Accessibility (one-sided, two-sided, three-sided, four-sided) in warehouse logistics

Definition and relevance of drivability in logistics

In the context of logistics real estate, the term accessibility (often also called delivery) describes the structural design of the access and exit routes as well as the arrangement of the loading gates (docks) on the building. It defines how trucks can approach the building, dock and handle goods.

For warehouse and contract logistics, this is not just a question of architecture, but a strategic process decision. The type of accessibility dictates the material flow inside the hall. While pure storage often get by with a few gates, transshipment/cross-docking operations require maximum door densities and flexible access roads.

The basis: One-sided accessibility (The classic warehouse)

One-way delivery is the standard for classic storage warehouses and distribution centers with low to medium turnover rates. Here, all loading gates are located on a single long side of the hall (the so-called "dock side").

• Area of application: Long-term storage, spare parts logistics, e-commerce with a low proportion of fast-moving items.
• Advantage: Cost-efficient in construction, as less yard space is required. The back of the hall can be adjacent to other buildings or used for expansion.
• Disadvantage: The material flow takes place in a U-shape (incoming and outgoing goods on the same side). In the event of high volumes, this can lead to intersection traffic inside and traffic jams on the forecourt.

Fact check: In modern standard logistics properties ("big box"), a ratio of 1 door per 800 to 1,000 m² of hall space is often  sought. In the case of purely one-sided traffic, this density is often the maximum.

Two-way accessibility: cross-docking and flow

Two-way accessibility is the "supreme discipline" for efficient supply chains and is often cited synonymously with the ability to cross-dock. In this case, the gates on the two long sides of the building are directly opposite each other or staggered.

• The I-point flow: Goods arrive on side A (incoming goods), are sorted in the hall (often without storage on the shelf) and leave the hall on side B (outgoing goods). The material flow is linear.
• Importance for contract logistics: Service providers who have to guarantee fast handling cycles (e.g. for food retailing or automotive JIT) prefer two-way delivery.
• Property value: Properties with two-sided accessibility have a higher third-party usability, as they can be used both as a pure warehouse and as a transshipment hall.

Three- and four-way accessibility: high-speed terminals

If speed is the only criterion, three- or four-way bids come into play. These designs are rarely found in classic logistics properties, but almost exclusively in CEP service providers (courier, express, parcel) or in freight terminals.

• Three-sided: Often arranged in a U-shape or T-shape. Enables an extremely high door density on a small footprint.
• Four-sided (island location): The building stands freely on the property and is equipped with gates all around.
• Disadvantage: These properties are "Special Purpose Properties". Racking is difficult because there is hardly any wall space. A conversion (e.g. to a pure pallet warehouse) is often uneconomical, which increases the investment risk.

Technical requirements: courtyard areas and gate dimensions

Theoretical drivability is of no use if practice fails. The following data is essential in the valuation of logistics real estate:

• Yard depth: For a standard articulated truck (40t), a yard depth (distance from ramp to fence/boundary) of at least 35 meters is  required. Modern standards often go up to 40 to 45 meters in order to allow long trucks (gigaliners) to maneuver safely.
• Concrete slabs: The area in front of the gates (approx. 20-25 meters) must be concreted to withstand the static pressure of the supporting trailers (bridges); Asphalt would sink in here in summer.
• Level gates vs. ground-level gates: A healthy ratio is important. While docks (with dock levellers) are essential for trucks, every hall also needs ground-level sectional doors (jumbo doors) for forklift trucks or sprinters to enter the hall.

Q&A: Frequently asked questions from practice

Question: What influence does drivability have on operating costs? Answer: Two-sided accessibility increases the cost of land, as more sealed area is required for the truck yard (less built-up space per m² of land). However, internal process costs often fall significantly due to shorter distances and less forklift traffic.

Question: Does "a lot helps a lot" apply to the number of goals? Answer: Not necessarily. Too many doors reduce the shelf space on the outer walls and increase maintenance costs (maintenance of dock levellers and dock seals). A ratio of 1 gate per 500 m² is considered very high (cross-dock), 1 per 1,000 m² is standard.

Question: What does "dovetail delivery" mean? Answer: This is a special form of ramp arrangement (sawtooth profile) that allows trucks to dock at an oblique angle. This saves space in the courtyard depth, but is more challenging for the drivers when manoeuvring.

Strategic importance for investors and developers

From the point of view of logistics real estate development, accessibility is a balancing act between space efficiency (GRZ – floor space number) and user-friendliness. Two-sided accessibility requires larger plots of land. Since logistics space is scarce in Germany ("shortage of space"), construction is often only one-sided for cost reasons. For investors, the following applies: A property that at least offers the option of  a two-sided tender (e.g. through "knock-out panels" in the concrete wall at the back, where gates can be retrofitted later) is much more valuable and future-proof.

Conclusion: The right choice determines the utility value

Accessibility is not a static feature, but a dynamic factor in logistics processes.

• For contract logistics companies , flexibility (two-sidedness) is the trump card in order to be able to meet changing customer requirements.
• For owner-occupiers (e.g. trading companies), a one-sided hall optimized for storage density can be the most economical solution.
• Handling companies absolutely need through-loading concepts (cross-dock).

Anyone planning or renting a logistics property today should not only look at the rental price per square metre, but also check whether the drivability physically allows the targeted handling speeds at all.