Before you can begin the actual design, you have one more major assessment. This is of the jobsite. Structurally and mechanically, you need to know if you can make your design ideas work. Unless you are experienced in "reading" a house and understanding its systems, you may want to enlist the help of a contractor or other knowledgeable person to assist you.
If your bathroom project is new construction or an addition, get involved in the planning before construction begins. Get a copy of all drawings that impact your bathroom design. Make sure that you have all dimensions and mechanical information that relates to the bathroom.
Study the plans for the new space. Find out what is fixed and what is flexible. For example, can an entry door be moved or a window relocated? Or, can an interior wall be increased in width to make it work as a plumbing or "wet" wall?
Although you may or may not be able to inspect the jobsite when designing for new construction, be sure to review the information in Form 6: Jobsite Inspection (discussed below). This helps you review jobsite factors that may influence your design.
Remodeling (Form 6)
If you are working on a project that is a remodeling, you need to know all the structural and mechanical information as well, but it may be harder to find. A thorough and detailed inspection of the area and surrounding rooms will be necessary. If your client has plans or drawings of the space, this will be very useful and can save you time. However, you will need to verify that the rooms were actually built as drawn. You may want to make copies of client drawings, so that you can mark them up as needed.
Prepare for your jobsite inspection by making an appointment with your client. Give them an idea of what you need to do, and make sure that you have access to all the areas of the home. You may do the jobsite inspection at the same time you do the client interview, especially if you have to travel a distance to your client’s home. Wear comfortable clothes that allow you to bend and stretch. Bring a sturdy measuring tape, graph paper (four squares to the inch is recommended), pencils, and a flashlight. A camera will also be useful.
Your jobsite inspection needs to cover several areas: overall knowledge about the bathroom and its relationship to other spaces in the home; structure; mechanical systems; access; construction/ installation planning; and dimensions (discussed in the next section). As with the client interview, if you use a prepared form or outline, you will be more likely to get all the information you need. You can follow Form 6: Jobsite Inspection to gain a thorough analysis of the needed information.
Form 6: Jobsite Inspection
The information on this form needs to be collected through a thorough inspection of the existing structure and/or construction documents. You are looking for detailed information! Some information may appear to repeat some of the questions on other forms, which ask for client ideas and preferences. However, use this form to verify specifics at the actual site.
Begin with a floor plan sketch to understand the relationship of spaces and to make notes about structural and mechanical details. Use graph paper (4 squares to the inch) and sketch at a scale of 1/2" = 1′ 0" or use a metric scale of mm or cm at a ratio of 1:20. See the following questions for additional information to add to your sketch.
note the following information on your bathroom sketch:
• What rooms are above, below, and around the existing bathroom space?
• Can any of the surrounding space be incorporated into the new plan? if so, how much—exactly?
• What walls can be changed—moved, removed, or otherwise altered?
• Which windows and doors are to remain or be reused?
• What doors and windows can be changed—moved, removed, or changed in size or type?
• What fixtures are to remain? Are they to be left in the same location, or can they be moved?
• is there cabinetry that is to be left in place or reused in the new design?
• Which way do the floor joists run? does the floor seem sturdy and stiff?
• Are there load-bearing walls to consider?
• Where does plumbing come into the space?
• Where are the soil stack and other drain/waste/vent pipes?
• Where are existing ducts and registers located? Can these be moved?
• What is the condition of finish materials—floors, walls, and ceilings? Are any of the finish materials to remain unchanged?
• Is there a view from the bathroom? Is the view from the bathroom important? Determine the following additional information about the bathroom:
• Bathroom is on 
Form 6: Jobsite Inspection (Continued)
• Can you relocate any plumbing pipes?
• What is the capacity of the plumbing system?
• What size are the supply pipes? is there adequate water pressure?
• is the water of good quality?
• Will you be able to add additional fixtures, or higher-capacity fixtures to the existing plumbing?
• Where is the water heater? What is its capacity?
• Can the soil stack and other drain/waste/vent pipes be relocated if needed?
• Where are the traps, and what type are they?
• Is the home on a municipal or private sewage system? Are there any concerns about system capacity if the amount of wastewater is increased?
• How many electrical circuits come into the space, and what is the capacity?
• Do the circuits have GFCI (ground fault circuit interrupter) protection?
• Is the wiring in good condition?
• Can existing receptacles be moved?
• If needed, are 240-volt circuits available?
• Where is the electrical service panel for the house?
• Can additional electrical circuits be added if needed?
• How is the existing space heated and cooled? Is the current HVAC (heating, ventilating, and air conditioning) equipment in good condition and adequate in size?
• If there will be an increase in the size of the bathroom, will the HVAC system be adequate?
• Is there an exhaust ventilation system? Is it adequate in size? How is make-up air provided?
• Does all or part of the ventilation system need replacement?
• What size are any doors between the bathroom and the exterior of the home? Are there narrow hallways or sharp turns? Will there be any problems in removing or bringing in large, bulky, and/or heavy fixtures?
• Is this an apartment that must be accessed by an elevator? What are the size limitations of the elevator?
• Is there finished living space above or below the bathroom? Will you be able to open up floors, ceilings, or walls to get access to plumbing, electrical, and HVAC systems?
• Can fixtures, cabinetry, and materials be stored at the jobsite? How much space is there? Is the storage secure and protected from the weather?
• Where will trash be collected?
• How will workers get into and out of the jobsite? Is there carpeting or furniture that needs to be protected?
• Where can workers park? Where can they take breaks or eat lunch?
• What about smoking, playing music, eating, and drinking at the jobsite? What about bathroom facilities for workers’ use?
• Do community or building restrictions apply to construction projects, such as time restrictions for use of an elevator for deliveries, construction equipment access and parking, or notification of neighbors?