The Challenges of the Retail Building Market
Based on a significant number of successfully constructed retail projects, a unique understanding of the sustainability challenges surrounding such projects has been developed. The major challenges to successful projects can be split into two
categories; technical and industry.
Industry challenges largely relate to difficulties in the construction of the base building and the relationship with the tenant. Some of these difficulties include:
- Building owners are distanced from energy bills. Tenants pay for the utility bills, but building owners pay for the equipment that can reduce these
bills. With an incredibly competitive leasing field, building owners rarely see a return on their investment in energy efficiency.
- Designs are complete before the space is leased. Aside from most anchor tenants, projects are often completed design before they are fully leased. This creates a need for one size fits all mechanical sizing. Combined with inefficient equipment, this leads to a significant energy penalty once the
building is in operation.
- Two groups of design teams. Since both the base building and the tenant have their own set of designers and the communication between both is
limited, extra requests and misunderstandings are common. Often extra equipment is requested to meet prototype standards, with little consideration
of an improved shell, or equipment efficiencies. Conversely, without accurate interior loading information, the mechanical sizing is at best a guess.
Technical challenges relate to how and what systems are implemented by both the base building designer and the tenant designer. These difficulties include:
- Preferred HVAC equipment is inefficient. The preferred HVAC system for most retail projects is the single zone constant volume system. This system is preferred because it ensures that all heating, cooling and ventilation is provided without utilizing any leasable floor space. It is also a relatively inexpensive option from both a capital cost and design cost perspective. Since the units are so simple, they are easily setup and readily serviced by industry. From an operator standpoint, limited extra training is required as the controls are similar to a common residential system.
- Inexperienced designers. Because of the extreme competition and the low-cost nature of most retail developments the base building firms will frequently use their least experienced (and least expensive) designers to develop the base design. Since these designs are frequently based on a prototype or rules of thumb, the design ends up functional, though rarely energy efficient. However, changes to the basic templates can result in a new design that should be more efficient, but ends up being significantly worse, either through calculation error or incorrect equipment specification. Similarly for tenant designers, when a prototype is available, the designs are functional, if not spectacular. Completely new designs can see a lack of recognition of codes and standards and result in extremely poor energy use.
- Oversized Equipment. All other challenges combine to form a propensity for the industry to oversize equipment. It is common to install cooling equipment based on 200 square feet per ton, however with improved envelopes and proper identification of interior loads, 400 to 600 square feet per ton would be an achievable target for the building type.
Since oversizing equipment is one of the major issues resulting in increased energy use in retail buildings, one of the five scenarios presented addresses it exclusively. To limit its effect on retail designs, two methods can be used:
- Utilizing designs where operating performance is not significantly penalized by the oversizing. For example, introducing variable speed systems.
- Addressing the oversizing issue directly by providing all engineering sizing calculations used to determine peak cooling requirements for the building in a spreadsheet to be downloaded from the cn(sbs.cssbi.ca website, so that they may be reviewed by designers.
Regardless of the approach taken for addressing oversizing, the rest of the challenges present interesting constraints to work with. To develop a net zero design strategy that achieves credibility in the marketplace, these challenges must be taken into consideration, and to an extent worked around. The crux of success for the more aggressive strategies will be to stretch the traditional relationship boundaries between designers.