With fewer green fields available and property value increasing, retrofitting buildings has become a growing trend over the years. Citing McGraw Hill data, the U.S. Green Building Council found that 61 percent of all construction projects in recent years have been retrofits.
Real-estate investors are trying to find ways to make available existing space work for their needs while converting these older buildings into something more sustainable. Nearly 75 percent of leading investors plan to invest in net-zero initiatives in the next three years, meaning parts of these existing buildings must be improved. In addition, at the end of 2021, the average U.S. commercial building was more than 50 years old, resulting in many of these buildings requiring a retrofit because of aged and degraded façades and systems.
To retrofit a building enclosure, there are certain best practices that can be used to prepare for the process. The objective is to gather as much relevant information as possible. From a carbon and building-structure standpoint, the entire team needs to know what they are getting into before a project begins.
Consider the following eight best practices before beginning your next building enclosure retrofit:
1. Team Meetings
It is crucial to get all relevant stakeholders in the room together early. Depending on the project, the architect of record or the owners representative can be responsible for assembling and managing the team for the due diligence and operational execution of the project.
Engage with architects, façade consultants, the owner or an owner representative, along with any other key stakeholders. This will help build a consistent understanding of the retrofit’s objectives. Because most projects are not cookie-cutter builds, there may be sacrifices on the project, and everyone needs to be onboard with these changes.
For example, the team must ensure new products being attached to the existing envelope will function properly with the building as a whole. Because structural codes need to be met, it must be understood who owns the structural engineering of the building. There is usually an engineer of record, but this can be determined in this early collaboration process.
When it comes to preparing to retrofit a building enclosure, reconnaissance is key. For example, are there existing drawings of the structure? Will the team have access to these drawings? Or must the drawings be recreated based on what is seen?
If drawings need to be recreated, a data-point scan likely will be needed to create a model. A physicality survey of the building is also necessary to see what parts of the current building remain adequate for its future use.
3. Energy Codes
Through the reconnaissance phase, it should be determined how new energy codes need to be applied and whether they need to be applied to a new addition only or the entire building. Many times, code-related items are not black and white, and the code may not address a specific scenario. Communicating project goals and objectives in a collaborative effort with building code officials is a great way to ensure compliance and also get a variance to achieve specific project objectives.
For example, if a building owner wants to replace an elevation of windows on a 50-year-old building, if not properly coordinated, it could result in the entire building being required to meet current-day building codes. This could mean replacing all windows, adding insulation inside existing walls, increasing the R-value in the roof through additional insulation and membrane, or even replacing the roof.
4. Picking and Choosing
During the planning process, decisions must be made about what will stay and what will be removed from the structure. Determining this will help develop an expectation of the finished product. These expectations will clarify responsibility for certain aspects of the project. When the renovation is transitioning from brick to a curtainwall, for example, who will be responsible for the transition and pull test? Who has the warranty for the materials and work? These questions must be answered before the project begins. Part of this collaboration includes determining whether the existing structure has been evaluated for any issues. Has the steel rusted? Is it usable? Does it need to be supported? Who is responsible for that?
5. Compatibility between New and Old
Compatibility studies should be completed early and often in the project, including as the envelope materials and systems are selected and specified. This will help the team learn how all pieces will interact and if the materials will be compatible with the rest of the building.
Material compatibility is not limited to what’s on the surface. In many cases, existing brick has been painted, sealant joints have been re-sealed multiple times using different sealants and leaks have been fixed with unknown materials. In this scenario, the proper amount of time should be taken to understand what new materials will be interfacing with what existing materials, and appropriate tests should be performed to ensure compatibility and warranty.
Compatibility of systems also is important. A point-supported curtainwall system will interact with its structural support differently than the 1960s traditional masonry wall that the architect wants to remain within the façade, for example. Studying the compatibility of the differential movement of these components will ensure that the systems will perform independently, and together, as intended.
PHOTOS: courtesy IWR North America