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Adaptive Solutions: Retrofitting Buildings with Sustainable Systems

According to a 2023 report published by the Rocky Mountain Institute (RMI) titled “Transforming Existing Buildings from Climate Liabilities to Climate Assets,” the United States has more than 97 billion square feet of commercial buildings and 244 billion square feet of residential buildings, and 80% of them will still be in service by 2050. In fact, many of them will still be here in 100 years.

Retrofitting represents one of the best opportunities to improve the environment in our cities and involves modifications to existing commercial buildings that may improve energy efficiency or decrease energy demand. There is not one solution to all retrofits, but not every retrofit is so unique that design teams must start from scratch. As this article shows, many of the techniques and systems used to retrofit a building can be applied to future projects.

Buckhead High-Rise Restored with Panelization

Built in 1963, this 12-story brick Atlanta landmark was the one-time headquarters of Aaron’s Rents and is the oldest high-rise building in Buckhead, an upscale neighborhood just north of downtown.  And it was in dire need of a makeover. The owners wanted to preserve the aesthetic of the brick building but within a cost-constrained budget and swift timeframe. Three concepts were proposed by the design architect, Lyman Davidson Dooley Inc., and the design chosen called for a brick office building with large industrial-style windows. In turn, Balfour Beatty, the general contractor on the project, introduced the idea of using Sto Panel Technology® as an option that would enable the team to deliver the design intent in a short period of time and within budget, while actually increasing the square footage of the building.

309 East Paces prior to the retrofit.
309 East Paces prior to the retrofit.

StoPanel® Classic NExT ci was chosen for the cladding. This lightweight prefabricated panel is both energy efficient and durable, incorporating continuous insulation and StoGuard® an air and water-resistive barrier as standard components. StoPanel Classic NExT ci is unique in that each panel allows for drainage via weeps in its patented Sto Wedge Design.  

To achieve the appealing look of brick and granite, but without the high cost, weight, and intense labor, they chose StoSignatureÒ Brick and StoCreativÒ Granite. StoSignature Brick is a cost-effective, easy-to-apply decorative wall finish system that can be used over any Sto cladding or other prepared exterior surface to achieve the classic look of brick. The other finish, StoCreativ Granite, is an acrylic-based interior and exterior wall finish formulated for durability and low maintenance. It is easily trowel-applied and designed to provide the look of cut or polished granite but in a versatile, lightweight finish coating. The panels were produced and installed by StoPanel affiliate Southern Wall Systems at its manufacturing facility in a suburb of Atlanta, and then driven by truck to the jobsite at 309 East Paces.

Prefabrication was the perfect way to go, providing close to $500,000 in savings, as well as enhancing the energy efficiency of the building and providing a much faster and safer method of reconstructing the envelope on the busy streets of Buckhead.

309 East Paces following the retrofit
309 East Paces following the retrofit

The off-site manufacturing of the panels ran simultaneously with the demolition of the exterior of the building to reveal the structural core and shell. The panels were installed in just 22 working days, and the resulting time savings on the job were massive. There were also no weather delays, as the panels were constructed in a climate-controlled facility.  Installation was not just faster; it was also safer because the use of StoPanels minimized the work typically required for field-built construction, and the panels could be “flown” into place with a tower crane so there was minimal work required at height.

In addition to saving time and money, using Sto Panel Technology on the adaptive re-use project actually increased the interior space by 2,000 square feet. The building’s original skin was constructed of concrete masonry unit (CMU) and brick. The CMU sat on the slab infilling from the top of slab to the bottom of the beam. After the restoration, the new skin sits outside and bypasses the edge of the slab, which added eight inches around the entire perimeter of the building.

The team chose to maximize the use of existing materials and infrastructure, and not only is it now a tighter, drier building, it also has efficient HVAC systems, LED lighting, and a site infiltration trench to improve the quality of water run-off.

Rainscreen System Transforms Museum Facade into Work of Art

A renowned Minnesota businessman and philanthropist, Gerald Cafesjian, established the Cafesjian Art Trust in greater Minneapolis to share his collection of modern art with the public. Cafesjian had a particular passion for the medium of glass, inspiring him to assemble an extensive collection of contemporary glass sculptures.  

When the trust prepared to move to a different building, they realized they were inheriting a structure not meant for the display of art. Built in 1977, the space included a warehouse and offices and came with a dated look. This meant that the building’s facade needed a substantial upgrade to better reflect the museum’s mission and its artwork. Mohagen Hansen Architecture | Interiors had a vision for a brilliant, colorful building exterior, brought to life with varying shades of blue using StoVentec® Glass panels.

The StoVentec Glass Rainscreen system is an open-joint drained and back-ventilated wall system. It incorporates StoVentro sub-construction[SJ1] , producing a fully compatible and tested solution for an advanced high-performance wall assembly.

StoVentec Glass panels in three shades of blue from the StoVentec Glass color collection – 5002 (Ultramarine Blue), 5013 (Cobalt Blue), and 5017 (Traffic Blue) – allowed  the architects to deliver a customized, visually compelling building facade that could be installed over the previous exterior walls. StoVentec Glass panels are manufactured by fusing colors directly into the glass before the toughening process to create a permanent color that will not wear, scratch, fade, or incur water damage.

On the first visit to the site, the design team realized that the entrance to the building needed to be more prominent and recognizable. One goal of the design was to add an entry sequence and vestibule to clearly define the main entrance using I-beams.

The project team worked closely with Sto to craft custom shapes around I-beams that come through the walls. The use of StoVentec Glass allowed the glass to seamlessly connect to the adjacent material and clamshell around the beams. 

As a retrofit project, the StoVentro sub-construction attached to the existing substrate with bracket connections, enabling the 1,700 square feet of StoVentec Glass panels to connect to a flat plate.

StoVentro sub-construction is an adjustable, thermally efficient structural system of brackets, rails, fasteners, and accessories for rainscreen wall cladding assemblies. The sub-construction absorbs wind loads and dead loads present on the facade and incorporates corrosion resistance.

The solutions from Sto enabled the team to keep the exterior envelope intact to avoid energy and water intrusion concerns. The flexibility of the system allowed the freedom to choose sizes and colors to create their vision with a unique pattern.

The River Bend Food Bank and FISH of Galesburg after the retrofit.
The River Bend Food Bank and FISH of Galesburg after the retrofit.

EIFS and Resin Cast Shapes Create Aesthetic and Energy Retrofit

A third system option, using EIFS and StoCast Wood, was the star on a retrofit at the River Bend Food Bank and FISH of Galesburg, an organization committed to solving hunger in their local neighborhoods. For the organizations’ newest, 15,000-square-foot joint branch in Galesburg, IL, the two charities identified an old block building that would undergo a retrofit and serve as a new food pantry for locals in need. Utilizing an older structure’s skeleton meant reducing significant carbon emissions typically generated by the construction of a new building. However, it also meant dealing with declining structural elements that would need significant upgrades with regard to thermal performance and overall aesthetics.

The architectural firm on the project, Klingner & Associates, P.C., selected Sto for the building’s exterior materials. The first priority was taking the previously uninsulated block building and turning it into a high-performing, sustainable structure. The north and east facades featured brick walls with masonry backup, while the south and west walls were all cement masonry units (CMU).

Klingner & Associates first had the cracked masonry repointed and conducted an overhaul repair of the original walls. This would ensure the substrate was in suitable condition and needed to be completed before applying insulation and installing cladding materials.

The walls on the west side of the structure stand nearly 15 feet tall, so they wanted insulation on such large-scale walls to provide thermal benefits. To meet this requirement, the product of choice was StoTherm® ci, an EIFS that combines critical wall components into a single system. These components include StoGuard® air and water-resistive barrier, continuous EPS insulation, and a drainage cavity to keep the building dry. Combined, they lend long-term function to a structure with the energy-saving attributes that today’s most stringent building codes command.

The StoTherm ci is finished with 12,000 square feet of Sto’s Essence, an acrylic finish with dirt pickup resistance in a Medium Sand texture in two colors, Jersey Cream and Superior Bronze.

The architects designed the building for a different type of cladding for the two main entrances on its northeast corner. Originally searching for a cement board product, architects instead decided on StoCast Wood, which enabled them to deliver this time-honored and desirable aesthetic and something that was available from the same manufacturer.

Using StoCast Wood, they could equip the walls with StoTherm ci and have a simple material transition from EIFS to wood, allowing them to deliver a consistent protective wall system behind the entire facade while getting more than one aesthetic finish.

StoCast Wood facades feature lightweight, flexible, resin-cast wood grain planks that create an authentic wood appearance and can be stained with a wide range of StoColor® Wood Stains in glossy or matte finishes or coated with any of Sto’s high performance architectural coatings. For this project, architects specified 3,000 square feet of StoCast Wood in an Ironwood stain. Compared to natural or engineered wood, StoCast Wood serves as a durable and low-maintenance option, imparting longevity and reliability.

Sto’s exterior wall systems are equipped with the same control layers behind the cladding materials, all of which are designed to keep buildings dry and thermally efficient. Therefore, architects can design high-performing structures with contemporary visual appeal even when numerous cladding materials are required, which is now becoming a mandate in cities across the country.

By investing in retrofits that make your building more energy efficient, you can lower energy costs, reduce maintenance requirements, increase the value and productivity of your building, and reduce your environmental footprint.

Author: Karine Galla
Categories: Article, Sponsored, Retrofit