Performance wise -
EASA CAT.POL.A.210
Track changes shall not be allowed up to the point at which the net take-off flight path has achieved a height equal to one half the wingspan but not less than 50 ft above the elevation of the end of the TORA. Thereafter, up to a height of 400 ft it is assumed that the aeroplane is banked by no more than 15°. Above 400 ft height bank angles greater than 15°, but not more than 25° may be scheduled.
Design wise -
PANS-OPS 8168 I-3-2-2
When a departure route requires a turn of more than 15°, it is called a turning departure. Straight flight is assumed until reaching an altitude/height of at least 120 m (394 ft), or 90 m (295 ft) for helicopters. Procedures normally cater for turns at a point 600 m from the beginning of the runway. However, in some cases turns may not be initiated before the DER (or a specified point), and this information will be noted on the departure chart.
No provision is made in this document for turning departures requiring a turn below 120 m (394 ft) (90 m (295 ft) for helicopters) above the elevation of the DER.