DIR1998-00007 CITY OF TIGARD
Community Development
Shaping A Better Community
MEMORANDUM
CITY OF TIGARD
TO: Planning Director Interpretation File
FROM: Jim Hendryx ,)A,d0 -
DATE: December 24, 1998
SUBJECT: Floor Area Ratio (FAR) Interpretation
The purpose of this memo is to provide an interpretation of various terms used in determining the
floor area ratio within the Mixed Use Employment (MUE) zone. Specific questions have been
raised that this interpretation is meant to address.
It is important to recognize that MUE zone was established to encourage mixed use development
within the Tigard Triangle. Design standards were imposed to ensure high quality development
that is pedestrian oriented.
The Community Development Code (Ordinance 1800) has the following definitions:
18.120.20 Meaning of Common Words
18.120.21 72. "Floor area" - The gross horizontal area, under a roof, of all floors of a building,
measured from the exterior walls, excluding vents, shafts, courts and space devoted
to off - street parking. The floor area of a building, or portion thereof, not provided with
surrounding exterior walls shall be the usable area under the horizontal projection of
the roof or floor above.
73. "Floor area ratio" - The gross floor area of all buildings or structures on a lot
divided by the total lot area.
How is the floor area measured? Floor area is calculated by measuring from the outside of exterior
walls for each floor of a building. Areas utilized for vents, shafts, courts, and off street parking are
deducted to provide the net floor area.
What are vents, shafts, and courts? Vents, including ducts, are those features necessary to move
air into and out of a building that extend through the roof. Shafts include stairwells, elevators, and
other such features necessary to support the operation of a building. Courts are areas that are
open to the sky and not enclosed by a roof. Area devoted to vents, shafts, and courts can be
•
deducted from the total square footage of a building for the purpose of determining the floor area
- Patio. The floor area for each story is calculated separately, deducting vents, shafts, courts, etc.
areas devoted to equipment that support the operation of a building, such as the furnace room,
elevator equipment room, etc., can be deducted from the total square footage of a building for the
purpose of determining the floor area ratio. ADA rescue recovery rooms included in a stairwell are
not included in the square footage.
Outdoor covered patios are not included in the total square footage of a building unless it's
enclosed on three or more sides.
Open area above the main floor level of an atrium or entrance is not included in the total square
footage of a building. However the floor level area is included in the FAR.
The FAR includes the net floor area of all buildings or structures on a lot divided by the total lot
area. The CDC defines lot area as "the total horizontal area within the lot lines of a lot, exclusive of
public and private roads and access easements to other property or the private driveway area of a
flag lot." The FAR is calculated on the lot area after dedications for public rights -of -way.
FAR CALCULATION
Deduct the square
footage for each floor
of the stairwell
- M Deduct the square
*-----.---.---*-- 1
1
faotage
of the shaft for each floor , , , ,p 9 1
=' Gross lot area 24,000 sq. ft.
Dedication of P.O.W. 4,000 sq. ft.
Lot area 20,000 sq. ft.
Deduct the square FAR (.40) 8,000 sq. ft.
footage of the Stairwell 600 sq. ft.
equipment room Equipment room 400 sq. ft.
Shaft 300 sq. ft.
Allowed square footage 9,300 sq. ft.
JT ROTH CONST Fax :5036240239 Dec 17 '98 14:00 P. 01/01
jaxswmo
From: Tim Roth To: Jim Hendryx
Roth Construction, Inc_ Company: City of Tigard
12600 S.W. 72' suite 200 Phone #: 639 -4171
Tigard, Or. 97223 Fax #: 684 -7297
CCB #31700
503/639 -2639 Date: Dec. 17 19 98 .
503/624 -0239 far Total pages (including cover) 1 .
RE: 12755 S.W. 69
SDR 98 -0016 - Conditions of approval article # 9
I addressed a question to Ms. Julia Hajduk, regarding the F.A.R. as it applies in. the M.U.E.
zoning, and she suggested that I might want to request clarification from you.
The maximum floor area ratio, to not exceed 0.40 of the total site, as stated in the development
code # 18.67.040, is not clear as to exactly what square footage of a designed structure may be
excluded from the total building design in order to achieve the 40% coverage. The development
code does not provide an exact definition for `floor area ratio ", and I question whether the
definition of "floor area" is adequate to apply in defining floor area ratio. Please consider the
following concerns:
1 _ The definition of floor area was established prior to the "floor area ratio" concept
being applied to development projects.
2. Several modifications have been made to the code since the floor area definition was
established and the floor area definition was not modified to address the changes.
3. Neither Julia nor I could interpret what is meant by the last sentence of the floor area
definition "The floor area of a building, or portion thereof shall be the usable area
under the horizontal projection of the roof or the floor above.". Especially since the
sentence preceding is somewhat contradictory.
If the operative word is `useable" then I question what is `not useable"
4
*mechanical chase -ways? 0 0A ( k
'elevator shaft and elevator equipment room? ‘ � S
*second floor of the stairwell shaft?
'second floor of the entry foyer where the foyer is opened through to the ceiling of
the roof truss?
`the area of the framed exterior wall (6" around the perimeter)?
'the rescue recovery room required at the top of the stairs of the second floor,
required for ADA, which is to be left un -used or occupied.
I would appreciate your response on the interpretation on this issue. Since my project square
footage is dependent on the FAR. definition I am somewhat halted until I receive your
response. Thank you for giving this your immediate attention.
Respec i y
Ai ,Z
J. . 'r• r.
DATE: 12/24/1998
CODE SECTIONS: 18.120.20
18.120.21
18.620 9 (
1 TOPIC :1 Floor Area Ratio (FAR) Terms
INTERPRETATION: The purpose of this is to provide an interpretation of various terms used in determining the
floor area ratio within the Mixed Use Employment (MUE) zone. Specific questions have
been raised that this interpretation is meant to address.
It is important to recognize that MUE zone was established to encourage mixed use
development within the Tigard Triangle. Design standards were imposed to ensure high
quality development that is pedestrian oriented. The Community Development Code
(Ordinance 1800) has the following definitions:
18.120.20 Meaning of Common Words
18.120.21 72. "Floor area" - The gross horizontal area, under a roof, of all floors of a
building, measured from the exterior walls, excluding vents, shafts, courts and space
devoted to off - street parking. The floor area of a building, or portion thereof, not provided
with surrounding exterior walls shall be the usable area under the horizontal projection of
the roof or floor above.
18.120.21 73. "Floor area ratio" - The gross floor area of all buildings or structures on a
lot divided by the total lot area.
How is the floor area measured? Floor area is calculated by measuring from the outside
of exterior walls for each floor of a building. Areas utilized for vents, shafts, courts, and off-
street parking are deducted to provide the net floor area.
What are vents, shafts, and courts? Vents, including ducts, are those features necessary
to move air into and out of a building that extend through the roof. Shafts include
stairwells, elevators, and other such features necessary to support the operation of a
building. Courts are areas that are open to the sky and not enclosed by a roof. Area
devoted to vents, shafts, and courts can be deducted from the total square footage of a
building for the purpose of determining the floor area ratio. The floor area for each story is
calculated separately, deducting vents, shafts, courts, etc.
Areas devoted to equipment that support the operation of a building, such as the furnace
room, elevator equipment room, etc., can be deducted from the total square footage of a
building for the purpose of determining the floor area ratio. ADA rescue recovery rooms
included in a stairwell are not included in the square footage.
Outdoor covered patios are not included in the total square footage of a building unless it's
enclosed on three or more sides.
Open area above the main floor level of an atrium or entrance is not included in the total
square footage of a building. However, the floor level area is included in the FAR.
The FAR includes the net floor area of all buildings or structures on a lot divided by the
total lot area. The CDC defines lot area as "the total horizontal area within the lot lines of a
lot, exclusive to public and private roads and access easements to other property or the
private driveway area of a flag lot." The FAR is calculated on the lot area after dedications
for public rights -of -way.