Window Replacement Solutions for Commercial and Institutional Buildings
Modernizing existing buildings with new manufactured windows to improve energy efficiency, lower maintenance, and enhance design.
This course is no longer active
Sponsored by Pella and EFCO
Rehabilitation Strategy: Replace
Recommended
- Replacing in kind an entire window that is too deteriorated to repair using the same sash and pane configuration and other design details
- If using the same kind of material is not technically or economically feasible, then a compatible substitute material may be considered
Not Recommended
- Removing a character-defining window that is unrepairable and blocking it in; or replacing it with a new window that does not convey the same visual appearance
Rehabilitation Strategy: Design for Missing Historic Features
Recommended
- Designing and installing new windows when the historic windows are completely missing
- Replacement windows may be:
- an accurate restoration
- a new design that is compatible with the window openings and the historic character of the building
Not Recommended
- Creating a false historical appearance because the replaced window is based on insufficient historical, pictorial, and physical documentation
- Introducing a new design that is incompatible with the historic character of the building
Rehabilitation Strategy: Building Additions or Alterations
Recommended
- Designing and installing additional windows on rear or other-non character-defining elevations if required by the new use
- New window openings may be cut into exposed party walls
- compatible with the overall design of the building
- don't duplicate the fenestration pattern and detailing of a character-defining elevation
- Providing a setback in the design of dropped ceilings to allow for the full height of the window openings
Not Recommended
- Installing new windows that are incompatible with the building's historic appearance
- Inserting new floors or furred-down ceilings which cut across the glazed areas of windows
Rehabilitation Strategy: Energy Retrofitting
Recommended
- Utilizing inherent energy conserving features
- Improving thermal efficiency
- Installing interior storm windows
- Installing exterior storm windows which do not damage or obscure the windows and frames
- Considering the use of lightly tinted glazing on non-character-defining elevations
Not Recommended
- Removing historic shading devices
- Replacing historic multi-paned sash with new thermal sash utilizing false muntins or no muntins
- Installing interior storm windows that damage the historic window
- Installing inappropriate exterior storm windows
- Replacing operable windows with fixed glass or inoperable sash
- Using tinted or reflective glazing on character-defining or other conspicuous elevations
Summary of Historic Tax Credit Programs
The chart below summarizes the criteria and applicability of either 10% or 20% tax credits available for certified historic building rehabilitation. For future updates to this information, please refer to the latest documents available from the National Park Service.
Originally published in Architectural Record
Originally published in January 2012