The diverse character of sanitary fittings necessitates considerable difference in the location and arrangement of the rooms in which they are placed, but certain general rules are applicable in every case. The most important points to be observed are plenty of light and, if possible, of direct sunlight, ample means of ventilation, impervious surfaces (at any rate, immediately around the fittings), convenience of position and plan, and (for certain fittings) privacy. If the rooms for the different fittings can be grouped together in one part of the building, although, perhaps, in two or more stories, it will be not only economical, but advantageous in other respects.

Light

No sanitary fitting ought to be fixed in any room which is not properly lit by one or more windows or toplights. Borrowed lights ought not to be tolerated as the sole means of lighting sanitary rooms. The windows or toplights must be made to open, and must be of ample size, and will be all the better if exposed to direct sunlight during a considerable part of the day. The common allowance of 1 square foot of window space to every 10 square feet of floor area is far too little for rooms containing sanitary fittings, even if the net area of the glass is taken as the basis of the calculation. For example, many water-closets measure only about 5 ft. 6 in. by 2 ft. 6 in., giving an area therefore of 13 3/4 square feet; according to the rule, a window with a net area of about 1 1/3 square feet ought to suffice. We need hardly point out that such a small window would be quite unsatisfactory; if placed near the ceiling it would not light the closet-basin or the floor, and if placed in the lower half of the room it would be of little use for ventilation. What is wanted is a window extending practically up to the ceiling, so that the air in the upper part of the room can be thoroughly changed by opening the window, and extending so low as to throw a direct light on the floor of the room and on the closet-basin and seat. The width of the window ought to be such that the light is well distributed throughout the room. The area of the window in a small water-closet or housemaid's closet ought to be at least half the area of the floor. The proportion need not be so great for larger rooms, but much will depend upon the shape of the room and the position of the window or windows. The Glasgow building regulations require the window of a water-closet to have a minimum area of six square feet, and at least one-half of the window must be made to open. In London an area of two square feet is considered sufficient, if the whole is made to open.