Skip to content

Relocatable Buildings vs. Permanent Modular Construction: What's the Difference?

Modular construction is revolutionizing the construction industry as a super-efficient and sustainable solution for building faster, stronger, and more predictably.

There are two types of modular structures- Relocatable Buildings and Permanent Modular Construction. While both construction types offer a plethora of benefits, there are distinct differences.

In this article, we'll help you understand the differences between permanent modular construction and relocatable buildings.

gotham1

This hospital in New York is an  MBI Awards of Distinction-winning example of permanent modular construction.

tinycabins

These luxury cabins are an MBI Awards of Distinction-winning example of relocatable buildings.

What is Modular Construction?

Also known as volumetric construction, modular construction uses individual sections or modules, which are assembled off-site in factories under controlled conditions, to create complete structures of all shapes and sizes.

The modules themselves use the same designs and materials as traditional construction and meet all the same building standards and codes. The modules are then transported and put together at the final construction site.

There are two main methods of modular construction:

Permanent Modular Construction (PMC)

PMC is a sustainable and innovative building technique that utilizes offsite and lean manufacturing methods to prefabricate either single or multi-story structures in modular sections. PMC can be integrated into an existing structure or can be built to stand independently. The modules can then be completed with MEP interior finishes, fixtures, and appliances. The Hawaii Film Studio, for example, used PMC to meet strict timeline and budget requirements. Other examples of permanent modular construction include healthcare facilities, hotels, schools, and restaurants.

Relocatable Buildings

Also known as portable buildings, RBs are partially or completely constructed structures that also abide by set building codes and are assembled in a controlled manufacturing facility through the modular construction process.

Relocatable buildings are made to be repurposed and transported to various building sites. They can be used for medical clinics, schools, sales centers, and construction site offices, among others.

The Differences Between Relocatable and Permanent Modular

1. Duration Of Use

Permanent modular structures are fabricated and installed for long-term use. They are designed to be durable, just like conventional buildings, and can last just as long (or longer) than traditionally-constructed buildings.

Relocatable buildings, on the other hand, are installed for a shorter intended duration; a few months or a year, for instance. They are also designed durable enough to withstand several relocations and installations.

2. Types of Materials Used

Because permanent modular structures are intended for longer use, they are typically constructed with wood, steel, and/or concrete. Relocatable buildings, on the other hand, are usually made of wood to make them lightweight and easier to transport and reinstall.

3. Building Purpose

Permanent modular buildings are designed to remain in one location for an extended period of time.

Temporary modular buildings are ideal for situations that demand quick construction and future relocation and repurposing. They are mostly built to offer temporary housing such as, construction site offices, or mobile showrooms, as well as for some commercial purposes.

4. Architecture

When it comes to architecture options, temporary modular structures offer less design and layout choices. They also offer fewer options for customization.

Though the architect's plans for PMC must be settled well before construction begins, permanent modular buildings offer nearly endless options. From the addition of lobbies to elevators and stairwells, these structures offer construction engineers and consumers alike countless design possibilities.

5. Construction Duration

While the duration of construction will depend on the scope of work, relocatable buildings have the potential to be on-site and ready to use within weeks.

On the other hand, permanent modular buildings may take months or more to construct and assemble on-site based on the structure's size and design. Despite the differences between the two types of modular construction, both types offer owners many benefits. The benefits include: less material waste, faster completion of projects because of indoor construction, safer construction, and a quicker return on investment. For a complete list of the Modular Building Institute's PMC and RB manufacturers, click here.

More from Modular Advantage

Inside the Construction of 355 Sango Court

This year’s winner for Best of Show for Permanent Structures is 355 Sango Court, a 105,818 square foot affordable housing development manufactured by Nampa, Idaho based Autovol. The project team also included Prefab Logic for module design, Nibbi Brothers as the general contractor, Acc U Set Construction as the modular installer, and the overall project design was by David Baker Architects and DCI and Fard.

Aster Place by ROC Modular

Aster Place, a supportive housing building in Richmond, British Columbia, Canada, won the Best of Show Award and Honorable Mention for relocatable structures in the social and supportive housing category at this year’s World of Modular conference.

Looking Back at the 2024 World of Modular

On March 18-21, the Modular Building Institute presented its 41st annual
convention and tradeshow, hosted again at the luxurious the Rosen Shingle Creek in Orlando, FL. Nearly 1,500 attendees from around the world gathered to learn, network, and find ways to expand both their businesses and the industry at-large.

Touring Japan’s Offsite Construction Industry: An Interview with James Haas, Offsite Construction Sales Manager for Nichiha

Nichiha USA, a premier provider of building envelope solutions and member of the Modular Building Institute (MBI), recently partnered with MBI for a trip to Japan to visit the Nichiha home office in Nagoya as well as several other offsite manufacturers around the country. Besides learning about different offsite building methodologies and systems, the trip was an excellent chance for both MBI and Nichiha to create closer ties with potential industry partners in Japan.

Modular Multi-family Construction: A Field Study of Energy Code Compliance and Performance through Offsite Prefabrication

Prefabrication in a factory setting may improve the performance of modular buildings compared to traditional site-built buildings. To validate this premise, the U.S. Department of Energy (DOE) funded a 3-year study from 2020-2023 comparing the energy performance of more than 50 modular and site-built multifamily buildings under construction in Los Angeles, San Francisco, Philadelphia and Seattle.

Inflation Comes in Hot to Begin ’24

Last year was a shockingly good one for the U.S. economy, at least relative to expectations. Coming into 2023, the conventional wisdom was that near-term recession was inevitable in America. In the face of belligerent excess inflation (above the Federal Reserve’s 2 percent mandate), monetary policymakers began ratcheting interest rates higher in March 2022. That process continued throughout the balance of the year and into 2023.

A Huge Win for the Modular Construction Industry in Massachusetts

In early February, 2024, the Massachusetts Board of Building Regulations and Standards (BBRS) released its proposed 10th Edition building codes. This draft included several amendments targeting modular construction that would have created an extremely difficult environment for the entire modular industry and could have eliminated the industry entirely in the state.

FEMA Announces Hawaii Housing Plan Using Modular Construction

Utah becomes the second state in the country, following Virginia, to fully adopt ICC/MBI standards 1200 and 1205. MBI will continue to work with leadership in Utah to implement the new program.

Supply and Demand: Solving Canada’s Housing Crisis One Relocatable Housing Unit at a Time

Not only do Moda Modular’s repurposed employee housing solutions cut the emissions related to construction down to nearly zero, but they also keep building materials that are often not biodegradable from slowly decaying in storage facilities.
It’s the classic environmental mantra of reduce, reuse, and recycle, scaled up and applied to building after building.

ICC/MBI Standards 1200 & 1205 Provide Foundation for Utah’s First-Ever State Modular Program

Utah becomes the second state in the country, following Virginia, to fully adopt ICC/MBI standards 1200 and 1205. MBI will continue to work with leadership in Utah to implement the new program.