Low. Due to the need for structural calculations, specialized trades (electrical, plumbing), and complex permitting processes, professional design and contractor services are strongly recommended.
Involves multiple disciplines including structural, electrical, plumbing, and building envelope, requiring professional design and adherence to specific DuPage County climate considerations like frost depth and energy efficiency. Moderate complexity due to integration with existing structure and multiple trade inspections.
Project Guidelines & Rules
General Requirements & Permitting
4 Rules
Permit Application
Your local municipality will require a building permit application, detailed construction drawings, and possibly engineering calculations for structural elements.
Site Plan
A detailed site plan showing property lines, existing structures, and the proposed bump-out, indicating setbacks and impervious surface changes, will be required by the local building department.
Design Professional
Structural drawings and calculations sealed by an Illinois-licensed architect or structural engineer are typically required for all new foundations and significant structural modifications. (IRC R106.1)
Construction Documents
Construction documents must clearly delineate compliance with the 2024 IRC, 2023 NEC, and the Illinois Plumbing Code.
Structural Requirements
7 Rules
Foundation Frost Depth
All footings must extend a minimum of 42 inches below finished grade to protect against frost heave, applicable throughout DuPage County. (IRC R403.1.4.1)
Foundation Design
Foundations (e.g., footings, piers, stem walls) must be designed to support all live and dead loads, and lateral forces, based on prevailing soil conditions. (IRC R403.1)
Soil Bearing Capacity
Foundations shall be placed on undisturbed soil or engineered fill with a minimum allowable soil bearing pressure as determined by a soil investigation or IRC Table R401.4.1.
Floor Framing
Floor joists and beams shall be sized according to IRC Table R502.3.1(1) or R502.3.1(2) based on span, spacing, and design loads. Connections must be adequately fastened. (IRC R502)
Wall Framing
Wall studs, headers, and blocking shall be sized and installed according to IRC Chapter 6 for load-bearing and non-load-bearing applications, considering wind loads (e.g., 115 mph V_ult for DuPage County). (IRC R602, R301.2.1)
Roof Framing
Roof rafters or trusses shall be sized and braced according to IRC Chapter 8, considering DuPage County snow loads (minimum 30 PSF ground snow load) and wind loads. (IRC R802, R301.2.1)
Existing Structure Integration
Connections between the new bump-out and the existing structure must be engineered to properly transfer loads and prevent differential settlement or moisture intrusion. (IRC R301.1, R502.6)
Envelope & Weatherproofing
6 Rules
Roofing
Roofing materials and installation shall comply with IRC Chapter 9, matched to existing roofing or an approved equivalent, including proper underlayment and flashing. (IRC R905)
Wall Sheathing
Exterior wall sheathing shall be installed as per IRC R602.10 or R602.11, providing structural rigidity and a substrate for the weather-resistive barrier.
Weather-Resistive Barrier (WRB)
Exterior walls shall be provided with a continuous weather-resistive barrier, such as house wrap or equivalent, installed over the sheathing with proper overlaps and penetrations sealed. (IRC R703.2)
Exterior Finishes
Siding, trim, and other exterior finishes shall be installed according to IRC Chapter 7 and manufacturers' specifications, ensuring proper flashing and water management at all transitions. (IRC R703)
Flashing
All openings (windows, doors) and penetrations shall have proper flashing to prevent water intrusion into the wall assembly. (IRC R703.4)
Fenestration (Windows/Doors)
Windows and doors shall be rated for DuPage County climate zone 5A, properly installed, and flashed to prevent water intrusion. Energy performance must meet IRC Chapter 11 requirements. (IRC R609, R703.8, N1102.1.2)
Electrical Requirements
7 Rules
General Wiring
All electrical installations shall comply with the 2023 National Electrical Code (NEC). (NEC 90.2)
Branch Circuits (Kitchen)
A minimum of two 20-ampere dedicated small-appliance branch circuits shall be provided for receptacle outlets serving the kitchen countertop surfaces. (NEC 210.52(B)(1))
Countertop Receptacles
Receptacle outlets shall be installed so that no point along the wall line is more than 24 inches horizontally from a receptacle outlet on countertop spaces. (NEC 210.52(C)(1))
Lighting Outlets
At least one wall-switch controlled lighting outlet shall be installed in every habitable room and kitchen. (NEC 210.70(A)(1))
GFCI Protection
All 125-volt, single-phase, 15- and 20-ampere receptacles installed in kitchens to serve countertop surfaces shall have ground-fault circuit-interrupter protection. (NEC 210.8(A)(6))
AFCI Protection
All 120-volt, single-phase, 15- and 20-ampere branch circuits supplying outlets or devices installed in kitchens shall be protected by a listed arc-fault circuit interrupter. (NEC 210.12(A))
Dedicated Circuits
Dedicated circuits are required for appliances such as dishwashers, garbage disposals, microwaves, and ranges, as per manufacturers' instructions and NEC requirements. (NEC 210.23, 422.12)
Plumbing Requirements
6 Rules
General Plumbing
All plumbing installations shall comply with the Illinois Plumbing Code (latest adopted edition by the local municipality). (IL Plumbing Code Section 890.100)
Water Supply
Water distribution piping shall be sized to provide adequate pressure and flow to all fixtures. New connections must be properly supported and protected. (IL Plumbing Code Section 890.1310)
Drainage, Waste, and Vent (DWV)
Drainage, waste, and vent piping shall be correctly sloped, sized, and vented to prevent trap siphonage and backpressure. (IL Plumbing Code Sections 890.1330, 890.1410)
Fixture Installation
Kitchen sinks, dishwashers, and other fixtures shall be installed with proper traps and air gaps where required to prevent backflow. (IL Plumbing Code Section 890.1500)
Backflow Prevention
Backflow prevention devices shall be installed where required to protect the potable water supply, particularly at fixtures with potential cross-contamination. (IL Plumbing Code Section 890.1130)
Protection of Piping
Piping in exterior walls or unheated spaces (including crawl spaces) in DuPage County's climate shall be protected from freezing. Pipes passing through or under foundations must be sleeved. (IL Plumbing Code Section 890.410, 890.1230)
Energy Efficiency
6 Rules
Thermal Envelope
The new bump-out must comply with the prescriptive or performance requirements of IRC Chapter 11 (Energy Efficiency) for DuPage County climate zone 5A. (IRC N1101.1, N1101.2)
Wall Insulation
Exterior walls shall have a minimum insulation R-value of R-20, or R-13 cavity insulation plus R-5 continuous insulation. (IRC Table N1102.1.2)
Floor Insulation (over unconditioned space)
Floors over unconditioned spaces (e.g., crawl space, exterior cantilevers) shall have a minimum insulation R-value of R-30. (IRC Table N1102.1.2)
Ceiling/Roof Insulation
Ceiling insulation shall have a minimum R-value of R-49. (IRC Table N1102.1.2)
Fenestration U-factor
Windows shall have a maximum U-factor of 0.30 and a maximum Solar Heat Gain Coefficient (SHGC) of 0.40. (IRC Table N1102.1.2)
Air Sealing
The building thermal envelope shall be sealed to limit air leakage, with a maximum air leakage rate of 3 air changes per hour (ACH) at 50 Pascals, as verified by a blower door test. (IRC N1102.4.1.2, N1102.4.1.3)
Fire Safety & Egress
3 Rules
Smoke Alarms
Existing smoke alarms must be interconnected throughout the dwelling unit. If the bump-out creates or expands a sleeping area, additional alarms may be required. (IRC R314.3)
Carbon Monoxide Alarms
Carbon monoxide alarms are required in all dwelling units with fuel-fired appliances or attached garages, located outside of each separate sleeping area. (IRC R315.3)
Egress
If the bump-out significantly alters the path of egress or creates a new habitable room, it must meet emergency escape and rescue opening requirements. (IRC R310)
