Allen & Major Associates, Inc." width="200" height="275" /> Benjamin Schlick, Allen & Major Associates, Inc.

Conventional retail stores have a simplistic structural framing scheme comprised of a steel shell with open bays allowing for a versatile floor plan; however, the retail industry is attempting to evolve its store concepts in order to provide a new type of shopping experience for its customers and keep up with competing Internet sales. While there will always be new construction, the renovation and expansion of existing retail stores is taking on a more dominate role in the structural engineering realm.  Commercial spaces are being re-designed, renovated and expanded to rebrand, modernize or accommodate long term lease tenants who want to occupy multiple floor spaces.  Specific movements we are seeing in structural design include open facades and expansive glass work, new means of egress for multiple floor tenants, and adaptive re-use of non-traditional buildings.

Open facades and expansive glass work

Opening the facade of blockish buildings provides a visual connection to the outside as well as providing natural light, which translates largely to an improved shopping experience.  Façade structures and glazing systems are designed to work together to produce visual appeal, improve the performance and sustainability of the building envelope and security. 

An example of this is the redesigned Ira Audi in Peabody, Mass.  This project involved demolishing 30% of the existing building and adding two new custom designed areas to both the front and back of the building.  The addition to the front of the building offers an increased show room layout and visual draw by providing an updated look to the signature Audi template. A free standing glass vestibule was designed at the main entry and coordinated with the open glass façade to provide a uniform look on the exterior while maintaining the function of a vestibule to separate the interior conditioned space from the exterior elements.  The addition at the rear of the building offers a service center for customers.  Similarly the Ira Toyota in Danvers produced a 25,000 s/f sales addition which utilized horizontal girts along the entire exterior of the building to maximize the glazing and provide structural attachment of the façade above and below the glazing line. 

Means of egresses for multiple floors

A specific challenge to renovating multi-story buildings that want to add a means of egress and egress path considerations within the floor plan layout is the retrofitting of the spaces to allow freight elevators and transport elevators within the existing structure of the building.  The structural engineer and architect must collaborate when placing a new stair/elevator within an existing structure to determine the appropriate locations that meet structural efficiency, construction costs and egress path considerations within the floor plan layout.  A further challenge is that the retrofitted floor may have to be self-supporting allowing that the egress stair/elevator to be removed if future tenants require the floor space.   This involves framing the opening so that the vertical load path goes back to the original columns and footings with retrofitting as required to meet code requirements.

Adaptive reuse of non-traditional buildings

Adaptive reuse is allowing retailers to gain access to desirable commerce areas. However, working with an existing structure is often the most challenging from a design standpoint.  It usually requires significant renovations and reconstruction, all while working within the limitations of the original structure.  Adaptive reuse projects require flexibility and innovative design because of their complexity.  Consider the project at 352 Newbury St. in Boston. The existing 2-story ice cream shop and office building was converted into a 4,500 s/f, two-story Scotch & Soda retail store. The brand, which is based in Amsterdam, was looking for an enhanced curb appeal, so the 1800s era building was retrofitted to accommodate a more open and modern entry.  Structural improvements involved removing a portion of the second floor at the main entry in order to create an airy and open, two-story entry with a balcony overlooking the first floor retail area.  Structural design and detailing of the interior atrium also included a staircase in the front of the building as well as an elevator from the basement up to the second floor.  Since most of Newbury St. was once part of Boston Harbor, unsuitable soils required the use of structural micropiles and grade beams in order to support the overall structure and allow for a full basement floor.

The retrofitting included supporting the increased code prescribed live loads for retail space, multiple egress openings, and a new staircase in the front and back of the store as well as the elevator.

The significance of these trends on retail structural design is that these various applications provide retailers with a remedy to the traditional vanilla box of the past.  While it may be stating the obvious, hiring an experienced structural engineer who is able to visualize your concept and execute your vision is the key to a successful project. 

Benjamin Schlick, P.E., LEED AP BD+C, is structural department head for Allen & Major Associates, Inc., Lakeville, Mass.