Modular Buildings

Used as long-term temporary or permanent facilities, modular or prefabricated buildings are used for a number of applications such as churches, schools and universities, offices, gyms and hospitals. They are also used for temporary offices at construction sites, for disaster relief housing and for military barracks. Modular building systems are far less costly than conventional building methods, and complete fabrications are able to be finished from design to assembly in a matter of weeks. Storage buildings, prefab shelters, security guard houses and modular offices are common uses for modular or prefabricated building. Far less costly in terms of materials, labor and time than conventional construction methods, modular buildings are available in stock sizes and layouts, or with custom design and specifications. Relocatable buildings and portable buildings are extremely versatile and are useful for installation in many different fields, even in remote and rural locations. Larger buildings such as prefabricated garages might be constructed from a durable metal such as steel or aluminum. Pre engineered buildings are able to be used in a number of different applications because of the versatility of their shape, size and capabilities.

The term prefabricated may refer to the components, modules or transportable sections of the structure or building. Typically, the elements of the building are constructed in a factory and then transported either partially or completely assembled to the intended site of installation. A prefabricated or modular building is able to include all the necessary components such as walls, floor trusses, a variety of windows, complete HVAC systems, plumbing, electrical wiring and lighting and interior finishes. Using the method of modular building offers many benefits when compared to traditional site-constructed facilities. In situations where fast construction and low cost are important, modular structures offer a long-lasting solution. Structures are able to be designed to make existing buildings, or painted to stand out through the use of colors and trims. For classrooms, clean rooms, large gyms, churches and commercial facilities, modular building offers an ideal solution to many factors that normally slow the process of building.

Modular building manufacturers provide flexibility and other advantages over site-construction, such as cost savings, speed of occupancy, factory-controlled quality and ease of expansion and relocation. The most significant advantage of modular buildings is the time saved although actual production times will vary according to the complexity of the design, the skill of the engineers and delivery times. However, many modular buildings are fabricated from stock designs and therefore do not need to go through the process of design. Then during the construction process, the buildings only need to be assembled together instead of actually being constructed onsite. Therefore, modular buildings are less susceptible to delays due to lack of building materials and labor or due to effects of weather which can stall traditional building schedules. Prefab buildings are typically built according to a carefully monitored timetable within the factory plant, and some manufacturers even guarantee a certain number of weeks until a building is available for installation. Modular building fabrication uses factory methods to greatly enhance quality and reduce manufacturing time and cost.

There are a number of important factors to consider before undertaking a building job of any sort, and especially before undertaking a modular building job. National and local electrical and construction standards must be explored before a prefabricated structure can be installed. It may not be necessary for a landowner to obtain a building permit to erect a modular structure, but it is important to check with the local standards. The structure of the foundation needs to be considered, whether one will be built or if it is not needed, and what material it should be constructed from if it is required. It will need to support not only the weight of the structure, but also to sustain the force it could experience in rough weather such as hurricanes or heavy winds and to prevent the collapse of the prefab shelter. Modular buildings can be constructed from lumber, polyvinyl or a durable metal such as steel. Depending on size, location and intended use, one of these materials might be more suitable than another. Steel is a common modular building material as it is strong and resistant to corrosion. It is able to survive extreme temperatures and weather without deteriorating and therefore saves money in terms of maintenance over time. The popularity of using modular and prefabricated buildings will continue to increase due to the benefits in cost reduction, construction speed, portability and range of location possibilities. Modular buildings can be used permanently, as temporary spaces, outdoors or built in an existing structure. Especially in areas with limited transportation and where conventional building supplies may be hard to come by, modular building offers a logical and effective solution.

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Modular Building Types

• Aluminum buildings are fabricated from low maintenance, lightweight corrosive resistant aluminum. Their convenience is their durability and flexibility in size and use.
  
• Booth manufacturers construct portable enclosed steel structures for applications such as security, revenue and/or access control booths or gate houses.
• Building systems assemble prefabricated parts to construct permanent buildings.
• Bullet-proof structures meet standards for resisting impact from bullets and other fast moving/high powered objects.
  
• Guard Houses are often placed at entrances to secure areas and serve as stations of clearance and general work activity for security or admissions personnel. Sizes will vary by need.
  
• Metal buildings are comprised mainly of select metal material and can be used for anything from storage to protection in various sizes.
  
• Portable buildings are buildings that can be easily moved or relocated. They are designed to be moved without significant structural modification; examples include portable hospital facilities, classrooms, offices, etc.
  
• Pre Engineered Buildings are built of or with prefabricated sections or parts and are similar to prefabricated structures in use and variety.
  
• Prefab buildings are a type of modular building built with prefabricated parts.
• Prefabricated buildings are different from modular buildings in that they are delivered fully assembled to site. Sizes and uses are varying.
  
• Prefabricated garages are modular structures often used to add on to a previously existing garage.
• Steel buildings are fabricated primarily of steel and are often found in industrial settings as well as for outdoor use. Size possibilities are unlimited.
  
• Storage buildings can be made from prefabricated parts, usually those composed of steel materials.
• Walk-in enclosures are enclosed areas, which can be entered and worked in. Guard houses, x-ray rooms and communications rooms are examples of these.

Modular Building Terms

Accessory - Products for modular buildings that add to a fundamental solid panel building like a window, door, roof vent, etc.
 
All-bolted Steel Floor - Floor joists of galvanized steel that reach across each module from both sides as well as being bolted to both floor side beams
 
Aluminum - A light, corrosion and oxidization resistant, metallic material with high electrical and temperature conductivity. This metal is commonly used in construction of modular buildings.

Anchor - Construction for assisting the stabilizing of modular buildings or portable buildings to the ground, combined with straps or cables and turnbuckles or split bolts.

Anodized - Material that has a metal oxide finish formed by a process that produces a durable semi-translucent finish in varying colors.

Architect of Record/Engineer - Architect or engineer who oversees the entire modular buildings projects. This is not the same as the manufacturer's engineer.
 
Beam - A modular buildings component that has bending loads subject to it. The three types are continuous, simple and cantilever.
 
Bottom Board - Material placed beneath the floor joists of a modular building or portable building for the protection and keeping in of insulation as well as keeping the building weathertight. Bottom board is typically composed of paper that is fiberglass reinforced, asphalt impregnated or asphalt board.
 
Bracing - The use of angles, cables or rods in the roof's plane and walls to convey loads to the foundation like seismic, crane thrusts and wind.  
 
Building - A structure that forms an enclosed, partially enclosed or open area made through a process of planning using components, materials and subsystems to achieve particular usage conditions.  
 
Building Code - Industry recognized agencies establish specific regulations pertaining to building designs such as design loads, procedures and construction details for structures, typically as applied to certain political jurisdictions like city, county, state, etc.  
 
Cantilever Beam - A type of beam that provides support at only one end allowing the other end to move freely.  
 
Cladding - Outer wall paneling and exterior metal roof of the metal building system found in prefabricated steel buildings.

Clear-span - Interior free of columns.
 
Collateral Loads - Weight caused by further permanent material necessitated by the building contract beyond the building system, like mechanical and electrical systems, sprinklers, ceilings and partitions.  
 
Column - A primary building component designed to convey the load from the main roof trusses, beams or rafters to the foundation.

Composite - Substance consisting of more than one material with each retaining their distinct beneficial characteristics.

Cool Roof - A metal roof meeting standards for Solar Reflectance and Infrared Emittance as determined by the CRRC. Cool roofs are sometimes painted white or made from specific reflective materials.
 
Elastic Design - Conception of design using the property of the materials permitting for temporary shape deformation in a predetermined load range.  

Fabrication - Process of manufacturing done in the plant to transform raw material into completed components for prefabricated steel buildings. The fundamental processes are welding, cold forming, punching, painting and cleaning.

Fiberglass - Filaments of glass used in a process with polyester resins, catalysts and hardeners to be molded into shapes.

Gable - Building style, which usually includes one peak with the roof sloping at each side of modular buildings.

Galvanized Steel - Steel covered with zinc metal.

Girt - A horizontal structural component mounted to endwalls or sidewall columns of modular buildings, which serves to support paneling.

Hardwall - Walls of modular buildings that are constructed of masonry, block, tilt-up or pre-cast.

Installation - The construction of prefabricated buildings components of a metal building to produce a finalized portable building - done on location.
 
Joist - A light weight beam that serves to support a roof or floor.  

Magnetic Shielding - When magnetic fields, electromagnetic or radio frequency interference are deterred and safeguarded from structure.
 
Manufacturer's Engineer - The engineer under the employ of the manufacturer, who is responsible for the structural design of a prefabricated steel buildings systems formed by the manufacturer.

Multi-span - The interior of building includes columns.

Purlin - The horizontal structure that serves to support the roof covering transferring loads to the main framing members of modular buildings.  
 
R-Value - R-value measures insulation's resistance to heat flow; it is important for temperature control issues.
 
Rigid Frame - Structural frame composed of components attached with moment connections causing stability in the frame relative to the design loads, removing the need for bracing in its plane.
 
Roofing - Modular buildings component that is attached to the frame of the roof covering the building, protecting against weather and fire.

Single Slope - A peak with one slope.

Sound Attenuation - Designed specifically to reduce noise from inside modular buildings to the outside.

Stainless Steel - Resistant to chemicals and corrosion.

Steel - Iron that contains carbon as an essential alloying component up to 1.8% and is workable in certain circumstances.

Structural Insulated Panels (SIPs) - Also known as foam core panels. SIPs are prefabricated insulated structural elements consisting of an engineered sand laminate with a solid foam core four to eight inches thick.

Truss - Designed to perform as a beam since it consists of three or more members that each carry a compression or tension force.  

Turnkey - A product which has been completely outsourced for fabrication, leaving all aspects of manufacturing, material acquirement, assembly, installation and testing to the subcontractor. Turnkey systems are delivered and installed to the purchaser ready to use.