A site should offer good visibility and access, and have well-established, drive-by traffic flow. As the awareness of self-storage grows, this visual presence will play a more important role in fulfilling occupancy goals, as well as help reduce marketing and advertising budgets. However, it is not always possible to find the right site with an acceptable building. For the prospective owner, when an existing building is not suitable, two choices are available: find another site, or construct a new building.
The majority of European operators will simply look for another site rather than build new, assuming this is a cheaper and quicker option. The main exceptions to this rule are Shurgard Self-Storage SCA in Europe, Big Yellow Self Storage in the United Kingdom, and Dein Lager Self Storage in Austria. Martin Gerhardus of Dein Lagerraum has five sites in Vienna and one in Munich, of which five are new builds and only one is a conversion.
Building a facility from the ground up offers owners the opportunity to design according to their needs. With a goal of achieving a good rentable-yield ratio, the facility should offer drive-thru and direct access units. The optimum size seems to be about 80,000 gross square feet, which provides approximately 55,000 to 60,000 square feet of rentable area.
Storage buildings will vary from country to country in accordance with traditionally accepted construction methods. In the United Kingdom, the standard design is a heavy-steel, portal-frame assembly and steel composite panel cladding, with individual floors independent of the main structure. By keeping the floors free-standing, local authority rate charges can be minimized. These floors are typically constructed using square, hollow-section columns that support a steel framework of cold-rolled sections and are decked with compressed chipboard. This style makes the building suitable for any use should the self-storage project fail. New builds in other areas of Europe could be constructed with concrete columns, or integrated concrete floors with steel, masonry or concrete panel walls.
Due to the additional time it takes to obtain local-authority approvals for a new build, it is essential the construction timetable is kept to a minimum. It is not unusual for the main-building construction and internal fitout to be handled under separate contracts. This minimizes the higher supervision and preliminary costs charged by the primary contractor, which are not usually required for smaller, internal fit-out operations.
Typically, a primary contractor is responsible for site clearance; foundations, footings and services; building frames and cladding; main doors; lift shafts; and ground work and landscaping. A secondary supply company installs the mezzanine floors and stairs, internal- partition fit-out, office, internal security gates, lifts, electrical smoke-detection and alarms, access control and CCTV. It is common for all these trades to work together on an overlapping schedule to complete the work in the shortest time.
Conversion construction is similar to the second or interior phase of a new build, but normally also requires repair work. The important elements for determining the viability of a conversion and current state of repair include the ground-floor footprint, wall heights (to determine number of floors), the means of access from the roadway, and potential escape routes from the building. Once these have been determined, the existing floor structure must be tested for its capacity to sustain the point-load weights of the mezzanine columns. This can be done with either a core sample or from original design details.
With the options available for internal-partitioning systems, it is easy to make the inside of an existing building look like new. There are excellent lightweight, integrated building systems specifically designed for the self-storage market. These are being used for single-level, detached, drive-up units, which are a popular way of filling vacant car-parking areas. These systems have been successfully used for multilevel facilities in Austria, Scandinavia and the United Kingdom.
Often, buildings selected for self-storage conversions were used for some form of storage and do not normally require planning permission. However, approval will be required if the building exterior is to be altered, especially where signage is involved. The acquisition of a site for a new building will always be subject to planning approval.
Permits and Regulations
Whether a facility is a new build or a conversion, all work is subject to building-control approval. Requirements apply to all structural elements, which must be detailed—from the slab design to roof flashings. Also important to building control are fire regulations, which not only vary from country to country but from region to region. In the United Kingdom, emphasis is on protection of structures, whereas other countries are more concerned about smoke extraction so people can easily exit the building and firefighters can see to fight the fire.
A typical mezzanine-floor, fire-protection system includes a fire ceiling—which can be a lay-in grid or fixed-plasterboard design—under the steel work. Columns are covered in a bespoke casing, which is generally galvanized plate with rock wool adhered to the inside. The ceiling is then sealed to the casings and building walls to create a complete, enclosed compartment. The stairs are enclosed in fire-proof pods, usually constructed from lightweight stud sections and plasterboard.
The alternative method is to have no structural fire protection but provide a means of smoke extraction. Rolf van Berkel of Kubus Mini Opslag in Holland is considering the installation of metal perforated plates to the corridor sections of the mezzanine floors, which will allow the smoke to pass through. These corridors will have to be positioned under the main extraction vents in the roof. Although this is probably a cheaper option, it may come at the expense of a good facility layout.
The allowable travel distances for evacuation due to fire will also affect the facility layout, and these distances vary from country to country. The extent to which they differ seems to depend on how well the self-storage industry is understood in the region. Where there is little knowledge of the industry and the exact fire category cannot be determined, a worse-case scenario will preside.
When the company first broached the subject with the fire-control board, Secur Self Storage in Germany was originally told it could have travel distances of only 10 meters. Distances between 15 to 25 meters are now generally accepted for a single exit or up to 50 meters if more than one exit is available.
Knowledge of self-storage is still scarce in the architectural, engineering and building-control professions in Europe. Educating owners’ design and planning teams as to what is acceptable and why and how other companies are overcoming issues is critical. Owners should seek knowledgeable builders that can use independent companies to process building-control certificates rather than work directly through local authorities. This will allow companies to become more experienced in the industry and argue a stronger case for realistic solutions to various building-code issues.
With the present uncertainty regarding regulations, many site and building-procurement deals must include “obtaining permissions” clauses to provide security for the buyer/owner. As the industry grows, variances to building codes will eventually be resolved, and it will be possible to have standard building models that can be easily constructed. Local building styles, techniques and products will always be preferred for exteriors, but interior products and layouts will become more standardized.
Dave Betts is the sales manager for Steel Storage Europe, a supplier of self-storage building systems and specialized products in the United Kingdom and Europe. He has been involved in the construction and sales sides of the industry for five years. Mr. Betts specializes in turnkey projects and new developments. For more information, call +44 (0)20 8744 9444; visit www.steelstorage.net.