Covered tennis facilities are extremely popular. Covered facilities maximise the use of a tennis court because they can be used during inclement or cold weather.
Indoor tennis tournaments can also guarantee play at designated times, which is not always possible at outdoor events. Some modern indoor tennis centres are now climate controlled so the playing conditions are always comfortable for the player, which cannot be guaranteed with outdoor facilities.
An indoor court is one which is completely covered by a roof, and for which playing conditions are largely artificial.
Note: Artificial playing conditions would include artificial light, protection from rain, and little or no wind. Courts housed under a permanent structure (including ‘air halls’) but without walls may be defined as ‘indoor’ if the playing conditions are still largely artificial and temperature and/or humidity can be manipulated. Covered courts (including courts with retractable roofs) may be defined as ‘outdoor’ – even if artificial lighting is required – if they are exposed to other environmental factors or the roof is open by default.
Types of covered court structure
There are three main types of indoor court structures. All three can be either temporary or permanent structures depending on where they are located and for how much of the year they are needed.
- Air-supported structures
- Fabric frame structures
- Rigid framed buildings
Air structures, more commonly known as ‘bubbles’ are relatively inexpensive and efficient to construct. Air structures usually comprise single- or multi-layered fabric, which are erected and supported using air pressure provided by substantial air blowers, which are also used to ventilate and control the climate within the bubble. The majority of air structures are constructed of woven polyester fabric, which is usually treated with a protective coating. This protective coating is used to block out ultraviolet light and to prolong the life of the fabric. The average life of a modern air structure is between 10 and 12 years. The fabrics used are can be opaque or translucent.
Translucent fabrics permit a large amount of natural light to pass through them, which helps to trap and retain heat in the winter period, but can promote extremely high temperatures in the summer, which need to be controlled. The light usually passes through the fabric in irregular patches; therefore most air structures combat this problem by using interior lighting to create the optimum lighting for playing tennis. Opaque fabrics provide more constant lighting, which reduces the need for extra lighting during the daytime. The fabric also has a much better control of temperature in all seasons.
Air structures still need to comply with building rules and regulations and must maintain safety of the public at all times, e.g. by avoiding the build up of excessive snow loads. Air structures can be erected at certain times of the year (usually autumn and winter) to increase the available court time. Courts should be designed to accommodate an air structure if it is likely one will be needed. An air structure must withstand local climatic conditions.
The main advantages of an air-supported structure are they are relatively inexpensive to purchase and are easy to install. They can be easily maintained. They can be taken down during the summer, allowing play both indoor and outdoor.
Fabric frame structures
Fabric frame structures are particularly useful if courts need to be covered all year round. Fabric frame structures are more expensive to install than air structures, but will offer savings in the long term by virtue of their superior insulation.
Fabric frame structures comprise a steel, aluminium or wood framework, with a fabric similar to the fabric used on air structures, stretched tightly over the framework. An inner lining is often used in places where the climate is variable, to help retain the heat in winter and resist it in the summer months. The structures have sloped walls, as they need to be able to cope with modest snow loads and high winds.
Fabric frame structures are modular and usually cover between one and four courts. However, they can be designed to cover as many courts as necessary.
This type of structure is very effective in extremely hot climates. They provide two major benefits, firstly the keep the intense sun off the court during the daytime and secondly a retractable roof can be used to ventilate the courts as an alternative to an air conditioning system.
Fabric frame structures have a longer lifespan than air structures. The fabric usually lasts for 15-20 years with the framework lasting up to 40 years.
Rigid framed buildings
Steel is the most common material used to construct the frame of an indoor tennis centre. Steel buildings cost more to construct than air- or fabric-supported structures, but will offer better insulation, and therefore providing long term savings on the overall running costs of the building (mainly heating and air conditioning).
If the building is well maintained it can last for up to 65 years.
They can be insulated for efficiency and air-conditioned for summer use.
Environment of covered courts
When designing an indoor tennis facility, the internal environment must be considered, in particular:
- Ceiling system and insulation
- Heating, ventilation and air conditioning system
- Perimeter curtains and divider netting.
The design of an efficient energy source and heating system should be established prior to the commencement of any building. The planning should be undertaken by a specialist engineer.
Effective regulation of both natural and artificial lighting and of the internal environment must be maintained. Mechanical and electrical systems should be suitably concealed without prejudice to their operation and maintenance. They should not interfere with the use of the indoor courts or conflict with the clear height requirements above the courts.
Ceiling system and insulation
Ceiling systems in tennis buildings improve the appearance of covered courts and serve two other important purposes. They offer a highly reflective surface to improve the performance of lighting systems and they provide significant insulation, enhancing the performance of the HVAC system. In addition, they provide a vapour barrier and assist in controlling condensation within the structure.
Heating, ventilation and air conditioning (HVAC)
An effective HVAC system should be capable of changing air within the structure with minimal noise or draft. In winter, the heating system should maintain the building temperature between 13-17°C (55-62°F), whilst in summer, the air conditioning should maintain an indoor temperature of 6-8°C (10-15°F) below the outside temperature with 55-60% humidity. Noise should not exceed 45 dB.
When heating covered courts containing clay courts, consideration must be given to the type of system used, to prevent uneven heating and drying of the surface.
Lighting of covered courts should be uniform and glare-free. All lighting systems should be designed to provide adequate visibility of the ball at all locations whilst in play, for both players and spectators, with minimum glare.
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Tennis requires a high degree of concentration. Noise should be avoided as far as possible. Empty tennis halls should not generate reverberation for longer than 3 seconds at frequencies greater than 500 Hz. Carpeting has a damping effect, as does perimeter and divider netting.
A ceiling design with noise-absorbing elements attached at a distance of 0.15 to 0.20 m from the roof structure is recommended. The hall air must be able to circulate between the noise-absorbent panels and the roof surface since this reduces the sound level in the lower frequency ranges. Sound-absorbent elements made of mineral wool above a suspended boarded ceiling are usually sufficient for effective acoustic damping.
Acoustic improvements should be entrusted to experts in this field.
Perimeter curtains and divider netting
Perimeter curtains provide a background against which to see the ball and keep balls within the court, as well as screening out the distraction of players going to/from adjacent courts. Divider nets are used to separate courts and to contain the balls within the court. They may be mesh or a combination of solid vinyl at the bottom, and mesh at the top. Netting should be hung in two pieces that may be drawn to the ends of the court or to the centre of the court for maintenance.
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The minimum height above the playing area varies according to the use for which the court is intended. For outdoor courts, the space directly above the playing surface should be free from obstructions. For indoor courts, specifications are normally given for the height above the net, baseline and backstop. These are summarised in the table below.
|Height above the net at the...
||9 minimum (12 for World Group)
||9 minimum (12 for World Group)
||9 minimum (12 for World Group)