HUD / Modular / CBC2016


Modular Buildings and Modular Homes are sectional prefabricated buildings, or houses, that consist of multiple sections called modules. “Modular” is a method of construction verses “stick-built” and other methods such as off-site construction. The modules are six sided boxes constructed in a remote facility, then delivered to their intended site of use. Using a crane, the modules are set onto the building’s foundation and joined together to make a single building. The modules can be placed side-by-side, end-to-end, or stacked, allowing a wide variety of configurations and styles in the building layout.

Modular Buildings, also called Prefabricated Buildings, differ from HUD Homes, which are also called Manufactured Homes, in two ways. First, Modular Homes do not have axles or a frame, meaning that they are typically transported to their site by means of flat-bed trucks. Secondly, Modular Buildings must conform to all local building codes for their proposed use, while Manufactured Homes, made in the United States, are required to conform to federal codes governed by HUD (U.S. Department of Housing and Urban Development). There are some Residential Modular Buildings that are built on a steel frame (referred to as on-frame modular) that do meet local building codes and are considered Modular Homes, rather than Manufactured Homes.

Modular Buildings may be used for long-term, temporary or permanent facilities, such as construction camps, schools and classrooms, civilian and military housing, and industrial facilities. Modular Buildings are used in remote and rural areas where conventional construction may not be reasonable or possible, for example, the Halley VI accommodation pods used for a BAS Antarctic expedition. Other uses have included churches, health care facilities, sales and retail offices, fast food restaurants and cruise ship construction.


Modular components are typically constructed indoors on assembly lines. Independent building inspectors are on site to supervise the construction and ensure that the company adheres to all building codes during assembly. Modules construction may take as little as ten days but more often one to three months. Completed modules are transported to the building site and assembled by a crane. Placement of the modules may take from several hours to several days. Once assembled, Modular Buildings are essentially indistinguishable from typical site-built structures.


Modular Buildings are often priced lower than their site-built counterparts, for a variety of reasons. Manufacturers cite the following reasons for the typically lower cost/price of these dwellings:

Speed of construction/faster return on investment. Modular construction allows for the building and the site work to be completed simultaneously, reducing the overall completion schedule by as much as 50%.

Indoor construction assembly is independent of weather, which increases work efficiency and avoids damaged building material. Favorable pricing from suppliers, Large-scale manufacturers can effectively bargain with suppliers for discounts on materials.

Ability to service remote locations particularly in locations far from industrial centers, there can be much higher costs to build a site-built house in a remote area or an area experiencing a construction boom such as mining towns. Modular Homes can be built in major towns and sold to regional areas.

Low waste with the same plans being constantly built the manufacturer has records of exactly what quantity of materials is needed for a given job. While waste from a site-built dwelling may typically fill several large dumpsters, construction of a modular dwelling generates much less waste.

Environmentally friendly construction process Modular construction reduces waste and site disturbance compared to site-built structures.

Flexibility conventional buildings can be difficult to extend, however with a modular building you can simply add sections, or even entire floors.

Healthier because Modular Homes are built in a factory, the materials are stored indoors in a controlled environment, eliminating the risk of mold, mildew, rust, and sun damage that can often lead to human respiratory problems. Traditional site-built homes are always at risk from these threats.


Volumetric: Transporting the completed Modular Building sections take up a lot of space. This is balanced with the speed of construction once arrived on site.

Flexibility: Due to transport and sometimes manufacturing restrictions, module size can be limited, affecting room sizes. Panelized forms and flat pack versions can provide easier shipment, and most manufacturers have flexibility in their processes to cope with the majority of size requirements.


As recently as just a few years ago some home buyers and some lending institutions resisted consideration of Modular Homes as equivalent in value to site-built homes. While the homes themselves may be of equivalent quality, entrenched zoning regulations and psychological marketplace factors did create hurdles for some buyers or builders of modular homes. Since that time Modular Homes are becoming readily accepted all over the world and today’s Modular Homes are becoming the preferred choice for Value Conscience Homeowners, Developers and City Planners. They all realize when Modular Construction Technologies are integrated with precisely coordinated shorter building cycles, these two facts alone represent such a tremendous savings to the project’s total budget, It’s easy to see why Modular Construction is becoming the new standard. When you consider the world-wide need for structural growth of every kind and the continued demands on the Planet’s limited resources, it’s very clear to see that Green Galaxy’s Vision for Advanced Building Materials and Technologies is the only logical choice.


Especially as many financially strapped cities must find ways to fund local Urban Redevelopment Projects so that local Affordable Housing Projects can be built. Every Builder and Developer has to struggle with the challenge of where to find affordable In-fill Lots and Raw Land to develop. Many building opportunities never get started due to the high cost of the land, it just doesn’t pencil out utilizing traditional construction methods. However; Smart Builders and Developers are now turning to Modular Construction Technologies so that projects will now pencil out. Recent innovations in Modular Construction allow Modular Buildings to be indistinguishable from site-built structures.


Differences include the building codes that govern the construction, types of material used and how they are appraised by banks for lending purposes. The codes that govern the construction of modular homes are exactly the same codes that govern the construction of site-constructed homes. In the United States, all modular homes are constructed according to the International Building Code (IBC), IRC, BOCA or the code that has been adopted by the local jurisdiction.


The materials used in modular homes are the same as site constructed homes. Wood-frame floors, walls and roof are the most typical. Some modular homes include brick or stone exteriors, granite counters and steeply pitched roofs. All modular are designed to sit on a perimeter foundation or basement. In contrast, HUD Homes are constructed with a steel chassis that is integral to the integrity of the floor system. HUD Homes often require special lenders. Most companies have standard plans. However, all modular buildings can be custom built to a client’s specifications. Today’s designs include multi-story units, multi-family units and entire apartment complexes. The negative stereotype commonly associated with HUD Homes has prompted some manufacturers to start using the term “off-site construction.”


Typically, modular dwellings are built to local, state or council code, resulting in dwellings from a given manufacturing facility having differing construction standards depending on the final destination of the modules. For example, homes built for final assembly in a hurricane-prone area may include additional bracing to meet local building codes. Steel and/or wood framing are common options for building a modular home. Some US courts have ruled that zoning restrictions applicable to mobile homes do not apply to modular homes since modular homes are designed to have a permanent foundation. Additionally, in the US, valuation differences between modular homes and site-built homes are often negligible in real estate appraisal practice; modular homes can, in some market areas, (depending on local appraisal practices per Uniform Standards of Professional Appraisal Practice) be evaluated the same way as site-built dwellings of similar quality. Manufactured home parks are governed by additional legislation that does not apply to permanent modular homes. Possible developments in equivalence between modular and site-built housing types for the purposes of real estate appraisals, financing and zoning may increase the sales of modular homes over time.


According to manufacturers, modular homes are designed to be stronger than traditional homes by, for example, replacing nails with screws, adding glue to joints, and using 10-20% more lumber than conventional housing. This is to help the modules maintain their structural integrity as they are transported on trucks to the construction site; however, it is difficult to predict the final building strength since the modules need to endure transportation stresses that traditional homes never experience. When FEMA studied the destruction wrought by Hurricane Andrew in Dade County Florida, they concluded that modular and masonry homes fared best compared to other construction.


Modular buildings can be assembled on top of multiple foundation surfaces, such as a crawl space, stilts (for areas that are prone to flooding), full basements or standard slab at grade. They can also be built to multi-story heights. Motels and other multi-family structures have been built using modular construction techniques. The height to which a modular structure can be built depends on jurisdiction.

Exterior wall surfaces can be finalized in the plant production process or in the case of brick/stone veneers, field applications may be the builders’ choice. Roof systems also can be applied in the field after the basic installation is completed. Weather, population density, geographical distances, and local housing architecture play a role in the use of modular construction for home building. Because modular construction is so adaptable, it has begun to permeate every region of the country.