Exterior Alterations, Renovations and Rehabilitations to properties that are either a Landmark, a Protected Landmark or located inside a Historic District

Some projects are eligible for an Exemption and therefore are automatically approved, with no Certificate of Appropriateness (COA) needed.

Projects that do not qualify for an Exemption must be reviewed. There are two types of review.

Some types of projects are eligible for Administrative Review, which means that the City’s historic preservation planning staff can conduct the review without involving the Houston Archaeological and Historical Commission (HAHC). This includes projects that may be eligible for Mandatory Approval.

Some projects must be reviewed by the HAHC. Staff or the planning director can also refer projects for HAHC Review.

Staff members in the Historic Preservation office of the Planning and Development Department can help you determine which review process applies to your particular project, and they can assist you with your COA application, too. They can help you identify ways to streamline your application process, as well as ways to prevent pitfalls or delays. Involving staff as early as possible in your project planning process can save you time and money and help you achieve a successful outcome. Contact the office by phone at 832-393-6556 or by email at historicpreservation@houstontx.gov.


A Certificate of Appropriateness (COA) is not required for ordinary maintenance and repair, or for:

A COA is not required for the reconstruction of the portion of a contributing or noncontributing structure that was completely or partially destroyed by a fire, natural disaster, or other damage not intentionally caused by the owner of the structure, but only if the reconstruction is built within the same footprint and has the same exterior features as the contributing or noncontributing structure.

Note: Even though a project may not require a Certificate of Appropriateness, it might require a building permit. Contact the Houston Permitting Center in the Public Works and Engineering Department to find determine the regulations.

Administrative Review

Several types of alterations, which do not affect the historic character of the building, may be authorized administratively by the Planning and Development Director. This work includes the following:

If the Director disapproves the application, or if the Director does not approve the application within 15 business days of receipt of the complete application, the application shall be referred to the HAHC for consideration in the same regard as a Certificate of Appropriateness.

HAHC Review

All other work requires approval by the Houston Archaeological and Historic Commission (HAHC). In order for the HAHC to authorize a COA, they must find that the project satisfies each and every one of these eleven criteria.

Criterion #1: The proposed activity must retain and preserve the historical character of the property.

Historical character is the overall look and feel of a building. It is defined by a mix of factors, typically including architectural period and style, architectural integrity, how the building has changed over time, use and condition of materials, how the building is sited, and its overall setting. Changing one minor feature may not compromise the overall character, but the manipulation of significant elements will result in a loss of historic character. In order to authorize a COA, the HAHC must find that the proposed activity accurately and substantially preserves these features so that the overall historical character of the building, structure or object remains unchanged.

Examples of character-defining features that must be preserved include, but are not limited to:

Criterion #2: The proposed activity must contribute to the continued availability of the property for a contemporary use.

The way we live has evolved through the years. Historic preservation in Houston is not intended to restrict alterations to the point that a building is not permitted to evolve with the times. The goal, instead, is to maintain the historic character of a building, structure, site or object into the 21st century and to provide a historic context for today’s living. Sometimes this means finding a new use for an old building; for example, a warehouse that stored ice before the invention of electric refrigerators might find new life as a performing arts space, or a private home might be adapted into a professional office.

While Houston has many good examples of the adaptive use of historic structures, it is important to note that any deed restrictions or protective covenants placed on a property must be honored.

Criterion #3: The proposed activity must recognize the building, structure, object or site as a product of its own time and avoid alterations that seek to create an earlier or later appearance.

While Criteria #2 recognizes the evolution of how Houstonians use a space, Criteria #3 requires the HAHC to ensure that a project maintains the defining exterior characteristics of the period from which the structure obtains its significance. Adding elements from a different period may create a false historical impression. Gingerbread trim might be attractive, but does not necessarily belong on a Bungalow; similarly, a portico with Doric columns may make a grand statement for an entryway but would not be appropriate for a mid-century Ranch house.

Criterion #4: The proposed activity must preserve the distinguishing qualities or character of the building, structure, object or site and its environment.

A single distinguishing element can define the historic character of a building. A turret or cutaway bay window on a Queen Anne house, the four-over-one windows on an American Foursquare, or the front porch on a Bungalow are all distinguishing characteristics that could leave the structure historically unrecognizable if they were removed. Every effort should be made to retain and preserve character-defining features such as these.

For example, new windows, whether replacements or additions, should maintain the width and height proportion of the originals. Original porch structures should be maintained. The original roof pitch and shape should remain intact.

In order to approve a COA, the HAHC must find that the alteration, rehabilitation, restoration or addition preserves the distinguishing qualities that inform the character of the building, structure, object or site.

Criterion #5: The proposed activity must maintain or replicate distinctive stylistic exterior features or examples of skilled craftsmanship that characterize the building, structure, object or site.

One of a structure’s most significant character-defining elements is craftsmanship, and the tools and techniques used in one era produce a distinctive “look”that can be much different than that of other time periods. Construction details, such as the exterior woodwork miter joints on a Craftsman Bungalow, should be replicated, not replaced with an alternate joint connection, such as a butt joint. When craftsmanship is a significant contributor to the historic character of a structure, comparable care and skill must be maintained in the alteration, rehabilitation, restoration or addition of exterior features.

Criterion #6: New materials to be used for any exterior feature, excluding what is visible from public alleys, must be visually compatible with, but not necessarily the same as, the materials being replaced in form, design, texture, dimension and scale.

Building materials play a significant role in defining the historic character of a building. Alteration, rehabilitation, restoration or additions to any exterior feature visible from the public right-of-way must be harmonious with the structure’s original materials. Great care should be taken in assessing the effect of historic materials and the compatibility of new materials being introduced or combined to the existing.

It’s important to note that “harmonious” and “compatible” do not mean “exactly the same.” For instance, it may be acceptable to replace an irreparable piece of wooden siding with a cement fiber board of the same profile, texture, and dimensions as the original siding. It also may be acceptable to replace damaged historic wooden windows with composite windows, as long as the depth, sashes, muntins and profile are complementary to the original.

Criterion #7: The proposed replacement of exterior features, if any, should be based on accurate duplication of features as substantiated by available historical, physical or pictorial evidence (where that evidence is available), rather than on conjectural designs or the availability of different architectural elements from other structures.

When considering a COA for the purpose of replacing original features that may have been damaged or removed, the HAHC must find that the proposal maintains features significant to the structure’s historic character. Historical, physical or pictorial evidence may inform an appropriate replacement.

One great resource is the Houston History Association’s Guide to Researching Your Neighborhood’s History. It can be found here online, or go to HoustonHistoryAssociation.org. Additional sources from which to obtain evidence of historical features include:

Staff members in the Historic Preservation office of the Planning and Development Department are available to assist you locate such documentation. Contact the office by phone at 832-393-6556 or by email at historicpreservation@houstontx.gov.

Criterion #8: Proposed additions or alterations must be done in a manner that, if removed in the future, would leave unimpaired the essential form and integrity of the building, structure, object or site.

The HAHC will take into consideration the degree of impairment that an alteration or addition would cause to the original structure when considering the application for Certificate of Appropriateness.

Proposed additions or alterations range from mild to extreme, in terms of ability to impair the original historic structure. Mild changes may include installing new doors and windows in unaltered existing openings. Moderate changes may include adding new porches, balconies or penetrations to a front façade. Extreme examples may include the demolition of walls or a change in roof pitch or shape. The less damage that would be caused to the original, the more likely a Certificate of Appropriateness will be issued.

Criterion #9: The proposed design for any exterior alteration or addition must not destroy significant historical, architectural, archaeological or cultural material, including but not limited to siding, windows, doors and porch elements.

Alterations or additions may not destroy significant historical exterior elements. Removing and discarding historic exterior features, such as siding, windows, or doors is not allowable.

Criterion #10: The proposed alteration or addition must be compatible with the massing, size, scale, material and character of the property and the context area.

Alterations and additions to a property must be compatible with the existing neighborhood character and take cues from the property’s immediate context. The original structure should remain predominant, and alterations or additions should be subsidiary in scale to the original. An alteration or addition should not be taller than the typical height of structures within the context area, defined as the blockface and the opposing blockface within the district where the proposed activity is to be located. Additions that impact only the rear wall of the building and do not destroy the original historic fabric found in vertical walls and roof structures are preferable.

Second story additions should be set back as far as possible from the front facade of the house. In general, additions should be designed as a secondary structure, minimally impacting the historic structure, both physically and visually.

For example, in a neighborhood of post-World War II single-story Ranch homes, it is not appropriate to propose an addition of a second or third story; nor would it be appropriate to apply Tudor half-timbering to modern ranch façade. Similarly, it is not allowable to remove exposed roof rafters on a historic Craftsman home to avoid a similar application on a proposed addition.

Criterion #11: The distance from the property line to the front and side walls, porches and exterior features of any proposed addition or alteration must be compatible with the distance from the property line to similar elements of existing contributing structures in the context area.

On a typical blockface, the buildings are placed so that the common elements, whether it be a porch or front wall, are similar distance from the public right-of-way. This common siting creates a cohesive streetscape and establishes the street-to-façade proportions for the whole block. Proposed additions or alterations must in context with the prevailing distances of the parts of a building from the street. The Historic Preservation staff has significant data on the typical distances from the property lines and can help determine what is appropriate for any addition or new construction. Contact the office by phone at 832-393-6556 or by email at historicpreservation@houstontx.gov.

Think your project might be a Shall Approve? Click here to see if it meets the requirements.