By Kenneth Carrell

The design of a self-storage facilitys building envelope can save an operator a lot of money or cost him dearlyand not just in energy costs, but with customers. If a tenant goes into a typical storage building in the middle of summer, the temperature can be 10, 20 or even 30 degrees hotter than outside. In the middle of winter, if the building is not insulated, some customers items could freeze. If the building envelope is not properly sealed, rain and snow could get in, ruining stored goods and leaving you with a customer-service nightmare. However, with some planning before construction starts, you can eliminate some of these problems and create energy savings to boot.

The Building Envelope

The first place a self-storage owner can improve building efficiency is with the building envelope. The envelope comprises the roof, walls and floor. The typical self-storage facility has an exterior wall of masonry or thin metal; but the bulk of the exterior walls are the overhead doors, which are thin metal, typically without insulation. Everyone knows just how air-tight self-storage buildings are. Wind and dust get into units with impunity because the doors are rarely weather-tight.

If you live in a warmer climate like Southern California or Florida, you probably dont worry about heating and cooling your buildings. However, if you live in an area that gets snow and ice, you need to keep your buildings climate-controlled so customers' possessions are not damaged during the highs and lows of the weather. Planning ahead when it comes to insulating the building envelope is the first priority. Trying to do it after youve rented units can be a nightmarealthough it is possible.

First, you can insulate the walls and/or piers of the building. Depending on the wall construction, you can add insulation to the inside of the wall using a variety of methods. For masonry-block construction, you can add insulation to block cells that arent filled with grout. If necessary, you can add furring strips to the inside of the walls and batt or foam-board insulation between, and then cover them with metal or gypsum board. Masonry piers are fully grouted, so you can't add insulation to those cells, but you can definitely add it to the surface of the block.

Spray-foam insulation is another good option for block construction. If the building is metal constructed, it becomes much easier to protect the building, and you have an even wider selection for insulation.

Doors

Instead of installing the typical overhead door of thin uninsulated metal, use an insulated door that will not only boost the energy efficiency of the building but help keep out dirt and dust. The one major drawback to using a door that opens to the outside is once you open it, all of the conditioned air starts pouring out of the spacea sure-fire way to run up your energy bill.

One way to slow that down is to use a flexible air dam like they use in grocery stores. This will create a wall that will mitigate the loss. The other option is to build an insulated wall between the outside and interior units. Unfortunately, any unit thats accessed from the outside isnt conditioned, but its a small price to pay to keep your conditioned space.

Roof

Of course, the roof in a self-storage facility loses the most energy. You have a large expanse of thin sheet metal that radiates energy into the sky, so insulating it should be your top priority. Even in mild climates, there are benefits to insulating the roof. With the roof protected, the heat gain and loss will be slowed significantly.

The best method of insulating the roof is to use spray-on foam insulation like Icynene. Spray foam not only provides better and higher R-value insulation to the building, it fastens openings to give the building a more air-tight seal. You can always use standard batt or foam-board insulation. While its not cutting-edge technology, a little old-fashioned insulation can fit the bill.

Floors

The floor is another surface that can use energy. If your facility is in a cold climate and your building isnt heated, the ground underneath could freeze, which could make for a very cold environment. While heating the building could be expensive, it doesnt have to be. A storage facility only has to be kept in the low 50s, so a lot of heat isnt necessary. And there are a number of ways to generate heat without significant cost, such as solar panels.

Lighting

Lighting costs can also be significant. If a customer forgets to turn off the lights in a hallway and no one checks, they could burn all day, wasting a large amount of money. A simple fix is to install timers or motion-sensor switches for all the lights. If you use motion sensors, however, make sure you cover all the hallways. You dont want a customer who is in his unit to be trapped in a dark hallway when he leaves.

Another way to illuminate a building is to use natural light. Using a window or skylight can reduce your electricity costs. A storage building will need dual or triple glazing for windows and skylights to comply with current codes; but customers wont need to use the lights as often, and it will give the facility a better appearance and overall appeal.

Other than land costs, the building envelope is the most expensive part of a self-storage project at the beginning. However, on-going energy costs will quickly overshadow the building costs. By designing a highly efficient building envelope at the start of development, youll set yourself up for success.

Kenneth Carrell is the principal architect at ARE Associates in Lake Forest, Calif., an award-winning architectural firm specializing in the self-storage industry. For more information, call 949.305.4752; visit www.areassociates.com .