Building Services Page 1 of 3
519-837-5615, (revised April 2017)
Radon Mitigation
Certification Form
for all Part 3 buildings and for Part 9 ICI and non-low rise
multi-unit residential buildings
Project address:
Application number:
The individual(s) responsible for the subject building must complete the information
fields below to confirm that the building or addition (see note 1) has been designed
to include the radon mitigation measures listed in the table below pursuant to:
Ontario Building Code (OBC) Division B, and
(which references Environmental Protection Agency (EPA)/625/R-92/016) for
Part 3 buildings, and
OBC Division B, 9.13.4 and (which references Part 6 and
EPA/625/R-92/016) for Part 9 buildings.
By signing this form, the individual(s) acknowledges they are responsible for
carrying out detailed reviews of all radon mitigation measures during construction
and will be required to submit a General Review letter to the City upon completion,
confirming the installation complies with the design. Building inspectors may also
request progress site review reports from this individual(s) to confirm installation is
being monitored during construction.
A. Architectural measures:
(Refer to Section D below, notes 2, 7, and 8)
1. Sealing of walls (e.g. bituminous damp proofing), roofs (e.g. waterproofing)
and floors (e.g. 6 millimetre polyethylene sheet) that are in contact with the
soil, including connections and any penetrations through them.
Name and title:
Registration number:
City: Postal code:
Signature: Date:
B. Mechanical Measure:
(Refer to Section D below, notes 3, 7, and 8)
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2. Pipe rough-in only of an Active Soil Depressurization (ASD) system (see note 4).
Name and title:
Registration number:
City: Postal code:
Signature: Date:
C. Exemption
If this building is exempt from these requirements, indicate the reason
why in the space below (refer to Section D below, note 1):
Name and title:
Registration number:
City: Postal code:
Signature: Date:
D. Notes
1. Radon mitigation measures are not required in the following cases:
a. Additions that do not exceed 50 square metres in building area.
b. Storage /parking garages.
c. Temporary structures (e.g. tents).
d. Unenclosed building or addition, or portions thereof (e.g. pavilion, open-air
viewing stands, grandstands, bleachers).
e. Building or addition, or portions thereof, used only for storage (e.g. self-service
f. Elevated building or addition, or portion thereof, where walls, roofs and floors
are not in contact with the ground (e.g. apartment building entirely above a
parking structure).
For buildings where a future change of use can reasonably be expected, from one
that is exempt from radon mitigation measures to one that requires them (e.g. a
storage warehouse in an industrial strip mall that could turn into a regularly
occupied space use), radon mitigation measures are required for the entire building.
2. Design of architectural measures to be carried out by an Architect or Professional
3. Design of mechanical measures to be carried out by a Professional Engineer.
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Page 3 of 3
4. Since radon concentration varies from site to site, and because it cannot be
measured properly until the building is constructed, a full ASD system with suction
fans will not be required unless long-term testing demonstrates one is necessary.
Instead, the responsible contractor will only be required to install the rough-in soil
gas piping for the ASD system. This includes suction pits and piping below the floor,
as well as capped piping inside the building.
5. Long-term testing is required once construction is complete and the building is
operational. Testing must be carried out by a Canadian National Radon
Proficiency Program (C-NRPP) certified Radon Measurement Professional for a
minimum of 91 days during the winter months, and must follow all applicable
sections in Health Canada Publication 4175, Guide for Radon Measurements in
Public Buildings (schools, hospitals, care facilities, and detention centres). If
concentration levels exceed 200 Becquerels per cubic meter (Bq/m
), a full ASD
system, including fan(s), must be installed.
6. In addition to showing the rough-in drawing details, designers may also wish to
include details showing the piping layout inside the building, fan locations and
specifications, and details on the fan warning device in the event that long-term
testing indicates that a full ASD system needs to be installed. Although some
aspects the system cannot be properly designed until a sub-slab communication
test has been performed onsite (e.g. fan size, fan flow rate, and above slab piping
diameter), submitting preliminary details will provide an opportunity for the plans
examiner to provide preliminary comments.
7. Designs that do not incorporate the two measures listed in the table above will
require a letter from the designer(s) identifying the reasoning for exclusion of that
8. Designs that deviate from the applicable requirements will require a letter from the
designer(s) stating that the proposed level of performance will meet or exceed that
required in the Ontario Building Code and/or EPA/625/R-92/016, and shall list the
standard and/or guideline that was used. Designers will be notified if a formal
Application for an Alternative Solution is required after the permit application has
been reviewed.
Collection of Personal Information
Personal information is being collected and will be used for the purposes of confirming
Ontario Building Code requirements have been met and to communicate with applicant.
Personal information contained in this form and schedules is collected under the authority
of subsection 8(1.1) of the Building Code Act, 1992, and will be used in the administration
and enforcement of the Building Code Act, 1992.
If you have questions about the collection, use or disclosure of this personal information
please call 519.822.1260 extension 2349 or email
Alternate formats of this document are available as per the Accessibility for Ontarians with
Disabilities Act by contacting Building Services at 519-837-5615 or email