning its width. According to IBC Section 1011.2, Exception 1, stairways serving an occupant load of less than 50 (this residential floor is 1,598 sq ft, resulting in approximately 8 occupants per Table 1004.5) must have a minimum width of 36 inches.
Code: 2024 International Building Code
The western zone of the living area measures 28' x 26', totaling 728 sq. ft. According to IBC Section 1204.2, the minimum net glazed area must be at least 8% of the floor area, which is 58.24 sq. ft. The drawings only show two '3050DH' windows in this zone, providing a total nominal glazed area of 30 sq. ft., which is only 4.1% of the floor area. The '3050FX' window is located outside this zone.
Code: 2024 International Building Code
The site plan contains conflicting information about building and deck areas. The plan view labels the existing residence as '1430 sq. ft.' while the site data table lists 'EXISTING 2 STORY HOUSE: 1,550 SQ.FT.' - a 120 sq.ft. discrepancy. Additionally, Deck 1 is dimensioned as 16'X12' (192 sq.ft.) on the plan, but the site data table shows 'DECK 1: 224 SQ.FT.' - a 32 sq.ft. discrepancy. These conflicts violate Section 107.2.1 which requires construction documents to be 'of sufficient clarity to indicate the location, nature and extent of the work proposed.'
Code: 2024 International Building Code
The Site Plan (S-2) illustrates the residence and deck footprints within the property boundaries but fails to provide numerical dimensions for the distances from these structures to the property lines (lot lines). IBC Section 107.2.6 explicitly requires the site plan to show distances from lot lines.
Code: 2024 International Building Code
The General Notes (screenshot 04.png) cite the 'INTERNATIONAL BUILDING CODE - 2018 EDITION' and 'INTERNATIONAL RESIDENTIAL CODE... 2018 EDITION' as the governing construction codes. This contradicts the project's ground truth requirement to comply with the 2024 International Building Code.
Code: 2024 International Building Code
The project address is located in Marietta, GA (screenshot 01.png), which is situated in Cobb County. However, General Note 1 (screenshot 05.png) incorrectly states that all means and methods of construction must conform to the regulations of 'FULTON COUNTY'. This is a direct contradiction of the jurisdictional authority defined in the building code.
Code: 2024 International Building Code
The drawing contains conflicting information regarding the project address. Sheet A-1 (screenshot 01.png) identifies the address as '9118 BLACKWELL CT.', while subsequent sections on the same sheet (screenshot 02.png) list it as '918 Blackwell Ct.' and '918 BLACKWELL CT' multiple times. This violates the requirement for construction documents to be of sufficient clarity regarding the location of the work.
Code: 2024 International Building Code
The drawing's General Notes for Foundation Walls specify a design lateral soil pressure of 30 psf/ft. However, the IBC requires foundation walls that are restricted at the top to be designed for 'at-rest' pressure. According to Table 1610.1, the minimum at-rest pressure for any backfill material is 60 psf/ft (for GW, GP, SW, and SP soils), which is double what is specified in the drawing.
Code: 2024 International Building Code
Issue Categories
Life Safety
Emergency escape and rescue openings, means of egress, egress requirements, and life safety code compliance
Structural
Live load design, foundation walls, structural member identification, and structural code compliance
Code Compliance
Building code violations, code edition conflicts, jurisdictional requirements, and compliance issues
Document Coordination
Drawing conflicts, address discrepancies, area calculation conflicts, and document coordination issues
Architectural
Door clearances, stairway widths, natural light requirements, and architectural code compliance
Value Delivered
"The structural under-design of the decks and the missing emergency escape opening in the basement would have been instant permit rejections. Finding 20 issues—including 5 critical structural and life safety violations—before submission saved us from weeks of redesign and potential safety failures."
— Project Team, Residential Addition