6 similarities and differences between modules and containers (pt 2)

In a previous post, we dealt quite generally with the similarities and differences between modules and containers. Today, it is time for a more detailed comparison, taking into account some structural and technical issues. It is worth reading to better understand the advantages of modular construction and, if you are planning an investment, to make the best decision.

Comparison of module and container dimensions

Here the issue is simple: modules can be much larger than containers. The size of modules is determined solely by transport constraints, whereas containers have dimensions that are not modifiable in their class. The size of the individual modules is decided by the designer and is only limited by transport requirements. The usable area of a single modular structure can be more than 100 m2 and a container structure a maximum of around 35 m2.

Modular structures - more solid and durable - are heavier: the weight of their skeleton can reach 15 tonnes, while that of containers is 3 tonnes. A simple comparison: Modules can be used to construct buildings with several tens of storeys, while the capabilities of containers are limited to three storeys, which results, among other things, from Polish construction law and fire safety regulations. On the other hand, containers are an excellent choice if the object of the investment is to build a kiosk on the beach or a commercial box.

Below you will find an overview of the gross dimensions of modules and containers used in construction:
Dimensions of building modules

As mentioned earlier, the dimensions are limited purely for transport reasons. Modules are transported individually, i.e. one module is allowed to be transported on one semi-trailer...:

Length
Width
Height
up to 20 m
up to 5.5 m
up to 4.2 m

Depending on transport conditions, larger modules are also possible.
Dimensions of building containers

Foot length
Length
Width
Height

As can be seen, the use of a container structure makes it impossible to design a ceiling height other than 2.6 m. Moreover, the fixed width makes it difficult to build rooms with a width that differs from a multiple of the width of a single container.
Comparison of module and container dimensions
Comparison of module and container dimensions
Differences in roofs, load-bearing capacity and aesthetics

Both modular and container buildings can be covered with roofs of any material, in any shape - for example, flat or gabled. A modular building can be designed to fit in perfectly with its surroundings, whether it is a modern housing estate or a historic district. The situation is different with containers: in many places it will be difficult or even impossible to obtain planning permission using them.
High load capacity an advantage for the modules

However, the structures differ in terms of load-bearing capacity, which is significantly higher for modular buildings. What is more, it can also exceed the strength of a traditional structure. The steel skeleton of the modules can cope better with snow, and the structures made from it also excel over containers in terms of aesthetics. The tallest building to date, erected using steel-framed modular construction technology, is as high as 32 storeys. The modules are constructed taking into account the location of the building and the load norms (wind and snow) in the respective region of the world. Structural constraints do not always allow container structures to be adapted to these standards. Installations that cannot be accommodated in the walls in the case of containers can also be a problem. They will therefore either be located indoors, limiting usable space and reducing the aesthetics of the interior, or outdoors, visible to the environment. However, the rather heavy modules will not perform as well as containers in the role of temporary buildings that frequently change location, such as back-of-house facilities or pop-up shops.

Comparison of insulation, fire resistance and acoustics

Not everyone knows that modular structures have excellent insulation. As a result, in modules it is much easier to approach a zero-energy specification and increase the passivity factor. Containerised construction does not have these capabilities - if it is to be used in cold seasons, the walls and floors need to be additionally insulated. The prevalence of modules in this element is driven by modular walls with a bridgeless construction, filled with mineral wool. Containers are usually sandwich panel panels, sometimes with wool. The floors in the modules are made of panels with increased load-bearing capacity and acoustic insulation and with thermal insulation in the form of closed-cell polyurethane foam, wool or other high-quality material. The modules are joined by screwing them together horizontally and vertically, while the containers are only joined horizontally. The tightness of the joints in the modules is checked for compliance with EN 13829, while the container joints are sealed with silicone or bitumen compound and the water must be drained to the outside with gutters.
What is the fire resistance of modular buildings and containers?

The steel construction of modular buildings perfectly satisfies fire protection requirements. What is more, in many cases the structures are protected according to higher classes than the legal requirements. The use of non-combustible walls and the properties of the structural steel used in the modules are of great importance here. Container buildings are also built to the appropriate standards.
Sound insulation for modular buildings

It is also important to bear in mind the very good acoustic performance of modular buildings, which are designed for bi-directional noise reduction. During the design phase, both the location and functional layout of the building are considered, as well as the acoustic properties of the structure itself and the materials for the building envelope. Obtaining adequate acoustic insulation in containers is made considerably more difficult due to the use of sheet metal in the wall construction and the way the containers are joined together.
Comparison of insulation, fire resistance and acoustics
Comparison of insulation, fire resistance and acoustics
Modules fear corrosion

Weather conditions have no effect on the welded steel structure of the modules. The steel profiles are shot-blasted before welding and then painted with anti-corrosion coatings. As this is all inside and not outside, the structure is not affected by precipitation or moisture. This is different for containers, whose structures have to be mechanically rusted and renewed over time.
Modules fear corrosion
Modules fear corrosion
Differences in purpose

Modular structures are fully compliant with the standards applicable to public buildings. These are much more difficult for containers to meet, as this requires modifications to their construction. Modules are therefore suitable for the construction of permanent buildings such as hospitals, schools, kindergartens, canteens or hotels - regardless of their size. Containers, on the other hand, are more suitable for building back-up facilities, temporary structures, commercial pavilions and rooms in production halls.
Differences in purpose
Differences in purpose
Summary

Modular and container construction offers an alternative to the traditional erection of concrete or brick buildings. When planning an investment, the pros and cons of each option should be carefully weighed, taking into account both their advantages and disadvantages. Much depends on the purpose of the building in question, its surroundings and the financial assumptions of the project. When building smaller structures of a temporary nature, it is worth doing some research into the container market. If you want to build something that will last for years, a sensible decision would be to choose modular construction.