Committee on the Environment

Each retrofit project is a unique and complex undertaking with its own history, conditions, and performance challenges. Taking a holistic approach that accounts for not only the project's goals, but also how all building systems will work together over the long term, will ensure it meets and exceeds modern energy efficiency and fire performance standards, and offers durability for decades. And choosing the right materials, like stone wool insulation, is a critical part of this strategy.

Why retrofit?
The motivation for retrofitting a building can be as varied as the buildings where these retrofits are undertaken. The building may no longer be performing as intended, the indoor conditions may no longer be comfortable, or changes may be needed to keep up with modern energy code requirements.

Retrofits are also increasingly common to change a building's function, as with industrial buildings being modified for commercial purposes.

Retrofits may also be needed to address environmental concerns such as improving energy efficiency to reach sustainability targets or reduce operating costs related to energy consumption.

For building systems to meet their operational, financial, and sustainability goals, multi-disciplinary teams should look at retrofits as a holistic solution, rather than a series of discrete tasks.

A systems approach is needed
Successful retrofits don’t happen in isolation. Upgrading a single element without considering its impact on others can introduce new challenges, from condensation and enclosure durability to thermal bridging. This may lead to further unplanned and preventable repair costs in the future.

While retrofitting is never a one-size-fits-all project, the goal should always be durability regardless of whether the work is a targeted upgrade or a total transformation and repurposing. Approaching retrofits as a systemic undertaking that integrates the building envelope, fireproofing, mechanical systems, and long-lasting interior spaces creates a cohesive plan that saves money and will result in a valuable property for decades to come.

Many types of retrofits
Whether you’re preparing for a minor, major, or deep retrofit, the first step is to clearly define desired outcomes, which will directly inform the scope and scale of the project.

Minor retrofits
In many cases, a minor retrofit, such as improving energy performance and air quality through caulking or replacing seals and gaskets, may be all a building needs to achieve long-term goals. Or it might provide a temporary solution until funds are available for a more complex project.

Major retrofits
When caulking and new lighting won’t cut it, a major retrofit may be required. This requires the team to take a holistic view and will involve higher costs with some (though often minimal) occupant disruption. Major retrofits can have a significant and often immediate impact, leading to better energy efficiency and building performance, as well as increased occupant satisfaction.

Deep retrofits
When a building is changing its intended use or requires substantial upgrades to comply with modern building codes and sustainability programs, a deep retrofit may be needed. This involves significantly reconfiguring the interior while also enhancing the larger building enclosure.

While more extensive, costly, and disruptive than minor or major retrofits, deep retrofits can also result in more savings, advanced building performance, and an ability for building owners to attract premium tenants.

Choosing the right strategy
Since the scope of retrofits can vary drastically, each project starts with understanding the building’s constraints, goals, and opportunities.

Interior
In buildings where exterior work is restricted by factors such as historic preservation rules and ordinances, an interior retrofit is the best (or only) option. These projects need to be carefully scoped out to ensure airtightness is maintained, thermal bridging and transitions are managed, and disruption for building occupants is limited.

Project owners took this approach for the conversion of 369 Warren St. in Brooklyn from a former carriage house into a modern office space, which sought to achieve Passive House certifications with minimal alterations to the building’s historic exterior.

Exterior
Where owners and operators have more flexibility in altering a building’s exterior, or where energy goals and building repairs can’t be managed entirely through an interior retrofit, an exterior retrofit may be recommended instead. While more complex, exterior retrofits can improve overall building durability, keep structural elements better protected by reducing condensation risks, and present the opportunity to update the building facade.

A rainscreen over cladding system might be a good option when the project requires a complete facade overhaul. The East 97th Street project in New York City’s Upper East Side is a good example of this type of retrofit.

The project team behind the retrofit of Engine 16 in New York City, a former firehouse, opted instead for an EIFS design on a section of the exterior walls where preserving the original facade was not required.

Why stone wool?
Regardless of retrofit strategy, choosing the right materials plays a key role in enhancing building performance. Particularly in cooler climates, reduced drying potential can increase condensation risks. Selecting properly integrated air and water control layers is critical for preventing issues like convection loops, trapped moisture, and surface drainage failures.

Stone wool is one insulation option that supports multiple goals during a retrofit. Specifiers and builders often choose stone wool insulation because it is inherently noncombustible. It will not develop toxic smoke or promote flame spread, even when exposed to a fire. Stone wool also offers excellent thermal performance to maintain consistent indoor temperatures and improve energy efficiency. It’s hydrophobic and highly effective at absorbing sound to reduce noise transmission.

This durable and dimensionally stable insulation material is a versatile and sustainable option for a variety of applications, including retrofits. Where new building codes, improved energy efficiency, and enhanced fire performance are key considerations, stone wool insulation can help achieve all your retrofit goals.

Retrofits are inherently complex and need custom solutions that consider how every system in the building interacts over time. Stone wool’s versatility makes it a proven solution to meet diverse retrofit challenges, including modern energy efficiency and fire resistance standards. By selecting the right solutions and the right materials, including products like stone wool, these retrofits can meet today’s goals and targets, while building something that lasts into the future.

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