The aim of this article is to provide you with a general overview of building code and to leave you with an understanding of their importance in building construction today worldwide as well as in the US and links to key information sources concerning them.
 
What is Building Code?
By definition building codes prescribe minimum standards for building construction.
In the US the main codes related to building elements, including wall and roof assemblies, are the International Building Code (IBC) and International Residential Code (IRC) by the International Code Council (ICC) which depend upon referenced standards such as those by ASTM international (formerly the American Society for Testing and Materials) to validate their criteria.  The US American National Standards Institute (ANSI) standards also cover building and the Occupational Health and Safety Administration (OSHA) 1926 standards relate to the construction industry.
Other codes include fire protection, electrical, plumbing and mechanical codes and sections of other ICC codes that apply to dwellings, business premises or construction objects, such as canopies and radio or television antennae.
Building codes maybe prescriptive or performance based although in recent years there has been a move towards those with more performance based requirements and fewer prescriptive requirements.
The practice of developing, approving and enforcing codes varies worldwide and may change in time. There are four key building code types in the world today: national, model, local building codes and the EN Eurocodes.

National Building Code

In some countries national building codes and variants of them are developed by government agencies or similar organizations and enforced nationally through central government.

EN Eurocode
EN Eurocodes are European building codes that have superseded older European Union (EU) members’ national building codes.

Model Building Codes
In some countries, such as the US, where construction regulation and fire safety is predominantly controlled by state authorities, model building code systems are used. These have legal status if they are adopted by a judicial state authority. Their developers ask that these authorities reference the codes in their regulations and order documents in order for them to become law.
In the past all major cities in the US had their own building codes. Now, due to the increasing complexity and cost of developing building regulations, nearly all US state authorities adopt model codes.

Local Building Code
There are still instances when some local or city jurisdictions choose to develop their own building codes.

Why are building codes important?
The building industry is driven by codes and standards to protect us from possible manufacturing errors.
The core objectives of building code are to protect public health and safety and general welfare as related to building construction and structural and mechanical integrity. They can become law in a particular area of jurisdiction when they are enacted by a relevant governmental or private authority, such as a county court.

Who are building codes used by?
It is intended that building codes are applied by building design teams (including architects,  engineers, contractors, subcontractors, developers, landlords and leaseholders, facility managers), building department regulators and inspectors as well as insurers, scientists and building product and material manufacturers and suppliers.

Where are building codes applied?
Building codes can be applied nationally, locally or regionally according to areas of jurisdiction.
Fifty US states have adopted the International Building and Residential Codes at county jurisdictional level, including Florida.
As an example, the 2014 Florida Building Code, 5th Ed. contains substantial content from the 2012 International Building Code.

How are building codes used?
Building codes are primarily used during the design process, the building permit process and building compliance verification but also used at the research and development stage of building products.
Building designers refer to codes such as the IBC/IRC during the building design process. When applying for a building permit, they have to demonstrate how each code objective is met.
Building departments refer to them whilst reviewing plans submitted to them prior to construction during the permit decision process.
Building inspectors refer to them to verify compliance to standards on-site during construction.