How Volumetric Steel Modules Assemble into Multi-Storey Apartments
Combining living spaces, wet pods, stair cores, and acoustic decoupling across vertical stacks. Structural load transfer, fire compartments, and corridor integration up to 8 storeys.
1. From Single Modules to Multi-Room Dwellings
A common misconception is that a modular apartment must equal a single shipping-container-sized box. In reality, a modern 2-bedroom or 3-bedroom apartment is typically assembled from 2 to 4 volumetric steel modules side-by-side and end-to-end.
Structural perimeter steel moment frames allow wall spans between adjacent modules to be left completely open, creating expansive living-dining rooms up to 8 meters wide with uninterrupted ceiling lines and seamless hardwood or tile flooring installed across the module seams.
2. Double-Skin Acoustic & Fire Compartment Separation
One of the greatest engineering advantages of volumetric modular construction is inherent double-skin isolation. When two modules are placed side by side, there is not one party wall, but two independent structural steel stud walls separated by a physical air cavity and acoustic dampening insulation.
Similarly, the ceiling of the lower module and the floor chassis of the upper module form an acoustically decoupled double-slab assembly separated by high-density neoprene pads. This achieves laboratory-tested sound reduction values exceeding 58–62 dB (Rw + Ctr) and EI 60 to EI 90 certified fire resistance between independent dwelling units.
3. Cores, Podiums and Vertical MEP Riser Integration
In multi-storey buildings over 4 storeys, lateral wind and seismic stability are frequently resolved using a hybrid structural approach: a slip-formed concrete or hot-rolled steel core housing high-speed elevators and fire egress stairs, tied horizontally to the volumetric module stack at each diaphragm level.
Common corridors and vertical MEP risers are aligned vertically across all floors. During installation, pre-plumbed module wet pods connect into the central building riser within minutes via gasketed push-fit acoustic couplings, dramatically accelerating building commissioning.
Structural & Performance Comparison: Modular vs. Traditional Multi-Unit Buildings
Construction Speed (40-unit building)
Structural Dead Weight
Acoustic Decoupling (Party Walls)
Site Waste & Disturbance
| Metric / Performance | Traditional Concrete Frame | SERMODULA Volumetric Steel Modular |
|---|---|---|
| Construction Speed (40-unit building) | 18 – 24 months on-site civil works | 6 – 8 months total (concurrent factory + site works) |
| Structural Dead Weight | 1,200 – 1,500 kg per m² of gross floor area | 350 – 450 kg per m² (saves up to 40% on foundation costs) |
| Acoustic Decoupling (Party Walls) | 48 – 52 dB (depends heavily on on-site plasterer craftsmanship) | 58 – 64 dB (inherent double-wall and neoprene resilient pads) |
| Site Waste & Disturbance | High dust, noise, skip waste (10-15% material loss) | Minimal disturbance, zero wet mortar, 90% fewer delivery trucks to site |
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