WELL Addenda

WELL ADDENDA

Review the complete list of addenda changes made to the WELL Building Standard.

Feature 68: Physical activity spaces

Type Description
Amendment
Type: Amendment
Post Date: 27 Apr, 2017

Remove: "a. Parks with playgrounds, workout stations, trails or an accessible body of water". Add: "a. A green space or park with playground features"


Amendment
Type: Amendment
Post Date: 27 Apr, 2017

Remove: "b. Complimentary access to gyms, playing fields or swimming pools". Add: "A workout station or fitness zone"


Amendment
Type: Amendment
Post Date: 27 Apr, 2017

Add: "c. A trail network."


Amendment
Type: Amendment
Post Date: 27 Apr, 2017

Add: "d. An accessible body of water or public swimming pool."


Amendment
Type: Amendment
Post Date: 27 Apr, 2017

Add: "e. A gym, fitness, or training center."


Amendment
Type: Amendment
Post Date: 27 Apr, 2017

Add: "f. A recreational field."


Amendment
Type: Amendment
Post Date: 27 Apr, 2017

Add: "access to" after "through complimentary"


Intent
Type: Intent
Post Date: 24 Oct, 2016

In the Feature description, remove the second paragraph. Replace with the following text:
'To promote physical activity through complementary on-site indoor and local outdoor physical activity spaces.'


Verification type
Type: Verification type
Post Date: 10 Feb, 2016

Add annotated map as required documentation, remove Architect Letter of Assurance.


Feature 69: Active transportation support

Type Description
Amendment
Type: Amendment
Post Date: 07 Jun, 2018

In part description, remove: "building's main entrance". Add: "main building entrance"


Alternative Adherence Path
Type: Alternative Adherence Path
Post Date: 26 Jul, 2017

Projects may include bike share docking stations toward the bike storage requirements of this feature. The docks must meet the same proximity requirements listed in the feature. The project must provide a minimum of 1 storage space for privately owned bicycles, with at least 1 additional storage space for every 6 bike share docks.


Intent
Type: Intent
Post Date: 24 Oct, 2016

In the Feature description, remove the second paragraph. Replace with the following text:
'Intent: To promote daily physical activity through the provision of on-site support for active commuting.'


Verification type
Type: Verification type
Post Date: 10 Feb, 2016

Add Owner Letter of Assurance as required documentation, remove Architect Letter of Assurance.


Feature 70: Fitness equipment

Type Description
Amendment
Type: Amendment
Post Date: 31 Jul, 2019

Some combination of the following is provided in the fitness space free of charge and accompanied by instructions for safe, age-appropriate use:
a. Pull-up bar.
b. Suspension training equipment.
c. Resistance bands.
d. Free weights.
e. Kettle balls.
f. Inflatable exercise balls.

The following requirement is met:
a. Projects provide some combination of age-appropriate cardiorespiratory and muscle-strengthening equipment (e.g., resistance band, pull-up bar) or amenities (e.g., recreational field or court) free of charge and accompanied by instructions for safe use.


Amendment
Type: Amendment
Post Date: 01 May, 2019

The following requirement is met:
a. Projects provide some combination of cardiorespiratory exercise equipment in an interior fitness space free of charge, in a quantity that would allow use by at least 1% of regular building occupants and accompanied by instructions for safe use.

Some combination of the following is provided in the interior fitness space free of charge, in a quantity that would allow use by at least 1% of regular building occupants and accompanied by instructions for safe use:
a. Treadmills.
b. Elliptical machines.
c. Rowing machines.
d. Stationary exercise bicycles.


Amendment
Type: Amendment
Post Date: 01 May, 2019

Add existing citation 27 for new requirement a.


Amendment
Type: Amendment
Post Date: 01 May, 2019

The following requirement is met:
a. Projects provide some combination of muscle-strengthening exercise equipment in an interior fitness space free of charge, in a quantity that would allow use by at least 1% of regular building occupants and accompanied by instructions for safe use.

Some combination of the following is provided in the interior fitness space free of charge, in a quantity that would allow use by at least 1% of regular building occupants and accompanied by instructions for safe use:
a. Multi-station equipment.
b. Bench-press with a self-spotting rack.
c. Full squat-rack.
d. Pull-up bar.


Amendment
Type: Amendment
Post Date: 01 May, 2019

Add existing requirement 27 for new requirement a.


Amendment
Type: Amendment
Post Date: 20 Oct, 2017

In 27 Apr, 2017 AAP, remove: "50 m (164 ft.)". Add: "200 m [650 ft]"


Alternative Adherence Path
Type: Alternative Adherence Path
Post Date: 27 Apr, 2017

For Feature 70, project teams may utilize a shared gym or similar physical activity space located within 200 m [650 ft] of the WELL project boundary. These spaces must be available for complimentary use by occupants. The project is required to submit documentation demonstrating that the space has adequate capacity for the project population, in addition to any other population that this shared amenity supports. Note: This ruling is specifically for Feature 68 and Feature 70. Compliance with other related features such as Feature 65 and Feature 66 is not implied.


Amendment
Type: Amendment
Post Date: 27 Apr, 2017

Add: "complimentary access to" after "exercise by providing"


Intent
Type: Intent
Post Date: 24 Oct, 2016

In the Feature description, remove the second paragraph. Replace with the following text:
'Intent: To promote both cardiovascular and muscle-strengthening exercise by providing on-site fitness equipment.'


Verification type
Type: Verification type
Post Date: 10 Feb, 2016

Add Owner Letters of Assurance as required documentation, add on-site spot checks as required verification, remove visual inspections.


Feature 71: Active furnishings

Type Description
Amendment
Type: Amendment
Post Date: 27 Apr, 2017

Add: "c. Pairs of fixed-height desks of standing and seated heights (which need not be located adjacent to each other)."


Intent
Type: Intent
Post Date: 24 Oct, 2016

In the Feature description, remove the second paragraph. Replace with the following text:
'Intent: To reduce sedentary behavior by making active workstations readily available to occupants.'


Verification type
Type: Verification type
Post Date: 10 Feb, 2016

Add Owner Letters of Assurance as required documentation, add on-site spot checks as required verification, remove visual inspections.


Feature 72: Accessible design

Type Description
Equivalency
Type: Equivalency
Post Date: 27 Oct, 2021

The Flemish S0C3 Integrale Toegankelijkheid has been deemed acceptable for the requirements of Part 1 for Belgium.


Equivalency
Type: Equivalency
Post Date: 04 Apr, 2021

The Swiss standard SIA 500:2009 has been deemed acceptable for the requirements of Part 1 for Switzerland.


Equivalency
Type: Equivalency
Post Date: 03 Jul, 2019

The Italian Code for Accessibility DM 236, 14 June 1989 has been accepted as an equivalent for ISO 21542:2011 of Feature 72 Part 1.

Projects seeking to use this equivalency must meet the following requirements:
-Where present, water fountains must meet ISO guidelines.
-Ramps with a rise over 500 mm should have a slope below 5%.
-Signage must comply with ISO guidelines for universal signage. Visual, audible and tactile signage using familiar symbols should be present in the project.


Equivalency
Type: Equivalency
Post Date: 26 Apr, 2019

Decreto del Presidente della Provincia di Bolzano 9 Novembre 2009, n. 54 has been accepted as an alternative for the requirements of Feature 72 Part 1 for South Tyrol, Italy.

Note that the Decreto del Presidente della Provincia di Bolzano 9 novembre 2009, n. 54 standard does not contain requirements for drinking fountains; as a result, projects with drinking fountains must comply with the associated requirements in ADA Standards for Accessible Design requirements.


Equivalency
Type: Equivalency
Post Date: 26 Apr, 2019

South Africa's National Building Regulations, Part S: Facilities for persons with disability (SANS 10400-S:2011 Edition 3) has been accepted as an equivalent for ADA Regulations of Feature 72 Part 1.


Equivalency
Type: Equivalency
Post Date: 29 May, 2018

Buildings without Barriers has been accepted as an alternative for the requirements of Feature 72 Part 1 in Europe.


Equivalency
Type: Equivalency
Post Date: 29 May, 2018

Fukushino Machizukuri Johrei has been accepted as an alternative for the requirements of Feature 72 Part 1 for Japan.


Equivalency
Type: Equivalency
Post Date: 26 Apr, 2018

The German standard Technical Rules for Workplaces: barrier-free design for workplaces ASR V3a.2 has been accepted as an alternative for the requirements of Feature 72 Accessible Design, Part 1a - Accessibility and Usability for Germany. Note that the ASR V3a.2 standard does not contain requirements for restrooms and/or drinking fountains; as a result, projects with these components must comply with the associated ADA Standards for Accessible Design requirements.


Equivalency
Type: Equivalency
Post Date: 22 Mar, 2018

Code on Accessibility in the Built Environment has been accepted as an alternative for the requirements of Feature 72. Note this is only applicable to projects in Singapore.


Equivalency
Type: Equivalency
Post Date: 05 Feb, 2018

The Decree of the Ministry for Regional Development of the Czech Republic No. 398/2009 Coll. on General Technical Requirements for Barrier-Free Usage of Construction has been accepted as an equivalent for ADA Standards for Accessible Design of Feature 72 Part 1.


Equivalency
Type: Equivalency
Post Date: 05 Feb, 2018

The UK Building Regulation Part M for access to and use of buildings has been accepted as an equivalent for ADA Standards for Accessible Design of Feature 72 Part 1.


Equivalency
Type: Equivalency
Post Date: 25 Oct, 2017

Boverket’s mandatory provisions and general recommendations (BBR), has been accepted as an equivalent for ADA Standards for Accessible Design of Feature 72 Part 1.


Equivalency
Type: Equivalency
Post Date: 20 Oct, 2017

The Indian codes for accessible design ISO 21542:2011 - Building Construction - Accessibility and Usability of the Built Environment, Appendix B "Anthropometrics and requirements for accessibility in built environment for elders and persons with disabilities" of Part 3, National Building Code of India, 2016, Vol. 1 and "Harmonised Guidelines and Space Standards for Barrier-Free Built Environment for persons with Disability and Elderly Persons, 2016 - Ministry of Urban Development, Government of India" have been accepted as alternatives for the American Disabilities Act (ADA) design regulations. Either code may be used by projects located in India.


Equivalency
Type: Equivalency
Post Date: 20 Oct, 2017

Irish Building Regulations TGD Part M has been accepted as an alternative for the requirements of Feature 72 Part 1.


Equivalency
Type: Equivalency
Post Date: 07 Sep, 2017

The Canadian Standards Association’s (CSA) “Accessible Design for the Built Environment” (CSA B651-12) has been accepted as an alternative for the requirements of Feature 72 Part 1 and 2. This equivalency may be used in Canada.


Equivalency
Type: Equivalency
Post Date: 31 Aug, 2017

The Taiwanese code for accessible design "Design Specifications of Accessible and Usable Buildings and Facilities" is an acceptable alternatives to the American Disabilities Act.


Equivalency
Type: Equivalency
Post Date: 26 Jul, 2017

The German DIN 18040:2010 Construction of accessible buildings - design principles is acceptable for Feature 72 Part 1a. Note, similarly to the application of the Americans with Disabiliites Act (ADA) Standards for Accessible Design to buildings in the US, the German code must apply to all types of buildings. Furthermore, all WELL buildings should be considered "accessible" buildings for the purposes of the code.


Equivalency
Type: Equivalency
Post Date: 27 Apr, 2017

Previously published as an AAP:
Projects may apply the Government of Hong Kong Special Administrative region Building Department’s Barrier Free Access (BFA) Design Manual, 2008, in lieu of the Americans with Disabilities Act (ADA) Standards for Accessible Design.


Amendment
Type: Amendment
Post Date: 27 Apr, 2017

Add: "or comparable local code or standards" after "Accessible Design"


Amendment
Type: Amendment
Post Date: 27 Apr, 2017

Remove: "Appendix B: Standards"


Equivalency
Type: Equivalency
Post Date: 20 Mar, 2017

The Dutch Standard NEN 1814 is an acceptable equivalent to the American Disabilities Act (ADA) design regulations.


Equivalency
Type: Equivalency
Post Date: 20 Mar, 2017

Previously published as an AAP:
The Alberta Building Code - Barrier-Free Design section 3.8 is an acceptable equivalent to the American Disabilities Act (ADA) design regulations.


Equivalency
Type: Equivalency
Post Date: 20 Mar, 2017

The Chinese Code for Accessibility Design (GB50763-2012) is an acceptable equivalent to the American Disabilities Act (ADA) design regulations. Note, similarly to the application of the ADA to buildings in the US, the code must apply to all buildings. Furthermore, all WELL buildings should be considered ""accessible"" buildings for the purposes of the law.


Equivalency
Type: Equivalency
Post Date: 24 Oct, 2016

The Codi d´Accesibilitat de Catalunya is an acceptable equivalent to the American Disabilities Act (ADA) design regulations. Note, similarly to the application of the ADA to buildings in the US, the code must apply to all buildings. Furthermore, all WELL buildings should be considered "accessible" building for the purposes of the law.


Equivalency
Type: Equivalency
Post Date: 24 Oct, 2016

The Australian Disability Discrimination Act is an acceptable equivalent to the American Disabilities Act (ADA) design regulations. Note, similarly to the application of the ADA to buildings in the US, the Australian Disability Discrimination Act must apply to all buildings. Furthermore, all WELL buildings should be considered "accessible" building for the purposes of the code.


Equivalency
Type: Equivalency
Post Date: 24 Oct, 2016

The French Law regarding PMRs or 'personnes à mobilité réduite' (French Decree No 2006-555 of 17 May 2006, or the latest adoption in effect at the project's registration date) is an acceptable equivalent to the American Disabilities Act (ADA) design regulations. Note, similarly to the application of the ADA to buildings in the US, the code must apply to all buildings. Furthermore, all WELL buildings should be considered "accessible" building for the purposes of the law.


Intent
Type: Intent
Post Date: 24 Oct, 2016

In the Feature description, remove the second paragraph. Replace with the following text:
'Intent: To promote equity by providing buildings that are accessible and usable by people of all physical abilities.'


Amendment
Type: Amendment
Post Date: 24 Oct, 2016

Replace the existing Part 1 text with the following:
"Part 1: Accessibility and Usability

The projects demonstrates compliance with one of the following:
a. Current ADA Standards for Accessible Design
b. ISO 21542:2011 - Building Construction - Accessibility and Usability of the Built Environment, Appendix B: Standards"


Amendment
Type: Amendment
Post Date: 24 Oct, 2016

Change the name of the feature from "ADA Accessible Design Standards" to "Accessible Design"


Equivalency
Type: Equivalency
Post Date: 24 Oct, 2016

The Dutch Integral Accessibility Standard is an accepted equivalent for the American Disabilities Act (ADA) design regulations. Note, similarly to the application of the ADA to buildings in the US, the Dutch Integral Accessibility Standard must apply to all buildings. Furthermore, all WELL buildings should be considered "accessible" building for the purposes of the code.


Equivalency
Type: Equivalency
Post Date: 24 Oct, 2016

The Madrid Technical Building Code for Accessibility is an accepted equivalent for the American Disabilities Act (ADA) design regulations. Note, similarly to the application of the ADA to buildings in the US, the Madrid Technical Building Code for Accessibility must apply to all buildings. Furthermore, all WELL buildings should be considered "accessible" building for the purposes of the code.


Equivalency
Type: Equivalency
Post Date: 24 Oct, 2016

The Building Requirements for Persons with Disabilities from British Columbia Building Code has been deemed equivalent to the ADA for Feature 72. Note, similarly to the application of the ADA to buildings in the US, the BC Building Code must apply to all buildings. Furthermore, all WELL buildings should be considered "accessible" building for the purposes of the code.


Equivalency
Type: Equivalency
Post Date: 23 May, 2016

Hong Kong's Barrier Free Access is an acceptable equivalent to the American Disabilities Act (ADA) design regulations. Note, similarly to the application of the ADA to buildings in the US, the code must apply to all buildings. Furthermore, all WELL buildings should be considered ""accessible"" building for the purposes of the code.


Equivalency
Type: Equivalency
Post Date: 06 May, 2016

Projects in Canada may utilize the Ontarians with Disabilities Act (AODA), as amended January 1, 2015, as an equivalent local standard to the Americans with Disabilities Act (ADA).


Equivalency
Type: Equivalency
Post Date: 06 May, 2016

The UK Part M Volume 2 Standard (Buildings other than dwellings) may be used lieu of the 2010 ADA Standards for Accessible Design as long as the following additional requirements are met:

1. Signage adheres to the requirements of BS 8300: Design of buildings and their approaches to meet the needs of disables people, as referenced within the Part M Volume 2 Standard.
2. Drinking fountains adhere to the requirements of ADA Standards for Accessible Design, Sections 211 and 602 for Drinking Fountains.


Amendment
Type: Amendment
Post Date: 10 Feb, 2016

In Part 1a, change "Buildings" to "Projects"


Feature 73: Ergonomics: visual and physical

Type Description
Amendment
Type: Amendment
Post Date: 07 Jun, 2018

In part description, remove: "At least 30%...of the following". Add: "At 30% of workstations that are at seated height or similar work surfaces, users have the ability to alternate between sitting and standing through one of the following:"


Amendment
Type: Amendment
Post Date: 07 Jun, 2018

In 06 May, 2016 AAP, remove: "For Part 3 (Seat Flexibility)". Add: "For Feature 73, Part 3"


Amendment
Type: Amendment
Post Date: 05 Feb, 2018

For Part 1a, add: ", including laptops," after "screens"


Amendment
Type: Amendment
Post Date: 20 Oct, 2017

For Part 3b, add: "or BIFMA G1 guidelines" after "...HFES 100 standard"


Equivalency
Type: Equivalency
Post Date: 21 Aug, 2017

IS 3663: 1991 - 'Dimensions of Tables and Chairs for Office Purposes (Second Revision)' has been accepted as an alternative for the requirements of Feature 73 Part 3


Equivalency
Type: Equivalency
Post Date: 21 Aug, 2017

Code NPR 1813 has been accepted as an alternative to HFES 100 for the requirements of Feature 73 Part 3.


Amendment
Type: Amendment
Post Date: 26 Jul, 2017

Remove: "employee". Add: "occupant"


Amendment
Type: Amendment
Post Date: 26 Jul, 2017

Remove: "employees" after "Workstations in which". Add: "occupants" after "Workstations in which"


Amendment
Type: Amendment
Post Date: 26 Jul, 2017

In Part 4a, remove: "employees" after "reaching requirements for". Add: "occupants" after "reaching requirements for"


Amendment
Type: Amendment
Post Date: 26 Jul, 2017

In Part 4b, remove: "employees" after "a foot rest to allow". Add: "occupants" "a foot rest to allow"


Equivalency
Type: Equivalency
Post Date: 17 Jul, 2017

The European Standard EN-1335 and Dutch Standard NEN 1812, Type A and Type B only, have been approved as acceptable alternatives to HFES 100. Please note EN-1335 Type C has not been approved as an acceptable alternative.


Alternative Adherence Path
Type: Alternative Adherence Path
Post Date: 27 Apr, 2017

For Feature 73, Part 2, the project may provide height adjustable tables and meeting tables apart from workstation desks to meet the feature requirements.


Alternative Adherence Path
Type: Alternative Adherence Path
Post Date: 27 Apr, 2017

For Feature 73, Part 2, the project may provide a lower threshold of the required initial percentage of sit/stand workstations required by the feature, in conjunction with a future purchase commitment and an educational campaign. The campaign must encourage walking during the working day and highlight the benefits of sit-stand desks. The project must also provide instructions to occupants on how to request a sit-stand desk. The project must provide sit-stand desks in multiple options/styles (for trial use by occupants) and commit to accommodate all occupant requests for a sit-stand desk, even in exceedance of the feature requirement.


Intent
Type: Intent
Post Date: 24 Oct, 2016

In the Feature description, remove the second paragraph. Replace with the following text:
'Intent: To reduce physical strain and maximize ergonomic comfort and safety.'


Alternative Adherence Path
Type: Alternative Adherence Path
Post Date: 06 May, 2016

For Feature 73, Part 3, alternative seat height adjustability and seat depth adjustability ranges may be accepted if the average height of the expected occupants differs significantly from the average height of the US population.


Amendment
Type: Amendment
Post Date: 10 Feb, 2016

In Part 2a, change "Adjustable Height standing desks." to "Adjustable height sit-stand desks."


Amendment
Type: Amendment
Post Date: 10 Feb, 2016

In Part 3b, delete "or BIFMA G1 guidelines."


Verification type
Type: Verification type
Post Date: 10 Feb, 2016

Add Owner Letters of Assurance as required documentation, add on-site spot checks as required verification, remove visual inspections.


Feature 74: Exterior noise intrusion

Type Description
Amendment
Type: Amendment
Post Date: 01 Nov, 2018

For Part 2a, remove: "The sound pressure...peak hour Leq". Add: "Average sound pressure level from outside noise intrusion does not exceed 40 dBA"


Amendment
Type: Amendment
Post Date: 01 Nov, 2018

For Part 2a, remove: "The sound pressure level from outside noise intrusion is less than or equal to 40 dBA based on the peak hour Leq". Add: "Average sound pressure level from outside noise intrusion does not exceed 40 dBA"


Equivalency
Type: Equivalency
Post Date: 06 Jun, 2018

Building Bulletin 93 (BB93) 2015 has been approved as an acceptable method for spaces within education buildings to comply with Feature 74, Part 4 for projects in the United Kingdom. Note that Table 1 of BB93 also includes noise level limits for administration and ancillary spaces and states that “Where a type of room is not listed, the nearest approximation should be used."


Amendment
Type: Amendment
Post Date: 26 Jul, 2017

Remove: "6,000 m²". Add: "1,900 m²"


Amendment
Type: Amendment
Post Date: 26 Jul, 2017

Remove: "6,000 m²". Add: "1,900 m²"


Equivalency
Type: Equivalency
Post Date: 17 Jan, 2017

The Code for Design of Sound Insulation of Civil Buildings’ (B50118-2010) and ‘Environmental Quality Standard for Noise’ (GB3096-2008) have been approved an acceptable method to comply with F74.


Intent
Type: Intent
Post Date: 24 Oct, 2016

In the Feature description, remove the second paragraph. Replace with the following text:
'Intent: To reduce acoustic disruptions by limiting external noise intrusion.'


Feature 75: Internally generated noise

Type Description
Amendment
Type: Amendment
Post Date: 01 Nov, 2018

For Part 3a, remove: ", based on the peak Leq" after "...is less than or equal to 40 dBA"


Amendment
Type: Amendment
Post Date: 01 Nov, 2018

For Part 6a, remove: "Classrooms: less than 35". Add: "Classrooms: maximum noise criteria (NC) of 35"


Amendment
Type: Amendment
Post Date: 01 Nov, 2018

For Part 7a, remove: "7 decibels over the ambient sound level measured a minimum of 15 ft [4.5 m] outside of the entrance to the space". Add: "7 decibels (dBA) above the ambient sound pressure level when measured at a minimum distance of 4.5 m [15 ft] outside of the entrance to the space"


Equivalency
Type: Equivalency
Post Date: 07 Jun, 2018

Building Bulletin 93 (BB93) 2015 has not been accepted as an equivalent for the requirements of Feature 75, Part 6. Specifically, the requirements are performance-based but do not specifically require compliance with a standard to which BB93 may be compared.


Equivalency
Type: Equivalency
Post Date: 29 May, 2018

NEN 5077:2006 has not been accepted as an alternative for the requirements of Feature 75 Part 2. Note that the requirements of Feature 75 list specific noise criteria requirements for space types whereas NEN-EN 5077:2006 takes into account an averaged sound pressure level measurement of a space but does not correlate this result to a noise criteria element specific to space type.


Equivalency
Type: Equivalency
Post Date: 20 Oct, 2017

NEN-EN 15251: 2007 has been accepted as an alternative for the requirements of Feature 75 Part 2.


Verification type
Type: Verification type
Post Date: 20 Oct, 2017

In Verification Method, remove: "Letter of Assurance". Add: "Annotated Document"


Verification type
Type: Verification type
Post Date: 20 Oct, 2017

Remove: "Visual Inspection". Add: "Performance Test"


Equivalency
Type: Equivalency
Post Date: 21 Aug, 2017

NEN-EN 15251:2007 has been accepted as an alternative for the requirements of Feature 75 Part 2.


Amendment
Type: Amendment
Post Date: 27 Apr, 2017

Add: "," after "as well as occupants themselves"


Amendment
Type: Amendment
Post Date: 27 Apr, 2017

Remove: "major" after "occupants themselves can be"


Amendment
Type: Amendment
Post Date: 27 Apr, 2017

Remove: "To reduce acoustic disruptions and increase speech privacy by
creating an acoustic plan and limiting internal noise levels." Add: "To reduce acoustic disruptions from internal noise sources and increase speech privacy."


Amendment
Type: Amendment
Post Date: 27 Apr, 2017

Add: "spaces and potential sources of disruption" after "the following"