Assuming a total floor area of 1,800 tsubo (fixed), we provide a detailed comparison and explanation between "2-story / 3-story" buildings, which minimize the total investment including land price, and "4-story / 5-story" buildings, which can minimize the site area to the utmost limit.
This will clarify the "surge in structural costs" and "operational precautions" specific to high-rise floors (4th and 5th floors), where the floor area per story becomes narrower.
* Calculated with a fixed total floor area of 1,800 tsubo. The construction unit price per tsubo reflects the recent surge in material and labor costs (S structure / system architecture / standard specification). Land prices are estimated based on standard industrial zones in Sagamihara City, etc. (500,000 yen per tsubo, building coverage ratio 60%, assuming the securing of truck berths).
| Number of Floors | 1-Story (Single-story) | 2-Story | 3-Story | 4-Story | 5-Story |
|---|---|---|---|---|---|
| Building Area (1st floor single level) | 1,800 tsubo | 900 tsubo | 600 tsubo | 450 tsubo | 360 tsubo |
| Construction Unit Price per Tsubo (Approx.) | 650k - 750k yen | 750k - 850k yen | 850k - 950k yen | 950k - 1,100k yen | 1,100k - 1,250k yen |
| [A] Building Main Body Construction Cost | Approx. 1.26 Billion Yen | Approx. 1.44 Billion Yen (vs Single-story +14%) |
Approx. 1.62 Billion Yen (vs Single-story +28%) |
Approx. 1.85 Billion Yen (vs Single-story +46%) |
Approx. 2.11 Billion Yen (vs Single-story +67%) |
| Required Vertical Transport Equipment | Not required | Vertical Transport Machine 1-2 units (Approx. 20M - 40M yen) |
Vertical Transport Machine 2 units + Elevator |
Vertical Transport Machine 3 units + Emergency EV |
Vertical Transport Machine 3-4 units + Emergency EV |
| [B] Additional Cost for Transport/Disaster Prevention Equipment | 0 Yen | Approx. 0.04 Billion Yen | Approx. 0.08 Billion Yen | Approx. 0.12 Billion Yen | Approx. 0.16 Billion Yen |
| [Total Construction & Equipment (A+B)] | Approx. 1.26 Billion Yen | Approx. 1.48 Billion Yen | Approx. 1.70 Billion Yen | Approx. 1.97 Billion Yen | Approx. 2.27 Billion Yen |
| Required Site Area (Approx.) | Approx. 3,000 tsubo | Approx. 1,600 tsubo | Approx. 1,100 tsubo | Approx. 850 tsubo | Approx. 700 tsubo |
| [C] Land Purchase Cost (500k yen/tsubo) | 1.50 Billion Yen | 0.80 Billion Yen | 0.55 Billion Yen | 0.425 Billion Yen | 0.35 Billion Yen |
| [Total Investment Amount (A+B+C)] | Approx. 2.76 Billion Yen | Approx. 2.28 Billion Yen | Approx. 2.25 Billion Yen | Approx. 2.395 Billion Yen | Approx. 2.62 Billion Yen |
Looking only at construction costs, a single-story building is the cheapest. However, when looking at the total investment amount of "land + building," the result is that a 2-story or 3-story building yields the lowest total cost (break-even point).
Compared to a single-story or 2-story building, the construction unit price for 4-story and 5-story buildings jumps by nearly 1.5 to 1.7 times. The main factors are as follows:
To support the load of 4 to 5 floors (floor load of 1.5t/㎡ or more) and the horizontal forces during an earthquake, the amount of steel for pillars and beams increases sharply. Additionally, the length and thickness of ground improvement piles driven deep into the ground increase, causing foundation construction costs to skyrocket.
To prevent cargo transport to upper floors from stalling, it is necessary to install 3 to 4 vertical transport machines (VIF) (approx. 15 million to 20 million yen per unit). Furthermore, the installation of an emergency elevator (starting from approx. 30 million yen) becomes mandatory under the Building Standards Act.
If a 4-story or 5-story building is chosen for a scale of 1,800 tsubo total floor area (medium-scale logistics facility), risks arise not only in costs but also in operations.
The area per floor becomes narrow, ranging from 360 tsubo (5th floor) to 450 tsubo (4th floor). If "3 vertical transport machines," "elevators," "emergency stairs," "toilets/break rooms," and "aisles" are arranged within this narrow floor, the "effective storage area" where goods can actually be placed is reduced by over 20% per floor.
During shipping peaks, vertical movement of cargo concentrates between the truck berths on the 1st floor and the 4th/5th floors, making it easy for cargo waiting (congestion) to occur in front of the transport machines.
This offers the best balance between the increase in construction costs and the reduction in land prices, keeping the total investment amount (approx. 2.25 billion to 2.28 billion yen) to the lowest level.