Your knowledge as an Architect is paramount for the success of a project. The profession you chose demands an understanding of all seen and unseen elements within the facilities you design. This knowledge is relied upon, not only by clients, but by the other disciplines helping create your vision.

This effort attempts to provide you with basic concepts concerning Plumbing Systems...
THE BASICS
Below is a summary of initial considerations that should become second nature when designing any facility. More detailed explanations of the various items can be viewed by selecting the subjects on the left of this page.

The Importance of Plumbing
Almost every residential real estate agent will tell you that the greatest return on your investment is realized by well designed bathrooms and kitchens. This holds true with other facilities as well. The majority of persons who enter the facilities you design will eventually experience the plumbing. The impression made by your well thought out and expensive lobby may be dampened if toilet facilities are cramped and ordinary. With a little creativity and attention to details, you can continue the design impression throughout the facility.

Another point to remember... There is a good chance that we would not have the opportunity to design these facilities, and more than likely would not even be here, without the health benefits provided by well designed sanitary plumbing systems. (See "Plagues & Epidemics")

Fixture Locations
Avoid locating plumbing fixtures at the following:
GROUND FLOORS
 Exterior walls
 Adjacent to columns
 In front of windows
 On walls having cross bracing
UPPER FLOORS
 On column grids
 Above Electrical rooms
 Above sensitive areas (Operating rooms, Kitchens, etc.)
 Above vaulted or extremely high ceilings
 Exterior walls
 Adjacent to columns
 In front of windows
 On walls having cross bracing
DO locate plumbing fixtures in these arrangements:
 Utilize common walls and chases by setting fixtures back-to-back
 On walls that can easily be larger than the standard 3-5/8" stud
 Stack plumbing chases as often as possible on multi-floor buildings
Fixture Selection
Determine the fixture types in various areas:
 Wall mounted versus floor mounted water closets
 Surface mounted or recessed drinking fountains
 Determine areas where fixtures should have special color or aesthetic design
Chase Spaces
Chases will need to be incorporated into the floor plan to facilitate plumbing system piping. All plumbing fixtures will require pipe chases or at least a minimum 6" stud wall.
Equipment Rooms
Be aware that space must be allocated to house the following:
 Pumps
 Water heaters
 Water treatment equipment
 Domestic and Fire protection Water service entrance
 Do not locate boiler rooms below occupied spaces
 Locate main mechanical room having at least one exterior wall exposure
Roof Drainage
Determine how the roof will be drained.
 Roof drains with interior piping
 Sloped roof with perimeter gutters and downspouts
 Will parapets be incorporated, if so will scuppers be provided.
Project Information
The following information should be obtained and made available to the Plumbing Engineer
 Project scope
 Codes to be followed
 Contact information for Owner representatives and Consultants
 Owners standards or guidelines
 Project schedule
 Project Budget
 Design team names and responsibility description
PLUMBING FIXTURE LOCATIONS

When designing a floor plan, consider the following in order to avoid redesign:
GROUND FLOORS
Exterior walls
There are several problems caused by locating a fixture on an exterior wall. Structural grade beams, cross-bracing and windows present obstacles which can prevent the installation of service piping unless provisions (sometimes costly) are made. Also, remember that in some geographical areas, piping located within an exterior wall may be subjected to freezing temperatures.
A wall chase, wide enough to extend beyond the interior edge of grade beams and/or cross-bracing, can be provided behind fixtures to accommodate piping, however, this is not a very economical way to utilize square footage. In some cases, waste and vent piping can be installed in walls perpendicular to the exterior wall and adjacent to the fixtures, but this arrangement is limited to only certain types of fixtures.
Always be aware of window locations when placing fixtures. Fixtures may be located below windows, only when the bottom seal is at least 48" above the floor. The wall beneath the window will also require additional reinforcement to compensate for holes that will have to be cut in studs to horizontally route vent and water piping around the window.
If your creativity deserts you and you must locate fixtures on exterior walls, be sure to coordinate with the project Plumbing Designer before proceeding with your design.
Adjacent to columns
The structural foundation below ground floor columns will be larger than the column itself. This can prevent piping from serving the fixture. There seems to be a tendency to corral plumbing fixtures with columns to supposedly save space. However, more space may be required to facilitate a fixture located adjacent to a column than a fixture located where there will be no structure interference.

UPPER FLOORS
Columns, Column Grids, Exterior Walls, Windows
Upper floors provide the same problems for plumbing fixtures as the ground floor with the added bonus of beams and joists. Nine times out of ten, beams will be located on column grid lines.
As you are laying out walls and placing plumbing fixtures, visualize the structural members that will be beneath the floor slab and remember that drain piping serving the fixtures will be penetrating the slab from below.
Sensitive Areas on Lower Floor
Electrical Codes, Health Department Regulations and Hospital Licensing Requirements do not allow Plumbing piping to be located above certain areas, (Electrical Rooms, Food Preparation, Serving, Dining or Storage, Operating Rooms, Nurseries, I.C.U., and other Critical Care Areas) unless special precautions are provided. These Special Precautions usually require the installation of drain pans below all drainage piping above these areas. Obviously, providing drain pans can be costly and will utilize a significant amount of ceiling space. Be aware of the space immediately below the floor you are designing and avoid locating fixtures or equipment served by plumbing above sensitive areas.
Ceiling Space Limitations on Lower Floor
Consider space availability within the ceiling directly below fixtures and equipment. Vaulted ceilings in a lobby, high ceilings in Operating Rooms, etc., can prevent the installation of piping.

SUMMARY
Always be aware of the space demands required by plumbing fixtures. Do not use the structural grid as a homing device for laying out fixtures and restrooms. Think three-dimensionally and visualize spaces above and below the areas you are developing. If you prepare a floor plan without these considerations, something will have to change: The Structural Engineer will have to redesign the structure; or You will have to provide uneconomical, large, wall spaces; or You will have to relocate fixtures and redesign your floor plan. Much of the time spent on your preliminary layout will have been wasted. By realizing the various components of a building while you are in conceptual design, can insure your control of the finished product and save time for everyone.
PLUMBING FIXTURE SELECTION
An Architect must have at least a basic understanding of the various types of plumbing fixtures that are available and also with their installation requirements.

WHY IS IT IMPORTANT FOR AN ARCHITECT TO HAVE THIS KNOWLEDGE?
Aesthetic Considerations
 Plumbing fixture manufacturers have become extremely innovative in providing a wide range of colors, finishes, shapes and even themes for fixtures, faucets and trim. Taking advantage of these options and incorporating them into your design can create pleasing environments for your clients. Since the plumbing engineer may not be aware of the interior finishes or design impressions that the Architect is planning to implement, it is necessary that you become involved with these selections.

Functionality
Along with variety in appearance, there are even more choices available when it comes to deciding which fixtures are best suited for specific applications.
 Fixture designs are available to accommodate handicap accessibility, vandalism concerns, patient care, laboratory procedures, and many other special use requirements.
 Again, since the plumbing engineer may not be in contact with the client, the Architect should always determine how fixtures will be utilized and verify any special needs that are required for the various users.
 A graphic, yet real example of how critical the selection of plumbing fixtures can be, is this incident that took place in a hospital emergency area...A lady in early term pregnancy visited the hospital when she realized that something inside her did not "feel right". Upon entering the emergency suite, she attempted to use the public restroom. While on the toilet, she miscarried. The lady stood hoping to get aid, which in turn caused the toilet to automatically flush. The water closet was equipped with an infrared sensor flush valve. Obviously, this is a drastic case, but it reveals the importance of why we, as professionals, must never underestimate our responsibility to pay close attention to details.
Installation
The Architect has the responsibility of deciding where fixtures are placed within a floor plan. Knowing basic installation requirements for the most common plumbing fixtures can help prevent redesigning a layout or casework due to locating a fixture in such a way that does not allow proper installation.
 Some requirements are common to all plumbing fixtures. A brief explanation of these is provided on the page - Fixture Locations .

The following section describes requirements that are particular to various types of fixtures.
FIXTURE TYPES
All plumbing fixtures are not created equal. They should be chosen based on code requirements, user needs, aesthetic preference, construction conditions, and budget considerations. The following overviews the most common fixtures:
(Note: Security/Prison fixtures are not addressed ).
Water Closets
 There are basically two types of water closets; wall-mounted and floor-mounted. Both are available with either flush tanks or flush valves and can be selected to meet A.D.A. requirements. All water closets for public use must have elongated bowls and open-front seats.
 Wall-Mounted toilets require a carrier that supports the fixture from the rear with bolts. The more stable type of carrier is bolted to the floor, keeping the weight of the fixture and its user from being transmitted to the wall. A wall chase is required to facilitate the carrier. Generally, wall-mounted fixtures are more expensive than floor-mounted. However, they provide better sanitary conditions due to the fact that the floor beneath them can be easily cleaned. These fixtures are better suited for multi-story buildings since they require fewer floor penetrations than the floor-mounted type and will allow more economical waste and vent piping systems. Most wall-mounted water closets are designed to support a 300 pound load.
 Floor-Mounted toilets require two floor penetrations for piping. One for the vent which will be located within the wall and one for the drain which will be located 10-12 inches from the finished wall face. The bowl is secured to the floor with bolts. These fixtures will require less chase space than the wall-mounted type. Since the bowl sets on the floor, maintaining sanitary conditions around its base can be difficult.
 Flush valves should be provided for public use. They allow flushing to be achieved at closer intervals than flush tanks since there is no time needed to refill the tank. Bowl contents will generally be removed more successfully than with flush tanks. The flush valve is more expensive than the tank since it requires a larger water supply and higher pressure to function properly. Flush tanks provide a more residential appearance but will require more maintenance.
 Toilet seats are available in various types and with many useful options. As mentioned above, seats for public use should have open fronts to promote better sanitary conditions. Consider specifying seats with checks and self-sustaining hinges. These options will prevent the seat from slamming against the flushing device or wall when raised and also allow the seat to remain in an upright position while the bowl is being cleaned. Seat covers should not be specified for public use.
Urinals
 There are basically two types of urinals; wall-mounted and floor-mounted. Both utilize flush valves. All urinals that are required to meet A.D.A. must have elongated bowls.
 Wall-Mounted urinals require a carrier that supports the fixture from the rear with bolts. The more stable type of carrier is bolted to the floor, keeping the weight of the fixture from being transmitted to the wall. A wall chase is required to facilitate the carrier. These fixtures are better suited for multi-story buildings since they require fewer floor penetrations than the floor-mounted type and will allow more economical waste and vent piping systems.
 Floor-Mounted urinals must be provided with electronic sensor type flush valves in order to meet A.D.A. actuator height requirements. Since the bowl sets on the floor, maintaining sanitary conditions around its base can be difficult.
Lavatories
 Lavatories can be wall-mounted, counter-mounted, and molded integral with counter tops. All can be selected to meet A.D.A. and have similar piping requirements.

SUMMARY
This article will hopefully encourage the Architect to become involved with Plumbing fixture selection and provide him or her with basic knowledge to do this. A Plumbing fixture is more than just a symbol on a floor plan. As you should gather from the brief descriptions above, there are specific requirements and considerations that must be given to each type of fixture on every project. Coordinate with the Users and Plumbing Engineer during the preliminary phase of your design and discuss the needs and available options. By doing this, you will be serving your clients with the professionalism they expect and deserve.
Plumbing Chase Spaces and Partition Sizes
Architects commonly lose control over a design by overlooking plumbing space requirements.
REALITIES OF CONSTRUCTION
A contractors task is to build based upon an Architects documents. When walls and chases are not designed to accommodate piping and supports, the contractor will be forced to increase their size. As soon as this occurs, the Architects dimensions become jeopardized. A few inches may not matter in some cases. However, floor plans that must meet code required square footages and clearances, such as handicap access and hospital licensing, can become non-compliant, necessitating costly re-design.
Most Clients expect an Architect to know how to accommodate the various components to be installed within a facility. Your Client should not be informed by a contractor that the Architect did not provide enough space. When this occurs, two things are lessened: the dimensions of a room and the Clients confidence in the Architects knowledge.

Frequent Misconceptions
MYTH - Plumbing services for most fixtures such as lavatories, sinks and drinking fountains will fit within a standard (3.625 in, 9.2cm) stud wall...
REALITY - This is true only when all of the following conditions are met: The contractor is perfect when measuring pipe locations prior to installation of partitions; There are no other plumbing fixtures on the same wall; There is no structural member beneath the wall, such as a joist or beam; The fixture is free-standing and does not require a support within the wall; The piping for the fixture is not serving fixtures on floors above.
As you can see, it can be a mistake to assume that a standard stud wall will be sufficient in every situation.

MYTH - Plumbing piping can be easily installed within cinder blocks.
REALITY - Piping is installed prior to constructing walls. Building a block wall around waste, vent and water piping is difficult, time consuming, frustrating and costly. However, it can be done by breaking the blocks in half and mortoring one side to cover the pipe. Unfortunately, concrete is corrosive to piping and metal supports, eventually destroying them unless they are provided with a protective coating. This arrangement also destroys the natural seam pattern of a block wall. A furring strip or other covering must be provided on the mortor face to hide wall finish inconsistencies. A more professional design can be achieved by providing a clear space behind or in front of a cinder block wall, allowing proper installation of piping and supports.

MYTH - The plumber can always find a way to install piping to fixtures by using a little imagination.
REALITY - Plumbing codes, physical space demands and economics limit the arrangements possible.
An Architect must never assume that a fixture can be installed at any location. An Architect must always know the requirements dictated by the needs of various fixtures.

MYTH - A chase or partition size provided on a previous project will be sufficient for any project.
REALITY - All sinks, lavatories, water closets, drinking fountains, etc. are not created equal. Space and piping requirements can vary significantly based upon the type of fixture specified. For example; Electric

SPACES FOR PLUMBING SYSTEMS
An important fact to be aware of is that plumbing equipment can not always share the same mechanical rooms provided for HVAC equipment (i.e., air handling units, chillers). Therefore, it is very important to coordinate with the plumbing engineer to insure that a floor plan allocates the additional real estate required. Do not assume that a single mechanical room on a floor will suffice.

Basic Systems
Most commercial facilities will require spaces for the following:
 Domestic Water Service Entrance
 Fire Protection Water Service Entrance
 Natural Gas Service Entrance
 Domestic Water Heating Equipment

DOMESTIC and fire protection water supplies for a building require an accessible space located at the ground floor having at least one exterior wall. (An exception to this would be when a building has a sub-grade level). NFPA and most plumbing codes do not allow main water services to extend more than five feet from the exterior wall below a building slab on grade. Access is required to shut-off valves and drains. The fire protection water riser will need sufficient room allowing local fire officials to inspect and test the system.

NATURAL gas piping is not allowed beneath a slab on grade unless it is within a trench having a removable cover. The service should enter above grade through an exterior wall, and preferably into the mechanical room housing gas fired space heating/domestic water boilers. When gas piping has to be concealed upon entering a building, such as within a chase, special provisions must be provided to allow venting of gas in the event a leak occurs.

WATER heating equipment for domestic purposes are most commonly gas/oil fired or electrically powered. Gas/oil fired heaters require a source of outside air to promote combustion and a safe location to exhaust fumes to the exterior via a flue vent. These requirements are best met when the equipment is located within a room having an exterior wall and a roof. Placing gas/oil fired heaters beneath occupied upper floors should be avoided. There is more flexibility in locating electrically powered heaters since they do not have the above mentioned requirements. However, the utlity cost of electricity is usually greater than that of gas/oil. All water heaters should be located with safety, service access, and energy efficiency in mind.

Additional Systems
Supplementary equipment may be included within plumbing systems requiring space provisions:
 Domestic Water Pumps
 Fire Protection Water Pumps
 Water Treating Equipment
 Medical Gas Equipment

DOMESTIC water pumping systems are required in buildings when the municipal water system can not provide sufficient pressure required to operate fixtures and equipment. Most buildings over three stories in height will require a booster pumping system. Normally, the most efficient and economical location for a domestic water pump room will be at an area within the ground floor having at least one exterior wall. Some installations may require a water storage tank to provide an emergency supply of water and/or to physically separate the pumping system from the municipal system. Climate conditions, size of tank, availability of site space and avalibility of interior space will determine whether to place the storage inside or outside the building. Locating a domestic pumping system within a basement should be avoided in areas subject to flooding.

FIRE water pumping systems are required in buildings when the municipal water system can not provide sufficient pressure required to operate sprinkler and/or standpipe systems. Most buildings that require a NFPA 14 compliant standpipe system will require a booster pumping system. The most common fire pump systems are powered by an electric motor or a diesel engine. An electri

"FLAT" ROOFS WITH DRAINS AND INTERIOR DOWNSPOUTS
Basic Considerations
 The first factor to analyze before an internal roof drainage system is considered, is to verify that there is a means to discharge storm water into an underground piping system or drainage ditch. If roof drain piping can not be routed from the building below ground, the pipe will need to discharge above grade through the exterior walls. You can imagine how six, eight or ten inch diameter holes would look dotting the face of your exterior walls. (Not to mention the streams of water pouring out of them during a rain).
In the event below grade discharge is not possible, consider utilizing perimeter roof gutters and exterior downspouts. Gutters and downspouts will allow you to have more control of discharge points and will negate the necessity of chase spaces within the building for interior piping.
 Determine whether a parapet will be provided. Building Codes require a means of disposing rain water from a roof in the event a primary roof drainage system does not function. The inclusion of a parapet causes a decision to be made concerning the method by which storm water emergency overflow will be achieved.
 Evaluate the type of roof system to be specified. Various manufactures have defined slope and drain placement requirements included within their system warranty. The physical size, local rainfall rates and the number & size of interior leaders you can be facilitated within the floor plans, determine the quantity of roof drains that will be required. Also, remember that large roof areas may be drained more economically by sloping the roof structure, thereby limiting the depth of insulation. Acquire input from the Structural Engineer to determine if this is an option to consider.
To Scupper or Not to Scupper
As previously mentioned, parapets introduce a need to protect the roof from the build-up of storm water on a roof in the event of drainage system malfunction. There are two methods of meeting this requirement, Providing the proper number of scuppers through the parapet or Providing an additional system of roof drains and leader piping.
 Scuppers are by far the most economical of the two. Consult the applicable Building Code for proper sizing and placement of scuppers and remember that the bottom of scupper openings must not be more than two inches above the low point of the roof. This will affect the location of roof drains and the arrangement by which the roof is sloped. An exception can be made to the two inch requirement by designing the roof structure with the capacity to support the weight of water that is contained on the roof before the scuppers provide relief.
 In the event scuppers are not feasible, a secondary system of roof drains and internal leaders must be designed. This secondary system creates a few logistical problems and can be expensive. The Standard Plumbing Code as well as the International Plumbing Code requires that the secondary system piping be sized significantly larger than the primary system. All of the major Codes require that the discharge of the secondary system be independent of the primary system. This means that the secondary leaders will have to discharge through the exterior walls above grade.
Please consider the logistic, economical and aesthetic consequences when determining the method of emergency overflow and consult with the Plumbing Engineer before you make a final decision.
PERIMETER GUTTERS WITH EXTERIOR DOWNSPOUTS
Obviously, the construction type and height of the building will limit the use of perimeter gutters and downspouts. However, when they are provided, consider the following:
 Discharge of downspouts should not flow over pedestrian walkways (Especially in areas subject to freezing temperatures)
 Provide a sufficient quantity of downspouts to limit the slope of gutters and t