How high should a braille sign be mounted?

Tactile characters sit at least 48 inches (1220 mm) above the floor measured from the baseline of the lowest character, and no more than 60 inches (1525 mm) measured from the baseline of the highest (703.4.1). Elevator car controls are excepted.

Which side of the door does a braille sign go on?

Alongside the door on the latch side, not on the door itself — a door standing open takes its sign with it. At double doors with one active leaf the sign goes on the inactive leaf (703.4.2).

Signs

Where braille goes on a sign, and where the sign goes

Below the text and 3/8 inch clear of anything raised; the sign itself 48 to 60 inches off the floor, on the latch side of the door.

A sign made to every dimension in Table 703.3.1 still fails if it is mounted on the wrong side of the door, and a reader who cannot find a sign is no better off than one who cannot read it. Placement is half the standard.

Where the braille sits on the sign (703.3.2)
Rule	Clause	Reason
Braille shall be positioned below the corresponding text, and below all of it where the text runs to more than one line	703.3.2	So a reader who finds the raised text knows where the braille is without hunting. The predictability is the point.
Braille shall be separated 3/8 inch (9.5 mm) minimum from any other tactile characters and from raised borders and decorative elements	703.3.2	A decorative raised border closer than 3/8 inch is read as part of the braille. On elevator car controls the separation drops to 3/16 inch (4.8 mm), and the braille may sit beside the control rather than below it.

Where the sign sits in the building (703.4)
Rule	Clause	Reason
Tactile characters shall be 48 inches (1220 mm) minimum above the floor, measured from the baseline of the lowest character, and 60 inches (1525 mm) maximum, measured from the baseline of the highest	703.4.1	Two different measurements, taken from two different characters. A tall sign can put its lowest line under 48 inches while its highest is still under 60, and fail on the first. Elevator car controls are excepted.
At a door, the sign goes alongside it on the latch side	703.4.2	Not on the door. A door that is standing open takes its sign with it, and a reader feeling for the sign finds the doorway. Where there is no wall at the latch side, the sign goes on the nearest adjacent wall.
At double doors with one active leaf the sign goes on the inactive leaf; with two active leaves it goes to the right of the right-hand door	703.4.2	The inactive leaf is the one that stays shut, so the sign stays put — the same reasoning as the latch side, applied to the only case where a sign on a door is allowed.
A clear floor space of 18 by 18 inches (455 by 455 mm) minimum, centred on the tactile characters, beyond the arc of any door swing between closed and 45 degrees	703.4.2	Room to stand and read without being hit by the door. Signs are permitted on the push side of a door that has a closer and no hold-open device.

The height is two measurements, not one

Two different measurements, taken from two different characters. A tall sign can put its lowest line under 48 inches while its highest is still under 60, and fail on the first. Elevator car controls are excepted. It is the one rule here that a single tape measurement cannot confirm.

Where these figures come from

Every dimension and rule on this page is from the 2010 ADA Standards for Accessible Design, published by the United States Department of Justice, checked against the standard's own text on every build of this site. These are the federal 2010 ADA Standards. A given project may also be under a state or local code with its own requirements — California's Title 24 is the usual example — and where they differ the stricter one generally governs. Check the standard itself before specifying a sign; every clause quoted here is linked to its source.