The former Masonic Hall located on 9th and F Streets NW in Washington, D.C, built in 1869, was rehabilitated in 2001 for the Gallup Organization, and an addition was added.

It is inevitable that structures will age and outgrow their originally intended functions. With changes in technology and lifestyle, construction design is constantly updated to meet modern demands, leaving the predecessors in its wake. For those sensitive to history, it may be preferable to restore older structures to their former glory, however this is often not realistic. Adaptive reuse allows structures to retain their historical integrity while providing for the occupants' modern needs. Through changing certain elements of a building, an ecclesiastical structure can become a commercial structure, a commercial structure can become a residential building, and a residential building can even become an ecclesiastical structure. The possibilities are practically limitless.

A Case for Reuse

The question is often asked - why go through the trouble of retrofitting an older building rather than simply building a new one? In reality, there are many reasons for and against adaptive reuse. It is necessary to weigh the cultural distinction, aesthetics and expense for any project, so each structure must be analyzed on a case by case basis.

It is important to maintain architecturally and historically significant buildings. Not only do they provide an insight into the past, they put the present into perspective and context. Additionally, many lessons on modern design, aesthetics and construction can be taken from those learned in the past. Culturally significant buildings are a valuable resource, so when considering whether to reuse or rebuild, acknowledge the social responsibility to preserve the community's heritage. A building has an obligation to surrounding structures in keeping the atmosphere of a neighborhood or district, as the decision to demolish can permanently change it.

Older buildings often put a focus on aesthetics that modern buildings simply cannot afford. Built when skilled labor was cheap, buildings from the past have a high attention to detail. Architectural elements in these structures include sculpted stone, columns and capitals, elaborate masonry, vaulted ceilings and carved wood to name a few, all of which can be prohibitively expensive today. Adaptive reuse of such buildings allow for a building to retain much its character and aesthetic by incorporating these elements into the new framework.

Arguably the most important factor in the decision to reuse is cost. If a business entity is paying for the future space, it is concerned about profitability. Governmental agencies have budgets they must work within, and private interests are still restricted by their resources. As a result, unless the actual goal is restoration, it must be the more cost effective option to perform an adaptive reuse rather than rebuilding. There can be many cost advantages to reusing an older structure. To begin with, there are lower establishment costs. There is little to no demolition required, land acquisition is often less expensive, and many if not all of the required utilities and services are already connected and may only need modernization. There are additional savings in the fact that the structure is already in place. Material and their corresponding erection costs have already been accounted for.

Another financial benefit of adaptive reuse projects are historic tax credits. The Federal Historic Rehabilitation Tax Credit Program provides a 20% tax credit on applicable structures. Other local tax credits can apply from location to location. To be eligible for such a credit, a number of provisions must be met. The property must be certified historic by the National Park Service. In addition, it must be used for an income-producing purpose, finished in a timely manor, and the appropriate fees must be paid to NPS. Most importantly however, owners must follow strict guidelines for the rehabilitation, set forth by the Secretary of the Interior.

Guidelines for Rehabilitation

The former General Post Office Building in downtown Washington, D.C., built between 1839 and 1859, is now home to the Hotel Monaco after a 2002 rehabilitation.

Once the determination to perform an adaptive reuse has been made, the next step in the process is determining how. Specific to historic structures, the Secretary of the Interior has published Standards for Rehabilitation. These ten standards pertain to historic buildings of all types and apply to the interior, exterior and surrounding environment. The standards must be followed to apply for federal tax credits.

As outlined within the Standards, minimal change to a property's defining characteristics should be made. Its historic character shall be retained, preserving as much of the original fabric as possible. Additions that create a conjectured or false history are not to be made, although additions that have actually been made throughout a buildings life should be preserved. As much as possible, buildings elements should be repaired rather than replaced. If an element can not be repaired, then a replacement must be identical in appearance and material to the original.

Continuing within the Standards, buildings and their surrounds must not be harmed during the rehabilitation process. This includes the use of harsh surface treatments, damaging archaeological resources, or using irreversible connection methods for new additions. If a new work is to be made, such as an addition, it is to be differentiated from the old while still keeping with the original's architectural features and scale.

Practical Considerations

Not all structures require the level of aesthetic detail needed for historical rehabilitation. For many structures, practical considerations are the driving factor in adaptive reuse. Above all, the integrity of the building must be intact for the safety of the occupants and security of the interior.

Adaptive reuse projects will often change the structural makeup of a building in ways that are not obvious at first glance. New floor openings, increased load requirements and complete changes to the overall building structure are very common. These changes often require strengthening solutions which frequently evolve even as the project is taking place.

There are many different strengthening techniques that can be tailored to fit the aesthetic, logistic, and economic constraints of a particular project. Fiber reinforced polymers can be used to increase the capacity of a concrete member by up to 60% or more in a profile that is less than 1/4" thick. It is also possible to imbed the fiber reinforcing into the existing structure so that there is no noticeable change to the dimensions of the structure. Section enlargement and external post-tensioning are also very effective strengthening techniques when space limitations aren't as tight and the additional capacity requirements are high. Many times these techniques are used in combination to provide an overall strengthening solution that satisfies the many different parameters of a particular project.

Second to the structural integrity of a building comes its imperviousness. The weather makes a formidable opponent for building envelope components, so moisture and temperature ingress must be managed and understood. By definition, "envelope" is an encapsulating covering such as an outer shell or membrane. In simple building terms, it consists of the roof, the above grade wall system and the wall system below grade. For adaptive reuse, the key is to understand the original design intent and how its components are currently performing. Without proper attention to these details, the investment made for interior finishes is at risk.

Rehabilitation Process

Union Station in Washington, D.C. receives 25 million visitors a year. Rehabilitated in the 1980's, this building once slated for demolition has become a multi-use transportation hub, retail and entertainment center.

The success of any adaptive reuse project directly correlates to the quality and expertise of the team performing it. From the onset, the project should involve the owner, a design professional, a restoration contractor, and in the case of historical projects, a historical conservator and the local preservation office. Before looking to the building itself, every attempt should be made to determine its previous repair history, which can be found through maintenance logs, old reports or even through word of mouth. This will give an indication of how the building has performed, and what areas need attention paid to. After this initial step, in order to accurately determine how elements of the building should be adapted, a structure should receive a complete condition assessment by a design professional, with the aid of a qualified team. This will serve as a guide for the adaptive reuse project, and can help prevent unforeseen and often costly problems down the road. From here, the plan on how best to manipulate the existing footprint can be developed. This will vary greatly between projects, and will always be a compromise between the owner's needs and the limitations of the building. Finally, the actual work must be performed with high level of expertise and attention to detail. With adaptive reuse, errors and poor workmanship can permanently etch the face of a building - there is no second chance.

Adaptive reuse is increasingly seen as a viable option in comparison to demolition and rebuilding. As material prices and labor costs increase, the financial benefits in rehabilitation are becoming more apparent. In addition, more recognition is being given to the less quantifiable benefits. The look and feel is preserved for communities, and historical integrity is maintained for society. With adaptive reuse, we can harness the past and use it again for the future.

Authors

David Clark is a Project Engineer with Structural Preservation Systems. He regularly authors a column on historic preservation for the newsletter of the Washington DC Chapter of the Association for Preservation Technology (APT) International. 

Matt Frye is a Project Manager with Structural Preservation Systems in Baltimore, MD.