Window and Door Replacement Worksheet

Windows and doors are very often character-defining features of an historic building. Applicants are encouraged to repair rather than replace historic windows and doors. However, if the condition of the feature is determined to be deteriorated beyond repair, it is important that the replacement feature is compatible with the style and character of the building.

• A Landmark Alteration Certificate is required for the replacement of historic windows and doors on buildings located in a historic district and for individual landmarks. Information about windows and doors on landmarked buildings and in historic districts and the process for assessing their historic significance, can be found in Sections 3.7 and 3.8 of the General Design Guidelines for Boulder’s Historic Districts and Individual Landmarks.
• Review by the Landmarks Design Review Committee (LDRC) is required for window and door replacement and the project may be referred to the full Landmarks Board for review if the LDRC considers the replacement is inconsistent with the guidelines and may be to the detriment of the property and/or the historic district.

The appropriateness of window and/or door replacement will be determined based upon characterization by staff and the Landmarks Design Review Committee using the following criteria:

Location: The location of the feature that is proposed to be altered is an important consideration when determining whether or not replacement or retrofit is appropriate.

• Primary Elevation: The façade, (primary elevation) of the house is usually the most prominent and important elevation and will contain character defining doors and/or windows. The front or principal elevation(s) of a building face a public right of way or other important public space such as a park.
• Secondary Elevation: The sides of the house (secondary elevations), while usually less visible, still may contain features important to the character of the building. Typically, a side of a building has less public visibility, and may have fewer character defining features than on the façade. An elevation that has visibility from an alley may be considered a secondary elevation.
• Tertiary Elevation: The tertiary elevation typically has little or no visibility from the public right of way and is usually located at the rear of the building. The rear elevation can often be altered without compromising the historic character of the house.

Historic Significance:

• Very Historically Important Window or Door: A window or door that has retained substantial integrity from the period of significance and is characterized by at least one of the following:

1. Defines the architectural type or style of the building and without it the architectural significance would be eroded.
2. Is constructed of a rare or unusual material that would be difficult or costly to replicate (i.e. stained or leaded glass).
3. Was executed with a high degree of craftsmanship that would render its restoration difficult or costly.
4. Conveys artistic merit through skillful integration of design, material, and color which is of excellent visual quality.
5. Demonstrates superior craftsmanship or is an example of the uncommon through elements of architectural design, details, or craftsmanship that are representative of a significant innovation.

• Historically Important Window or Door: The feature has retained integrity from the period of significance and is an integral part of the historic design or is essential to the understanding of the architectural type or style.
• Non-Historic Window or Door: Windows or doors that have been replaced or are so extensively altered that they are inconsistent with the pattern, proportion or materiality of the historic window or door. Non-Historic windows and doors may be retrofitted or replaced. However, the character of the retrofit or replacement should be compatible with the historic character of the building.

The condition of the window or doors must be evaluated once staff and the Landmarks Design Review Committee have determined that retrofit or replacement is appropriate.

A four level classification system is used to document the existing condition of each of the windows or doors. This classification is based on the system identified in the National Park Service publication, Preservation Brief #9, “The Repair of Historic Wooden Windows”. The appropriateness of window and/or door replacement will be determined based upon characterization by staff using the following condition classification criteria:

• Class I: “Routine Maintenance”, associated with small repairs, which are usually performed as part of a building’s annual maintenance program. This may include paint removal, re-glazing, weather-stripping, caulking, and repainting.
• Class II: “Stabilization”, shows a small degree of physical deterioration but can be repaired in place by patching, waterproofing, consolidating, or re-gluing existing material.
• Class III: “Partial Replacement” describes localized deterioration in specific areas that can be removed and replaced without requiring a full feature replacement.
• Class IV: “Total Replacement” is for windows that have been damaged beyond repair. This includes a completely rotted sill, warping or a combination of Class III repairs.

Common Window Types:

Fixed: Non operable; may have divided panes of glass. Sliding Double or Single-Hung: One of the most common window types; two sashes that move up and down. The panes may be divided into multiple panes or lights. For example, if the window has three panes in the upper sash and one pane in the lower sash it is called a three-over-one double-hung window. Casement: Hinged vertically to swing in and out Awning: Similar to a casement window, but hinged at the top. Hopper: Similar to a casement and awning window, but hinged at the bottom. Center Pivot: Hinged in the center to pivot open Jalousie: Multiple louvers set in a frame

The moving units of a window are known as sash and move within the fixed frame. The sash may consist of one large pane of glass or may be subdivided into smaller panes by thin members called muntins or glazing bars. Sometimes in nineteenth-century houses windows were arranged side-by-side and divided by heavy vertical wood members called mullions.