9 Surface of Courts and Playing Conditions
(a) Surface
The surface of the courts to be used in the Competition shall be grass turf; a natural or artificial fine gritty material; cement; or a bituminous composition or a synthetic surface; but in no case shall a Tie be played on a surface of stone or any other surface except by mutual agreement between the two Nations competing. If the Host Nation under normal conditions as determined by the Referee is unable to provide a playable match court at the scheduled starting time, the Home Nation shall forfeit the Tie and the Visiting Nation shall be determined the winner of the Tie. The Referee may extend the starting time if, in his opinion, the match court could satisfactorily be made playable within a reasonable time which shall not exceed three hours. For all Ties in the World Group and Group I the court surface must be of a type used in a Grand Slam Tournament or in a minimum of three tournaments in the Men’s Professional Tour held in the year previous to the Tie.
Note: For the purpose of this regulation ’NORMAL CONDITIONS’ refers to a situation when, for example, the weather and climate conditions are good and satisfactory for play but the match court, due to negligence by the Home Nation and/or court manufacturer, still fails to be playable in the opinion of the Referee. Rain or other unavoidable hindrance beyond the control of anyone would not constitute a reason for the Referee to call off a Tie and award the victory to the Visiting Nation.
(b) Artificial Lighting
Play is allowed with artificial lighting in the open air after sunset or on covered courts provided there is a minimum of 500 lux per square metre (1,200 lux in the case of the World Group), evenly distributed over the court surface, and practice facilities for both teams with similar lighting are available. All measurements are to be taken one metre above the playing surface.
(c) General Conditions for the Tie
The Davis Cup Committee may, at any time, at its discretion intervene if, in its opinion, the conditions for or the circumstances surrounding any Tie, including but without limitation to, the climate, court surface or local organisation do not or are unlikely to ensure the maintenance at all times of the high ideals of the competition.