For the purpose of establishing rules and regulations for the fabrication, erection, construction, enlargement, alteration, repair, location and use of detached one- and two-family dwellings, their appurtenances and accessory structures, there is hereby adopted the 2021 edition of the International Residential Code for one- and two-family dwellings, promulgated by the International Code Council, together with all appendices thereof, except such portions thereof as are hereinafter expressly deleted, modified or amended.
A. While the 2021 edition of the International Residential Code for One- and Two-Family Dwellings and all appendices have hereinabove been adopted, the following exceptions thereto (consisting of certain deletions and changes) shall control wherever such exceptions are applicable or are in conflict with certain other provisions of that code:
1. Section 105, Permits, shall be deleted in its entirety and the following inserted in its place:
Section 105, Permits, Refer to Article II General Provisions, Section 21.203 of the Village Code for building permit requirements.
2. Section R108, Fees, shall be deleted in its entirety and the following inserted in its place:
R108. Appropriate Schedules. Article III - Fees, Bonds And Deposits of chapter 21, Building Code, of the Mount Prospect village code shall apply.
3. Section R110, Certificate Of Occupancy, shall be deleted in its entirety.
4. Section R112, Board Of Appeals, shall be deleted in its entirety and the following inserted in its place:
R112. Appeals. Any person shall have the right to appeal to the village manager a decision of the code official concerning the interpretation of this code or to request a modification of this code. Any application for appeal to the village manager shall be based on a claim that the true intent of this code or the rules legally adopted thereunder have been incorrectly interpreted or the provisions of this code do not fully apply.
5. Section R113.4, Violation Penalties, shall be deleted in its entirety and the following inserted in its place:
R113.4. Penalty: Section 21.403 of chapter 21, Building Code, of the Mount Prospect village code shall apply.
6. Section R113.4, Violation Penalties, shall be deleted in its entirety and the following inserted in its place:
R113.4. Penalty: Section 21.403 of chapter 21, Building Code, of the Mount Prospect village code shall apply
7. Table R301.2 shall be modified to include the following values in the table:
Weathering Probability = Severe
Ultimate Design Wind Speed = 107
Ground Snow Load = 30 psf
Frost Line Depth = 42 inches
Seismic Design Category A
Termite Infestation Probability = Slight to Moderate
Ice Barrier Underlayment Required = Yes
Air Freezing Index = 2,000
Mean Annual Temp = 47.3 degrees Fahrenheit
Special Wind Region = No
Windborne Debris Zone = No
8. Section 304, Minimum Floor Area Requirements, shall be amended by deleting the text and replacing it with the following:
304. Minimum Floor Area Requirements.
a. Minimum Floor Area Requirements, Houses: Except as otherwise provided by ordinance, minimum floor areas of houses and rooms therein shall meet the following standards:
(1) Minimum Floor Areas - Total Structures: The minimum floor area for the total structure of building shall be:
Type of Structure | Minimum area sq. ft. |
One story ranch house | 1,000 |
Split level or raised ranch house | 1,000 |
One and one-half story house | 950 |
Two story house | 800 |
The foregoing minimum floor area shall be measured at the first floor on the main floor level from the outside of exterior walls.
(2) Minimum Floor Areas – Non Sleeping Rooms: The minimum floor area requirements for non-sleeping rooms shall be:
Type of room | Minimum area sq. ft. |
Type of room | Minimum area sq. ft. |
Living and dining when in one room | 310 |
Living only in one room when dining room space is provided in kitchen or separate room | 220 |
Kitchen cooking only (including area occupied by equipment) | 100 |
Kitchen and dining when dining space is not provided elsewhere | 200 |
Kitchen and laundry (including area occupied by equipment) | 140 |
Kitchen, dining and laundry | 200 |
Utility room (including area occupied by equipment) | 100 |
Kitchen, laundry and utility | 200 |
(3) Minimum Floor Areas - Sleeping Rooms: The minimum floor area requirements for sleeping rooms shall be:
Type of room | Minimum area sq. ft. |
Major bedroom | 140 |
Second bedroom | 120 |
Additional bedroom | 100 |
(4) Minimum Floor Areas – All other rooms: the minimum floor requirements for other rooms shall be:
Type of room | Minimum area sq. ft. |
Major bathroom | 40 |
Master bedroom closet | 14 |
Other bedroom closets (at least one each) | 10 |
All other habitable rooms not herein-above set forth | 100 |
Minimum floor area for the foregoing shall be measured from the inside of all finished walls. | |
9. Section R309, Garages And Carports, is amended by inserting new subsections R309.6 and R309.7, to be and read as follows:
R309.6. Minimum Construction Requirements: Garages attached or built into residential buildings.
a. The construction of garages attached or built into and made a part of residential construction shall be of the same quality as required for the dwelling to which the garage is attached.
b. All floors of attached or built-in garages shall be five inches (5") below the grade of the floor of which it is attached or a part thereof and shall be pitched a minimum of one and one-half inch (11/2") from the rear of the garage towards the vehicle door. Floor drains shall not be allowed in the garage unless equipped with a triple-basin oil intercept.
c. There shall be no interconnection between a dwelling's forced air heating system and a garage. Supply or return air registers in the garages, which are connected to the dwelling's heating system, are prohibited.
R309.7. Minimum Construction Requirements: Detached garages.
a. Location of detached garages on lots shall conform to requirements of the Mount Prospect zoning ordinance.
b. Floors shall be not less than five inches (5") thick reinforced with #10 wire screen over a base of crushed stone or sand at least four inches (4") in depth. The base shall be placed on undisturbed soil. The floor shall be pitched a minimum of one and one-half inches (11/2") from the rear of the garage towards the vehicle door. Floor drains shall not be allowed in the garage.
c. Footings for frame garages shall be of not less than twelve inches (12") wide and not less than twelve inches (12") in depth around entire perimeter of slab. Footings for brick garages shall be concrete, not less than three and one-half feet (31/2') below grade and not less than twelve inches (12") wide and eight inches (8") thick. Foundation walls shall be a minimum of eight inches (8") thick. Footings shall be placed on firm soil free of organic matter.
d. Wall studs shall be spaced at not more than sixteen inches (16") on center and securely fastened to the bottom plate which shall be bolted to the floor. A double top plate shall be required and all wall studs and plates shall be a minimum of two inches by four inches (2" x 4"). Doubling of studs shall be required at all corners and jambs of openings more than three feet (3') in width.
e. Each corner is to be wind-braced outward from the top in two (2) directions to a minimum of four feet (4') from each corner at the bottom plate. Wind bracing shall be a minimum of one inch by four inches (1" x 4") and notched into the studding or an approved sheathing complying with R602.10.
f. All roof rafters must be at least two inches by six inches (2" x 6") and spaced not more than sixteen inches (16") o.c. Ridge board shall be required and of a size not less than two inches by six inches (2" x 6"). Ceiling ties of at least two inches by six inches (2" x 6") spaced evenly at maximum six (6) foot centers and a minimum
of three (3) collar ties not less than one inch by six inches (1" x 6") at not more than four foot (4') centers are required on all common rafter spans more than twelve feet (12') in width.
g. A minimum of one service door not less than two feet six inches by six feet eight inches (2'6" x 6'8") shall be required on all garages. At least one operable window with an area of at least five (5) square feet shall be installed.
h. The maximum garage door height shall be eight ft. (8').
i. Roof sheathing of not less than one-half inch (1/2") thick exterior grade plywood or one inch (1") thick nominal size rough sawn sheathing.
j. All detached garages are to be covered in a code approved air barrier.
10. A new section R331, Construction Site Requirements, shall be added as follows:
R331. Construction Site Requirements. The following regulations apply to residential room additions 500 square feet and over, demolitions of any type, new construction within or adjacent to residentially zoned properties, and any other type of construction work that presents a life-safety hazard to the property occupants, adjacent properties, and/or public-way.
a. Construction Site Fencing: A minimum perimeter chain-link lockable fencing of five (5) feet in height shall be required for all single-family development projects, including, but not limited to, new construction, teardowns, and major additions. The required fencing shall remain erect and be maintained until the structure is properly secured. Fence screening may be required, at the village's discretion, to prevent dust and debris from blowing onto adjacent properties or public way. Snow-type fencing is not allowed to serve as a construction fence.
b. Portable Washroom Facilities: Portable washroom facilities shall be placed on the construction site prior to work commencing and shall be placed within the confines of the fence and not be located within any required side yard or within any right-of-way.
c. Site Cleanliness: The property shall be cleaned at the end of each workday, including the removal of mud and debris from the street and sidewalks, and snow and ice from the sidewalks. Construction debris and litter shall be kept in a refuse container.
d. Silt Fence: A silt fence may be required in accordance with the detailed grading plan. The fence must be placed prior to any work commencing and must be maintained in good condition.
e. Dust Control: Any dust created due to job site construction must be contained on the property. Tenting of the area and use of wet saws and/or a hose is recommended.
f. Construction Mailbox: A construction mailbox shall be placed onsite and marked for construction document use only and not to be used as the property mailbox.
g. Construction Documents: All approved construction documents, including tree protection plans, shall be maintained onsite and placed in a weather-protected 6" minimum diameter drawing tube or construction mailbox. The tube or construction mailbox shall be mounted on the sign post and fully accessible.
11. Subsection R402.1, Wood Foundations, of section R402, Materials, is deleted in its entirety and replaced with the following:
R402.1. Wood Foundations: Wood foundations are hereby prohibited.
12. Subsection R404.2, Wood foundation walls, of section R404, Foundation and Retaining Walls, is deleted in its entirety and replaced with the following:
R404.2. Wood foundations walls: Wood foundation walls are hereby prohibited.
13. Section R408, Under-floor Space, is amended of by adding a new subsection R408.9, to be and read as follows:
R408.9. Minimum Depth And Sump Pump:
a. Minimum Depth: The minimum depth for crawl spaces shall be thirty six inches (36") from the bottom of the floor joists to the top of the finished slush coat.
b. Slush Coat: All crawl spaces shall have a minimum two inch (2") slush coat covering a minimum four inch (4") #6 stone with a vapor retarder per R506.2.3.
c. Sump Pump: All crawl spaces shall have a sump pump and drain tile system installed per the plumbing code unless otherwise approved by the code official due to site conditions and surrounding drainage property conditions.
d. Plenum: Crawl spaces shall not be used as an open plenum for HVAC.
P2904.1 General. The design and installation of residential fire sprinkler systems shall be in accordance with NFPA 13D or Section P2904, which shall be considered equivalent to NFPA 13D. Partial residential sprinkler systems shall be permitted to be installed only in buildings not required to be equipped with a residential sprinkler system in single family detached residences that meet all the requirements set forth in the definition of a Limited Residential Fire Suppression System (LRFSS) as provided for in Village Code Section 21.501. Section P2904 shall apply to LRFSS, stand- alone and multipurpose wet-pipe sprinkler
systems that do not include the use of antifreeze. A multipurpose fire sprinkler system shall provide domestic water to both fire sprinklers and plumbing fixtures. A stand-alone sprinkler system shall be separate and independent from the water distribution system. A backflow preventer shall not be required to separate a stand-alone sprinkler system from the water distribution system.
(Ord. 6303, 2-21-2017; amd. Ord. 6370, 2-20-2018; Ord. 6607, 2-15-2022)