WINDOW CHECKLIST

For Design, Specification, and Installation

This checklist guides homeowners, architects, and builders in selecting residential windows and skylights. Blanks are provided for checking off entries during the selection or design process. Selecting the right window can be difficult because of the many factors involved and the great variations in climate, utility costs, and occupant needs. Note that each entry below does not apply to all circumstances and that some general guidance may appear to be contradictory because all of the detailed conditions cannot be specified. Users should mark the items that apply to their particular needs. Other local sources of information for window selection are utilities, state and local code officials, design professionals, and building materials suppliers.
 

• Insulation and Condensation Values
• Sun Light Control
• Window Shading
• Daylight Levels
• Ventilation and Air Tightness
• Sound Control
• Privacy, Security, and Safety
• Maintenance and Durability
• Installation
• Economy

Insulating Value and Condensation Resistance

Look for NFRC U factor ratings and labels to guide selection. Select double-pane windows in all but climates where no heating is needed. Select double- or triple-pane windows with low-e coatings and gas fills in cold climates to reduce heat losses and condensation. Select windows with wood, vinyl, fiberglass, or properly designed thermally broken aluminum frames in all climates where heating is needed, to reduce frame and edge heat losses and condensation. Use heavy drapes, thermal shades, or thermal shutters to provide additional window insulation in cold climates.

Solar Control and Ultraviolet Protection

Look for NFRC Solar Heat Gain Coefficient ratings and labels to guide selection. Select windows with spectrally selective glazings (special tints or modified low-e coatings) to reduce solar heat gains (SHGC < .4) while maintaining high visible transmittance (glass transmittance > .6. Select tinted windows to reduce solar heat gains and control glare by lowering visible transmittance. Select special glazings (with plastic layers or low-e coatings) to reduce ultraviolet transmission in rooms with materials subject to fading. (If this is a critical concern, consult expert assistance.)

Shading Devices as Supplement for High Performance Windows

Select light-colored shading devices to minimize solar heat gains. Select exterior shading devices to minimize the inward flow of absorbed solar heat. Select interior shading devices to reduce solar heat gains while providing for privacy and aesthetics, or when exterior shading devices cannot be used. Select horizontally oriented shading devices for south-facing windows and vertically oriented shading devices for east- and west-facing windows. Specify overhangs, exterior awnings, or the planting of deciduous trees and shrubs to shade south-facing windows during the summer while allowing beneficial solar heat gains during the winter.

Daylight and View

Select window size, location, and glass type to provide adequate daylight levels in each space. Select windows with high visible transmittances (> 50b) to maximize outward visibility. Specify window sizes and positions in walls to take advantage of desirable views. Position windows away from bright external surfaces that create glare.

Ventilation and Airtightness

Select operable windows for rooms requiring substantial ventilation during mild weather and to meet building code egress requirements. Select casement or awning windows to maximize effective ventilation area. Select awning windows to better exclude precipitation while ventilating. Position operable windows in opposite walls of living spaces to maximize cross-ventilation. Select fixed windows or windows with compression seals to minimize infiltration. Select windows and skylights with continuous edge seals to minimize infiltration. Seal and caulk around window and skylight frames and sash to reduce infiltration. Follow manufacturers' installation instructions.

Sound Control

Position windows away from external sources of extreme noise. Select double- or triple-pane windows with panes of unequal thickness, laminated glass, or gas fills to minimize noise from the exterior.

Privacy, Safety, and Security

Select interior shading devices that obscure direct view for additional privacy. Check building codes on fire, wind-loading, and seismic safety before selecting and positioning windows and skylights. Select laminated glass or tempered glass with screens for skylights and for windows near doors or close to the floor. Select windows with locks or latches that can be easily opened from the interior but cannot be opened from the exterior.

Maintenance, Durability, and Lifetime

Check warranties for indication of durability and lifetime before selecting windows and skylights. Check the quality of window construction. Use protective paints, stains, or sealants on wood window and skylight frames or select clad wood products. Follow manufacturers' instructions to maintain glazing, sash, frame, and hardware in good repair.

Installation

Check all applicable building codes before installing windows and skylights. Follow manufacturers' installation instructions carefully.

Economics

Consider the relative effects on utility bills when selecting windows and skylights. Contact the National Fenestration Rating Council (see Window Labeling) or consult energy specialists or utility representatives for estimates of the energy and cost savings provided by energy-efficient windows and skylights. Consider the effects on the resale value of a home when selecting windows and skylights. Check local, state, and federal energy efficiency programs and utility energy conservation programs for economic incentives for installing energy-efficient windows and skylights.

Note: This section is information published by The Department of Energy - it does not imply an endorsement to The Window Place.

Author: DOE Windows and Glazings Research Program Program contact: webster-btp@lbl.gov Last Update: Jan. 29, 1996.