Choosing windows for your new home

Use this handy list from the Energy Efficiency and Renewable Energy Clearinghouse as a guide to choosing windows

Choosing the right windows for a new home can be difficult because of the many factors involved and the great variations in climate, utility costs, and occupant needs.

The following checklist was prepared as a guide for homeowners, architects, and builders in selecting residential windows and skylights.

The three major types of energy flow that occur through windows: (1) nonsolar heat losses and gains in the form of conduction, con - vection, and radiation; (2) solar heat gains in the form of radiation; and (3) airflow, both intentional (ventilation) and unintentional (infiltration).

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.

Insulating Value and Condensation Resistance

1. Look for National Fenestration Rating Council (NFRC) U-factor ratings and labels to guide window selection.
   
2. Select double-pane windows in all climates where 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.
   
3. To reduce frame and edge heat losses and condensation in all climates where heating is needed, select windows with wood, vinyl, fiberglass, or properly designed, thermally broken aluminum frames.
   
4. Use heavy drapes, thermal shades, or thermal shutters to provide additional window insulation in cold climates.

Solar Control and Ultraviolet Protection

1. Look for NFRC Solar Heat Gain Coefficient ratings and labels to guide window selection.
   
2. Select windows with spectrally selective glazings (special tints or modified low-E coatings) to reduce solar heat gains (SHGC less than 0.4) while maintaining high visible transmittance (glass transmittance greater than 0.6).
   
3. Select tinted windows to reduce solar heat gains and control glare by lowering visible transmittance.
   
4. 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.)

If shading devices are to be used to supplement the use of high-performance windows, consider the following points:

1. Select light-colored shading devices to minimize solar heat gains.
   
2. Select exterior shading devices to minimize the inward flow of absorbed solar heat.
   
3. Select interior shading devices to reduce solar heat gains while providing for privacy and aesthetics, or when exterior shading devices cannot be used.
   
4. Select horizontally oriented shading devices for south-facing windows and vertically oriented shading devices for east- and west-facing windows.
   
5. 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

1. Look for NFRC Visible Light Transmittance ratings and labels to guide window selection.
   
2. Select window size, location, and glass type to provide adequate daylight levels in each space.
   
3. Select windows with high visible transmittances (greater than 50%) to maximize outward visibility.
   
4. Specify window sizes and positions in walls to take advantage of desirable views.
   
5. Position windows away from bright external surfaces that create glare.

Ventilation and Airtightness

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

Sound Control

1. Position windows away from external sources of extreme noise.
   
2. 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

1. Select interior shading devices that obscure direct view for additional privacy.
   
2. Check building codes on fire, wind-loading, and seismic safety before selecting and positioning windows and skylights.
   
3. Select laminated glass or tempered glass with screens for skylights and for windows near doors or close to the floor.
   
4. 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

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

Installation

1. Check all applicable building codes before installing windows and skylights.
   
2. Follow the manufacturer’s installation instructions carefully.

Economics

1. Consider the relative effects on utility bills when selecting windows and skylights.
   
2. Consider the effects on the resale value of a home when selecting windows and skylights.
   
3. Check local, state, and federal energy efficiency programs and utility energy conservation programs for economic incentives for installing energy-efficient windows and skylights.

This checklist was produced by the U.S. Department of Energy's Office of Energy Efficiency and Renewable Energy by the Lawrence Berkeley National Laboratory, a DOE national laboratory.