Electric operation for movable walls
Linear load of 45 kg/m2 and the 25 kg regulatory threshold: why motorise
Motorising a movable wall transforms the operating equation of a reconfigurable office floor. A 100 kg acoustic panel deploys in 60 to 120 seconds when electric, compared with 8 to 12 minutes manually. The linear mass of an Rw 52 dB partition reaches 45 kg/m2, that is 1,600 kg for 36 m2 deployed, a load well beyond the 25 kg permitted per operator under R4541-1. Kytom, founded in 2006, integrates this motorisation on 35% of its movable partition projects from its 11 agencies in France and Spain, with a guaranteed Rw of 50 to 59 dB according to NF EN ISO 10140. The initial 30 to 45% additional cost pays off in 3 to 4 years from 5 weekly reconfigurations.
An acoustic movable wall weighs 45 kg/m2 on average to achieve an Rw sound reduction of 50 to 59 dB. On a partition of 12 linear metres and 3 metres in height, the total weight exceeds 1,600 kg, split into 12 panels of 130 to 140 kg. Manual operation occupies one operator for 8 to 12 minutes per cycle, with repeated load handling.
Three regulatory references shape the decision:
- Manual handling: limited to 25 kg per person without a formalised risk assessment.
- MSD prevention: motorisation recommended beyond 100 kg per panel to prevent back and lower-back disorders.
- NF S 31-080: target Rw of 38 dB in direction for a standard meeting room, 52 dB for enhanced confidentiality.
The 4 types of spaces that are most often motorised are modular conference rooms, training centres, company restaurants reconfigured 5 to 15 times per week, and divisible auditoriums. Motorisation becomes profitable from 3 weekly reconfigurations, a threshold observed on delivered projects.
Manual vs motorised comparison across 180 projects delivered between 2019 and 2023
Across 180 movable wall projects delivered by Kytom agencies, the performance gap between manual operation and electric motorisation is measured through four operational indicators.
| Indicator | Manual | Motorised | Variation |
|---|---|---|---|
| Cycle time, 36 m2 | 10 min | 90 s | -85% |
| Rw measured on site | 48-50 dB | 52-54 dB | +4 dB |
| MSD risk | High | Near zero | -90% |
| Room usage rate, 6 months | Baseline | x 1.8 | +80% |
The time gain frees up 3 to 5 hours per week for office managers on highly modular sites. Acoustic comfort stays constant at Rw 54 dB thanks to motorised perimeter seals that descend with a constant pressure of 200 to 300 N/m, compared with a 4 to 6 dB loss observed on poorly locked manual operations, that is 25% of cases according to field measurements. Eliminating load handling reduces exposure to musculoskeletal disorders by 90%.
The Kytom method in 5 steps over 12 weeks, from laser survey to training of in-house leads
The process unfolds over an average lead time of 12 weeks between signing and commissioning, with a single project manager from the DCE to delivery.
- Floor audit: laser survey, verification of the upper slab with a minimum admissible load of 250 kg per linear metre, recommended clear height of 3.20 m.
- Acoustic sizing compliant with NF DTU 35.1 (demountable partitions) published on 7 February 2015, classification index P 24-802-1-1, target Rw of 52 dB minimum for confidential rooms.
- Choice of motorisation: 24 V motorised carriages, speed 0.15 m/s, wired control or encrypted secure radio.
- Electrical integration: dedicated 230 V supply compliant with NF C 15-100, connection to SSI and BMS, management of fire-stop interlocks.
- Commissioning: 10 test cycles, training of 2 to 4 in-house leads, handover of the DOE and annual preventive maintenance contract.
Three guarantees cover the service: ten-year warranty on the structural works and supports, manufacturer’s 24-month warranty on the motorisation and control electronics, acoustic commitment with Rw measured on site after installation.
Decision table by usage frequency and space type
The choice between manual operation and electric motorisation depends on the actual usage frequency, the deployed surface area, and the acoustic criticality. The following grid summarises the recommendations drawn from delivered projects.
| Configuration | Reconfig. frequency | Surface | Recommended solution | Payback |
|---|---|---|---|---|
| Meeting room 24 m2 | < 2 / week | 24 m2 | Reinforced manual | Not applicable |
| Training centre | 3 to 5 / week | 36 to 60 m2 | Motorisation | 4 years |
| Company restaurant | 5 to 15 / week | 60 to 100 m2 | Motorisation | 3 years |
| Divisible auditorium | Daily | > 80 m2 | Motorisation + SSI | 2 to 3 years |
| Confidential board room | Variable | 30 to 50 m2 | Motorisation Rw 54 dB | Depending on use |
The payback thresholds factor in the initial 30 to 45% additional cost, that is 250 to 400 EUR excl. tax per extra m2 on a standard movable wall at 900-1,200 EUR excl. tax/m2. For a 36 m2 partition, the gap represents 9,000 to 14,000 EUR excl. tax, including motorisation, dedicated 230 V supply and radio control.
Three structural constraints to anticipate: slab, maintenance, manual backup
Motorisation imposes 3 constraints integrated from the DCE phase by the Kytom teams.
- Linear load on the upper slab: 200 to 300 kg per linear metre, which excludes 15% of older office floors without prior steel reinforcement. The structural audit adds 2 to 3 weeks to the schedule.
- Mandatory annual maintenance: 1.5 to 2.5% of the purchase price, that is 600 to 1,200 EUR excl. tax per year for a 36 m2 partition. Without this servicing, service life drops sharply.
- Manual emergency release mode: required in the CCTP to allow closing in the event of a 230 V power cut. Kytom makes it systematic, in line with smoke extraction requirements for category 1 to 4 public buildings (ERP).
Two scenarios call for a specific study: a height greater than 5 metres with deflection calculation at the ceiling and IPN reinforcement, or a surface greater than 80 m2 with fire compartmentation and SSI interlock. In both configurations, the average lead time rises from 12 to 16 weeks.
SSI, BMS integration and 230 V supply compliant with NF C 15-100
The electrical integration of a motorised movable wall involves three distinct technical interfaces. The dedicated 230 V supply complies with NF C 15-100, with a 16 A thermal-magnetic circuit breaker and 30 mA differential protection. Routing the cables in the ceiling must preserve the acoustic continuity of the plenum, a recurring point of vigilance: a poorly sealed sleeve cuts the Rw by 3 to 5 dB.
The SSI connection governs the fire-stop interlock for public buildings (ERP). In the event of a general alarm, the partition folds back or releases according to the safety strategy defined in the CCTP. The BMS receives status feedback (position, motor fault, completed cycles) via BACnet or Modbus protocol, which enables predictive maintenance monitoring.
Operator control comes in three formats: wall-mounted wired panel, encrypted radio remote, tablet interface for highly modular sites. Kytom trains 2 to 4 leads per site with the handover of a simplified operating manual and an annual preventive maintenance contract covering the 10,000 cycles stated by manufacturers.
Frequently asked questions
What is the additional cost of electric operation compared with manual?
The additional cost ranges from 30 to 45% of the price of an equivalent manual movable wall, i.e. an extra 250 to 400 EUR excl. VAT per m² on a standard movable wall at 900–1,200 EUR excl. VAT/m². For a 36 m² partition, the difference amounts to 9,000 to 14,000 EUR excl. VAT, including motorisation, dedicated 230 V supply and radio control.
