About ExoSett
ExoSett and conventional modular construction
Conventional modular construction and ExoSett both use factory-produced volumetric accommodation units, but they organise the relationship between accommodation, structure, access and services differently.
ExoSett is intended to place removable accommodation cassettes within an independent structural frame, with an associated service frame providing access, circulation and utility infrastructure. Conventional modular construction includes many different systems; this comparison describes common approaches rather than every modular building.
The central distinction
Separate roles within one building system
ExoSett separates the accommodation cassette, the accommodation frame that carries structural loads, and the associated service frame that supports access, circulation and utilities.
The accommodation frame is intended to remain structurally capable whether a cell contains a cassette or is temporarily empty. This makes change a defining design condition rather than an exceptional intervention.
At a glance
A comparison of the approaches
| Question | Conventional modular construction | ExoSett |
|---|---|---|
| What provides the principal structural support? | Modules may be load-bearing, stacked or combined with another structural system, depending on the design. | An independent accommodation frame is intended to carry the structural loads. |
| Can one accommodation unit be removed independently? | This depends on the system and may require substantial temporary work or disturbance. | Independent cassette removal and replacement is a central design objective. |
| What happens when a unit is absent? | The consequences depend on whether the module contributes to structure, enclosure or services. | The cell may remain empty while the surrounding frame continues to stand. |
| Where are access and circulation provided? | They may be incorporated into modules, corridors, cores or separate structures. | An associated service frame provides continuing access and circulation. |
| Where are utilities routed? | Services may pass through modules, voids, corridors or dedicated service zones. | Accessible service routes and interfaces are all routed though the service frame and are intended to remain available as cassettes change. |
| Can the building expand or contract? | This may be possible, depending on the original system, but can require substantial reconstruction. | Expansion, contraction and reconfiguration are intended lifecycle capabilities. |
| Can units be reused elsewhere? | Often, subject to design, condition and transport constraints. | Reuse and relocation are explicit objectives for cassettes and frame components. |
| Is the system commercially proven? | Many established systems have completed buildings and established supply chains. | ExoSett is currently a developing concept undergoing design and engineering work. |
Structure
Cassettes hosted by an independent frame
Many modular systems use modules as part of their structural arrangement. Others use separate frames, podiums, cores or hybrid structures. Conventional modular buildings do not all rely entirely on stacked modules.
ExoSett’s specific proposition is that accommodation cassettes should not be required to carry the building independently or support cassettes above them. Loads are intended to pass through a structure assembled from columns, beams and frame nodes, with temporary bracing used where the construction or alteration sequence requires it.
Installation and removal
Change requires a controlled process
Removing a cassette is not simply the reverse of placing it by crane. The cassette must be disconnected, supported, moved clear of the frame and transferred safely while the surrounding building remains protected and operational constraints are managed.
ExoSett anticipates controlled installation and removal using temporary equipment including an installation frame, a cassette jig and, where required, a frame jig. Their detailed forms, sequences and limits remain subjects of design and engineering work, rather than final engineering solutions.
Access and services
Infrastructure that remains available
The service frame is an essential associated part of an ExoSett building. It is intended to preserve access and circulation when cassettes change, while supporting the escape routes required by the particular building design.
Defined service routes and service interfaces are intended to keep utilities accessible and allow maintenance without opening occupied accommodation. Access bridges may connect the service frame to individual cassettes while accommodating the separation between the two structures.
Change over time
Adapt the accommodation while retaining useful infrastructure
ExoSett is intended to support replacement of damaged or obsolete cassettes, changes in dwelling or room size, and a changing accommodation mix. The evolving hotel and old prison stories explore how accommodation might change without replacing an entire building.
Capacity could be added through additional floors or reduced through downsizing, subject to the design and engineering of a particular project. Cassettes and structural components are intended to be reusable where their design, condition, transport and regulatory context permit.
Accessible, separable infrastructure is also important to this adaptability. The simple utilities story illustrates one possible approach to changing service connections over time.
Important qualification
What ExoSett does not claim
ExoSett is a developing building-system concept, not a proven commercial construction system. Detailed structural engineering and the practical methods needed to realise the system are still being developed.
Suitability will depend on site, height, loading, fire, acoustic, environmental, regulatory and operational requirements. Each implementation would need project-specific design, engineering and approval.
This comparison does not claim that ExoSett is universally superior. Conventional modular systems may be preferable where rapid delivery, established certification, standardised procurement or an existing supply chain is the main priority.
In summary
A building system designed around continued change
ExoSett is not defined merely by using removable cassettes. Its defining proposition is the combination of removable accommodation cassettes, an independent accommodation frame and an associated service frame intended to allow the building to change over time.