Okay, let's break down this situation and the relevant code sections.

Understanding the Code Sections



Type III-B Construction

This is a type of construction where the exterior walls are of noncombustible materials and the interior structural elements (walls, floors, roof) are of any material permitted by the Building Code. The "-B" indicates that it's

unprotected noncombustible or combustible. This is the key distinction! Article 334 (NM Cable)

This article governs the use of Nonmetallic-Sheathed Cable (NM, NM-B, Romex). The general rule is that NM cable can be used in Type III construction. However, there are exceptions, and the specific wording is crucial: Art. 334.10(3) "(3) Type III, IV, and V construction except as prohibited in 334.12" Art 334.12(A)(2) "(2) In multifamily dwellings or other structures containing more than two dwelling units above grade. This shall not apply to Type III and V construction unless prohibited elsewhere in this Code" Art 334.12(B)(2) "(2) Embedded in poured concrete, concrete blocks, or brick or tile walls."

Article 518 (Places of Assembly)

This article addresses the electrical wiring and equipment in places of assembly. A "place of assembly" is defined broadly in Article 100 and generally includes spaces where groups of people gather for various purposes. Your restaurant's dining area clearly falls under this definition.

518.4(B) Wiring Methods

This is the crucial part. This section generally dictates the wiring methods permitted in places of assembly. It allows for NM cable in certain circumstances, specifically in

buildings of Type III, IV, or V construction where the building or parts thereof are not required to be fire-rated.Applying the Code to Your Situation


Dining Area

The dining area is a "place of assembly" according to Article 518. The dining area is

non-fire-rated. Therefore, according to 518.4(B), NM cable IS permitted in the dining area unless there are other overriding local amendments or specific requirements in the Building Code.2. Kitchen Area

The kitchen, while part of the restaurant establishment, is NOT a "place of assembly" under Article 518's definition. It's a work area, not a space where a large group of people regularly gathers for entertainment, worship, or similar purposes. However,

the kitchen is fire-rated construction. This is the critical point. Article 334 generally prohibits NM cable in fire-rated construction.

Conclusion and Recommendation



Dining Area

NM cable is generally permitted in the dining area based on 518.4(B), assuming the dining area is indeed not fire-rated.*

Kitchen Area

NM cable

IS NOT permitted in the fire-rated kitchen area. You will need to use a wiring method suitable for fire-rated construction, typically requiring metal raceways (EMT, IMC, Rigid) and wiring types appropriate for those raceways (THHN/THWN).

Important Considerations and Next Steps


Local Amendments

Always check for any local amendments to the NEC. Some jurisdictions might have stricter rules regarding NM cable.2.

Building Code

The Building Code is paramount. The electrical inspector will be guided by the Building Code's requirements for fire-rated construction. If the Building Code requires fire-rated assemblies, you must adhere to it.3.

Specific Fire-Rating Requirements

Determine the exact fire-rating requirements for the kitchen walls (e.g., 1-hour, 2-hour). This will influence the type of wiring method you choose.4.

Consult with the Electrical Inspector

The best course of action is to have a direct conversation with the electrical inspector. Present your understanding of the code and clarify any ambiguities. This will ensure that your installation meets their requirements and avoids costly rework.5.

Consider Cost and Labor

While metal raceways and appropriate wiring are more expensive than NM cable, the cost of non-compliance and rework is far greater. Factor in labor costs as well.

In summary, while you can likely use NM cable in the non-fire-rated dining area, you will need to use a metallic raceway system (EMT, IMC, Rigid) and appropriate wiring (THHN/THWN) in the fire-rated kitchen area. Always confirm these interpretations with the local electrical inspector and the Building Code official. Flag for review