Codes and Regulatory Requirements for Rehabilitating Historic Buildings

Rehabilitating historic buildings involves compliance with code and regulatory requirements, including accessibility, fire and life-safety, mitigation of hazardous materials, and seismic upgrades. In addition to meeting Federal and State codes, which vary from state to state, rehabilitation projects have to meet local codes, which vary from town to town. Consultation with code officials, State Historic Preservation Offices (SHPOs) and the National Park Service (NPS) in the early stages of the planning process can ensure that rehabilitation projects achieve appropriate solutions that satisfy applicable code requirements and meet the Secretary of the Interior’s Standards for Rehabilitation.

Because there are so many variables regarding code and regulatory issues it is not possible to address them all in depth. The purpose of this paper is to provide a broad overview of code and regulatory requirements as they impact historic buildings and to acknowledge the complexities of accommodating them in a manner that is sensitive to the historic building and that preserves its character. Two publications provide more specific guidance on accommodating these regulatory requirements in rehabilitation projects:

Accessibility and the Americans with Disabilities Act (ADA)

The NPS was instrumental in implementing the ADA and worked with numerous public and private partners to make these guidelines sympathetic to historic buildings. The historic preservation tax incentives program provides flexibility to incorporate upgrades for accessibility that are compatible with historic buildings and meet the Standards.

New accessible features such as ramps, lifts, elevators, and elevator towers should be added in the least intrusive locations. Adding these features to primary elevations and significant interior spaces is discouraged. If appropriate, components for accessibility may be placed on the interior of buildings where their costs can be included in the overall rehabilitation costs eligible for the credit.

Fire and Life-Safety

NPS is proactive in its approach to keeping historic buildings safe in the event of a fire, natural disasters, other threats or emergencies. It is responsive to new building codes through its involvement with the development and implementation of the International Building Code (IBC), which now includes sections on historic buildings.

Many jurisdictions have adopted IBC in lieu of several existing building codes used in different areas of the country. This is beneficial because IBC’s section on historic buildings is more compatible with the Standards. In the past, codes for new construction, existing buildings, and historic buildings were combined, leaving little room for flexibility. In response, IBC is more “performance-based” in its approach, as opposed to “prescriptive,” and evaluates each building on its individual merits. This allows greater cost savings and further protection of historic resources. Many states and localities are adopting individual rehabilitation sub-codes specific to historic buildings. Greater flexibility, cost savings and protection of historic resources are experienced in states with these codes.

NPS partnered with the National Fire Protection Association (NFPA) and helped develop the Building Construction and Safety Code – NFPA 500, specifically Chapter 15: Building Rehabilitation.

Impact-resistant windows are increasingly the focus of new life-safety regulations, specifically with regard to hurricane-strength winds and threats of terrorism attacks. NPS works with SHPOs, building owners, architects and manufacturers of windows and other related products to ensure that rehabilitation projects where impact-resistant windows are required will meet the Standards.

Hazardous Materials

Hazardous materials present in historic buildings generally require some level of mitigation. This mitigation must meet applicable environmental codes and it must not impact historic integrity. One of the most prevalent hazardous substances is lead-based paint. The U.S. Department of Housing and Urban Development, Office of Lead Hazard Control and Healthy Homes has changed its approach from “abatement” to “interim controls,” encouraging practices that are less costly than previous treatments and more sensitive to historic resources. “Interim controls” are treatments lasting at least six years and are generally tied to proper maintenance and good hygiene. The most common “interim control” is paint stabilization in areas of friction and high impact.

Seismic Retrofit

Depending on location, a rehabilitation of an historic building may require adding structural reinforcement to meet seismic codes. Assembling an experienced professional team and early identification of the seismic risk factors of a historic building are very important in implementing a successful seismic retrofit plan.

Prescriptive code requirements can often result in excessive removal of historic materials or significant alterations to the historic character of a building. However, with careful planning it is possible to introduce new structural reinforcement in a manner that minimizes alteration or removal of spaces, features, and finishes that give a building its unique historic character. Recognizing those features that are important in defining the historic character of a building is essential in order to determine what means and methods are best suited for a successful seismic retrofit plan.

As stated in Preservation Brief 41: The Seismic Retrofit of Historic Buildings: Keeping Preservation in the Forefront, the three important principles to be kept in mind when considering a seismic retrofit plan are:

  • Historic materials should be preserved and retained to the greatest extent possible and not replaced wholesale.
  • New seismic retrofit systems, whether hidden or exposed, should respect the character and integrity of the historic building and be visually compatible with its design.
  • Seismic work should be reversible to the greatest extent possible to allow removal for future use of improved systems and traditional repair of remaining historic materials.


Last updated: June 6, 2024