The Comprehensive Guide To Home Renovations Large and Small
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Building Codes and Permits

Note: definitions for the underlined words in this chapter are found in the Glossary of Terms.

Every new construction project and any remodeling project involving structural or mechanical changes must comply with building code and permit requirements. Most local governments require a building permit and inspection process to insure that local building codes are met. Local building codes insure that material standards, installation guidelines, and structural requirements are met.

For over 190 years, there have been national building code requirements for structural and mechanical safety purposes; and to help insure that work has been completed correctly. Most local building codes reflect national building code standards.

In an effort to create an international standard, the International Code Council (ICC) was instituted in 2003; providing uniform building code guidelines on a world-wide basis. Of course, local codes supersede all other building codes. And local authorities have the final say on any given project.

Before You Begin a Project

One of the first steps any homeowner should take before starting a renovation project is to contact the local building authority to inquire as to what codes exist. And also what permits, if any, will be required. You may be required to fill out a form that includes a detailed description of the project, the address and legal description of the property, as well as estimated project costs.

The local building authority may require 2 to 4 sets of plans or drawings – complete with floor and elevation plans, to be evaluated and approved. Once the plans have been thoroughly checked over and approved, they will be stamped. Or, a written approval notice will be mailed to the project owner.

Normally, one set of approved plans will be kept by the local building authority, and one set mailed back to the applicant for their own records. Another set will be provided; to be displayed at the project site until the project has been completed.

Once renovation plans are approved, permit fees are assessed. Information regarding required inspections as work progresses is also provided. Amount of fees will be based on the overall cost of the project. Some permits are issued in stages, with the permit for the next aspect of work being issued after the previous phase has been completed, inspected, and approved.

Local building inspectors check all work as it progresses; the project is considered complete only after the final inspection and approval has been made.

General Building Permit Code Requirements

Some of the more general building permit code requirements are:

  • Light and ventilation – Including doors, windows, louvers, mechanical systems (HVAC), and other approved openings. In habitable rooms, window area must equal at least 8-percent of the floor space; at least half of the window area must be open able. Mechanical ventilation can replace operable windows. Bathrooms must ventilate to the outside with an intermittent rate of 5 cfm, and a continuous rate of 20 cfm. Bedrooms must supply outside air at a rate of 15 cfm for each occupant, primary bedrooms based on 2 occupants, additional bedrooms based on 1 occupant.
  • Exits and openings – Habitable basements and bedrooms must have a minimum of 2 exits. One can be the entrance; the other must be an emergency door or egress window not requiring a tool or key to operate. Window openings must have a minimum height of 34-inches with a minimum width of 20-inches. Basement windows must have window wells; those deeper than 44-inches must also have steps, with additional requirements. All exits must operate from the inside with no special tools or knowledge.
  • Room ProportionsHabitable rooms must have dimensions of at least 7X7 feet, with 7½-foot headroom; measurement is from the finished floor to lowest part of ceiling. Obstructions must be spaced at least 4-feet apart; no less than 7-foot headspace from the obstruction to the finished floor. For sloped ceilings, at least 50-percent of the total floor area must have 7 ½-foot ceilings; no part of the floor can have ceilings less than 5-feet from the finished floor. Kitchens should have at least 50 sq. ft. gross floor area; hallways must be at least 3-feet wide. At least one habitable room in the house requires a minimum of 120 sq. ft. floor space; other habitable rooms require a minimum of 70 sq. ft. floor space.
  • Fire safety – Interconnected and concealed spaces such as soffits, stair stringers, ducts, drop and cove ceilings, fireplaces, chimneys, and areas around vents must be fire blocked to prevent fire spread. Perimeter (or exterior) walls are to be constructed on both sides to resist fire exposure for at least one hour. Note: a commonly used material for the interior side of these walls is 5/8-inch sheetrock. Approved batt or blanket insulation must be secured between studs and partitions. From ceiling to floor at a minimum of 10-inch intervals; vertically and horizontally. Other approved spray-on or loose insulation materials and wall coverings must meet flame and smoke spread ratings. Smoke alarms must be installed at least one per floor, including one in each bedroom and bedroom hallway. Multiple alarms must be wired together to activate all alarms if one triggers.

While general building code requirements must be met for any project, there are stringent additional code requirements for specialized aspects of the project, such as electrical and plumbing.


While some local, state, or provincial governments may not require licensing or certification of general building contractors, electrical contractors are much more closely regulated.

It is a universal requirement that electrical systems and wiring be either installed by a licensed electrician, or inspected and approved by a certified electrical inspector. While the National electrical code (NEC) is the authority for evaluating wiring, electrical inspectors also adhere to local building and electrical codes.

An important aspect of any electrical wiring project is careful planning. This not only insures adequate service for immediate needs, but projects ahead for possible future needs, as well. When planning your project, you may want to visit with your local inspector. He or she can tell you which code requirements are necessary for your project, and can give you an information packet that outlines code requirements.

Electrical Requirement Considerations

A 15 amp receptacle might be adequate for a bedroom. But a family recreation room might require at least two 20 amp circuits. Building a large addition can add a considerable load to the main electrical service; in about 25% of existing homes, upgrades are required.

Many structures have 60 amp service boxes. One common solution to meet the requirements of additional circuits is to upgrade to a 150 amp box. In some cases, the electrical service box may be adequate, but there is no space left to add new circuits. In that type situation a sub-panel can be added to provide additional space.

Residential electrical work can be done by the homeowner, as long as the work is inspected and certified by an electrical inspector. However, there are technical aspects such as figuring circuit loads and wiring the service boxes that make the project difficult. And, of course, working with electricity is a serious matter and can be dangerous. Therefore, hiring a licensed electrician may be well worth the investment.

The following are some of the more common electrical code requirements:

  • The rating of an outlet box must match the rating of the circuit. There is a difference between an outlet box for a 20 amp circuit, and one for a 15 amp circuit. Using a 20 amp outlet on a 15 amp circuit could overload the circuit and create a hazard.
  • Due to the close proximity of water and potential shock hazard, kitchen and bathroom areas, as well as all exterior outlets, must be protected by GFCI (Ground-fault circuit interrupter) outlets. Devices that automatically shut off in the presence of a ground fault. In most localities, all outlets must be properly grounded.
  • Electrical service cables installed in the framing must have at least 1¼-inch of wood protecting the wire from nails or screws driven into the framing studs. In areas where 2X2-inch framing is used, metal protector plates must be properly placed to protect the wiring from screws or nails.


Plumbing systems are another aspect of new construction and renovation projects that have stringent and complex code guidelines. Again, while local codes and requirements may vary, most building officials and inspectors make evaluations based on the National uniform plumbing code; a highly technical, hard-to-read manual. Many bookstores carry handbooks based on the National uniform plumbing code, presenting material in layman’s terms; in an easier to comprehend format.

To accommodate code variations from one local to the next, some handbooks include three separate plumbing zones. Again, local codes and requirements always supersede national code guidelines. Many local building inspectors provide convenient summary sheets of applicable code requirements for each individual project.

Most local authorities require a permit for plumbing projects; or at least the plumbing phase of a larger project, requiring detailed plans or drawings. At least three copies are usually required for review; each must include a diagram of the water supply system, and the drain-waste-vent system.

If code requirements are met, a permit is issued, granting legal permission to begin work. An inspector will visit the work site at or near completion of the project for final approval if all code requirements have been met.

Meeting Guidelines

Calculating water distribution pipe diameter and length is complicated. Each fixture comes with a “unit rating.” This helps in calculating diameter and length needs. Some examples are toilet – 3 units, vanity sink – 1 unit, dishwasher – 2 units, bathtub –2 units, and shower – 2 units.

The sum of unit ratings for all fixtures to be connected is the “total demand.” In conjunction with the total length of pipe from the street to the farthest fixture in the project, this determines pipe diameter requirements. The size of pipe from the street to the meter will also determine required diameters to meet the demand.

Full-bore gate valves are required on the street side and house side of the water meter, as well as on the inlet side of heating system boilers and water heaters. All fixtures should have accessible shutoff valves; this can include the ball valve type. All sill-cocks should have individual control valves inside the house.

In many localities, water hammer arresters are required to prevent pipes from rattling or vibrating when a fast acting valve is opened on a fixture. Vacuum breakers are required in a system to prevent any contaminated water from being drawn back into the system from outdoor sill-cocks or branch pipes that run underground.

Because plumbing pipe is frequently routed through framing members, there are restrictions as to what size holes or notches can be cut in the various lumber sizes. For example, in a load-bearing 2X6-inch stud, the maximum hole size is 2 ¼-inches, maximum notch size is 1 3/8-inches deep. For a non-load-bearing 2X6-inch stud the maximum size hole is 3 5/16-inches in diameter; maximum notch size is 2 3/16-inches deep.

Drainage Pipes

In most areas, drain cleanouts are required at the end of each horizontal pipe run. Individual fixtures require a minimum drain trap size determined by the numerical fixture unit rating discussed earlier.

There are also minimum horizontal and vertical drain pipe size requirements. Again, these are determined by the sum of fixture units that will feed into them. There are pipe support interval requirements for both horizontal and vertical runs of pipe, determined by length and pipe type; such as copper, ABS, PVC, CPVC, galvanized iron, and cast iron.

Additionally, there are venting requirements; including pipe sizes, critical distances, vent pipe orientation to drain pipe (upward at no less than a 45-degree angle), as well as wet venting and auxiliary venting size and distance requirements.

Finally, most localities have restrictions on which type of pipe can be used for certain applications, such as type underground sewer pipe running to a main sewer line or septic system.

Remember, for any project code requirement information, the local building inspector is your best source, and the final authority on meeting local requirements and final project approval.

< Chapter 1 (House Structure Basics)  |  Chapter 3 (Universal Design) >


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