121211 lt Cutter & Ziskind Plumbing Calc package
December 11, 2012
Mr. Louis Hasbrouck
Building Commissioner
Town of Northampton
212 Main Street
Northampton, MA 01060
Re: Cutter & Ziskind – Renovation Project
Plumbing fixture count and accessibility requirements – 1st floor and basement
Dear Mr. Hasbrouck:
This letter is based on the Massachusetts State Building Code, 8th Edition (MSBC), 521 CMR Massachusetts
Architectural Access Board (MAAB), and 248 CMR: Uniform State Plumbing Code (248 CMR). The purpose of
this letter is to outline the design team’s proposed approach with regard to plumbing fixture counts.
PLUMBING FIXTURE COUNT
The following approach has been developed by the design team in order to provide an adequate number of
plumbing fixtures while addressing the challenges associated with providing an increased number of plumbing
fixtures in an existing building.
Ratio of Women to Men
248 CMR Section 10.10.18.b.e normally requires that a ratio of 50% for each sex be used to define fixture counts;
the plumbing inspector must otherwise be notified in writing.
Because Smith College is a Women’s school and the faculty/staff are predominantly women, the design team
proposes to use a ratio of 80% women in determining the required number of fixtures (in public spaces). This
ratio accounts for some utilization of the building by male faculty/staff and visitors.
In the residential portions of the building however, the occupants will be 100% female. For this reason, the design
team proposes to provide plumbing fixtures allocated 100% to female use.
Program Occupant Load
First Floor
The design team has chosen to utilize a programmatic occupant load in determining the required number of
plumbing fixtures for the 1st floor of the Cutter & Ziskind house building.
Various utilization scenarios have been developed in order to determine a realistic program occupant load; each
scenario considers usage of the dining, office, and ancillary assembly spaces. During this process it was
recognized that, in general, these spaces will not be simultaneously 100% utilized. Therefore, the design team
proposes a program occupant load of 242 persons as the basis of the 1st floor plumbing fixture calculation; this
program occupant load is based upon 240 persons in the dining area and 2 persons in the staff office area (see
attached drawing). It should be noted that the kitchen staff (11 people) are provided with a single user restroom
in the kitchen area.
December 11, 2012
Page 2 of 5
Further, it should be recognized that a significant number (approximately half) of the female occupants utilizing
the dining area will be residents of the building; these occupants will have access to the residential restrooms on
the 2nd and 3rd floors. For this reason, the design team is proposing to further reduce the 1st floor program
occupant load by assuming half of the dining hall occupants are non-residents and will only have access to the
public toilet facilities. Considering this reduction, the proposed 1st floor program occupant load is as follows:
242 x 0.8 = 193.6 female occupants
193.6 ÷ 2 = 96.8 female non-resident occupants
242 x 0.2 = 48.4 male occupants
Total 1st Floor program occupant load:
· 97 females
· 49 males
Basement Level
The design team has chosen to utilize a programmatic occupant load in determining the required number of
plumbing fixtures for the basement level of the Cutter & Ziskind house building.
The basement level of the Cutter & Ziskind house building is comprised of 2 library/lounge areas and various
mechanical/storage areas. The maximum expected occupancy in the 2 library/lounge areas is approximately 18
persons (see attached drawing); the mechanical/storage areas are not considered to be normally occupied and
are therefore not included in the program occupant load.
Total Basement Level program occupant load:
· 15 females
· 3 males
December 11, 2012
Page 3 of 5
Required Plumbing Fixtures
First Floor
Plumbing Fixture Count - 1st Floor
MPC Requirement Req’d #
of Toilet
Fixtures
Req’d #
of
Urinals
Req’d # of
Lavatories
Req’d #
of
Drinking
Fountains Table 1 (Section 10.10)
Toilets Lavatories Drinking
Fountains
Cafeteria
Female* 1 per 30
1 per 200 N/A
3.20 N/A 0.48
N/A 96
Male* 1 per 60,
50% urinals 0.80 N/A 0.48
48
Office Space
Female 1 per 20
1 per 50 1 per floor
0.05 N/A 0.02
1 1
Male 1 per 25,
33% urinals 0.04 N/A 0.02
1
Total Female Fixtures: 4 N/A 1
1
Total Male Fixtures: 1 1
*Please see above for determination of program occupant load and ratio of men to women.
Basement Level
Plumbing Fixture Count - Basement
MPC Requirement Req’d #
of Toilet
Fixtures
Req’d #
of
Urinals
Req’d # of
Lavatories
Req’d #
of
Drinking
Fountains
Table 1 (Section 10.10)
Toilets Lavatories Drinking
Fountains
Library/
Lounge
Female*
1 per 50
1 per 60 At least 1
0.30 N/A 0.08
1.00
15
Male* 1 per 100,
33% urinals 0.03 N/A 0.02
3
Total Female Fixtures: 1 N/A 1
1
Total Male Fixtures: 1 1
*Please see the attached narrative for determination of program occupant load and ratio of men to women.
December 11, 2012
Page 4 of 5
Number of Plumbing Fixtures Provided
First Floor
The proposed layout provides 4 accessible, unisex single user toilet rooms. For the purposes of this analysis, 3
of the single user toilet rooms will be considered for female use and the remaining single user toilet room will be
considered for male use. An additional female restroom is provided on the basement level; 1 such toilet fixture
and 1 lavatory will be used to meet the 1st floor requirements. Therefore, the required number of fixtures is
provided for the 1st floor occupants.
Basement Level
The proposed layout provides 4 toilet fixtures and 3 lavatories; 1 toilet fixture and 1 lavatory are located in an
accessible, unisex single user toilet room. For the purposes of this analysis, the fixtures provided in the multi-user
restroom will be considered for female use and the remaining single user toilet room will be considered for male
use. Therefore, the required number of fixtures is provided for the basement level occupants.
CONCLUSION
It is our opinion that the proposed 1st floor and basement level layouts provide an adequate number of plumbing
fixtures for the expected occupant loads. The 2nd and 3rd floor layouts, while not discussed in this letter, provide
an adequate number of toilet, lavatory, and bathing fixtures, based upon expected the number of residents on
each floor. The design team respectfully requests approval to provide the number of plumbing fixtures on the 1st
floor and basement level as described above.
If you have any questions or comments, please do not hesitate to contact me.
Prepared by:
COSENTINI ASSOCIATES, INC.
Code Consulting and Fire Engineering Services
Donald Havener | Fire Protection Engineer
Phone: 617-494-9090 | Fax: 617-494-9292 | Direct Dial: 617-234-1848
dhavener@cosentini-ma.com
Cosentini Associates, Inc. - A Tetra Tech Company
Building 200, 2nd Floor
One Kendall Square, Suite B2204
Cambridge, MA 02139-1571
December 11, 2012
Page 5 of 5
Reviewed by:
COSENTINI ASSOCIATES, INC.
Code Consulting and Fire Engineering Services
Caitlin E. Gamache, P.E. | Sr. Fire Protection Engineer
Phone: 617-494-9090 | Fax: 617-494-9292 | Direct: 617-234-1829
cgamache@cosentini-ma.com