Guide Specifications for the General Requirements and Conditions Revised 1988
Tennis Court Orientation
From a study of weather and playing conditions in our country it has been determined that, in general, courts built south of the 38th degree parallel, a line which runs approximately through Louisville, Kentucky, are playable on a twelve month year-around basis. Courts north of the 38th degree parallel are considered non-playable for approximately four to five winter months of the year due to cold weather. Therefore, because of the summer sun angle during standard time, at approximately 3 p.m. to 4 p.m., outdoor courts north of the 38th degree parallel can be oriented directly true north-south. This will allow good playing conditions during the summer months from mid to late afternoon.
Outdoor courts built south of the 38th degree parallel, however, are considered generally good for play all year around. By a careful analysis of sun angles at both equinox times in mid-March and mid-September, between 3 p.m. and 4 p.m., when it is assumed that most tennis is played, and taking into account the fact that about 85% of the players are right-handed, it has been determined that the most comfortable angle for court setting is 22° south-east and north-west for the length of the court off true north-south. This can even be increased to 30° off north-south for courts built in the extreme southern areas of the United States.
The first courts known to be oriented 22° south-east and north-west were constructed in Houston about 35 years ago. Observation of these and other courts south of the 38th parallel at both equinox times show no shadow of the net on either side of the court between 3 p.m. and 4 p.m., which indicates that each side of the court has equal sun angles, which is assumed to be the ideal outdoor playing condition with respect to sun glare affecting either side of the court more than the other.
As the sun moves lower (south) in the winter months and higher (north) in the mid-summer months, the sun glare angle will be slightly more on the respective sides of the courts, but not enough to materially produce excessive glare.
On the other hand, if an outdoor court were laid out exactly north-south in the southern part of the United States, the intense glare from the sun in the mid-winter months between 3 p.m. and 4 p.m. would seriously affect right-handed players on the north court by their having to look directly into the suns rays as they face the south court, and would make playing conditions extremely uncomfortable.
The final orientation of the tennis court is also affected by the cost of construction relative to the substantial slope of the land, zoning requirements and/or the owner's wishes. The need to orient a tennis court in a predominant east - west direction may exist in order to fulfill the construction criteria for the tennis facility, but it should be recognized that a predominant east-west orientation may substantially impair the usability of the facility.
If the owner's desires are for evening or night play, orientation does not become an extremely important concern. Refer to the outdoor lighting section for further information.
This court orientation has been officially approved by the United States Tennis Association and the U.S. Tennis Court and Track Builders Association.