A07: Operable Windows

(2 points)

INTENT

Increase the supply of high-quality outdoor air and promote a connection to the outdoor environment by encouraging building users to open windows when outdoor air quality is acceptable.

SUMMARY

This WELL feature requires buildings with operable windows to increase the supply of high-quality outdoor air and promote a connection to the outdoor environment by encouraging building users to open windows when outdoor air quality is acceptable.

ISSUE

Inhalation of harmful indoor substances is correlated with adverse health outcomes such as infectious diseases, cancer, asthma, allergies and other respiratory infections.

SOLUTIONS

Achieving natural ventilation through open windows can provide a positive human experience but is a challenge to the ability to maintain strict control over interior air quality. Despite often having conditions of temperature and ventilation below recommended standards, studies have shown that naturally ventilated buildings have fewer people reporting sick building syndrome symptoms than mechanically conditioned buildings. In addition, studies have shown that there is a 7.7% productivity benefit associated with naturally ventilated spaces. When weather and local outdoor parameters indicate high-quality outdoor air, people should be encouraged to make use of natural ventilation strategies. Therefore, it is necessary to provide information to building users when outdoor conditions are favorable for window opening. Educating building users is an important step, as human behavior is rated as one of the top three components that affect generation and persistence of indoor air pollutants.

IMPACT

When outdoor air quality is favorable, opening windows can provide a supply of outdoor air and lower levels of indoor air contaminants, which is supportive of healthy and environmentally conscious buildings.

REQUIREMENTS

Part 1

Provide Operable Windows (1 point)

Verified by Architect, MEP, Photographic evidence

For All Spaces

Note: Projects where the average outdoor PM_2.5 level is 35 μg/m³ or higher may only achieve Part 1: Provide Operable Windows in conjunction with Part 2: Manage Window Use. The World Health Organization’s Global Urban Ambient Air Pollution Database may be consulted to view outdoor air quality levels, available at http://www.who.int/phe/health_topics/outdoorair/databases/cities/en/

The following requirements are met: 

• Project meets one of the below:
  • At least 75% of regularly occupied spaces have operable windows that provide access to outdoor air.
  • The openable window area is equivalent to at least 4% of the net occupiable floor area of that space or floor plate.

• Project does not use radiant cooling systems if situated in climates with an annual relative humidity above 70%.

Part 2

Manage Window Use (1 point)

Verified by MEP

For All Spaces

Note: Projects may only receive points for this part if Part 1: Provide Operable Windows is also achieved.

Outdoor air measurement:

The following requirements are met:

1. Outdoor levels of ozone, PM_2.5 or PM₁₀, and temperature are monitored at intervals of at least once per hour based on a data-gathering station located within 4 km [2.5 mi] of the building.

2. Data collected are made available to building occupants.

Window operation:

Indicator lights at windows and/or online notifications signal to regular building occupants when outdoor air allows for open windows based on when the following thresholds are met:

1. PM_2.5 less than  15 μg/m³.
2. PM₁₀ less than  50 μg/m³.
3. Dry-bulb temperature within 8 °C [15 °F] of indoor air temperature setpoint.
4. Ozone less than 51 ppb.

Part 3

Apply Universal Design to Windows (1 point)

Verified by Architect

For All Spaces

All operable windows in regularly occupied spaces comply with the following requirements:

1. Provide enough space to permit occupants to approach and operate them (from both a standing and seated position).
2. Are operable with one hand and with a closed fist and do not require tight grasping, pinching or twisting of the wrist.
3. Require less than 22 N [5 lbs] of force to open.

© International WELL Building Institute