Lighting and ventilation

Key Elements

Adequate ventilation and lighting, including access to daylight, are among the basic elements required to ensure the health and well-being of detainees. The windows must be large enough to enable detainees to read or work in natural light; they must allow the entry of fresh air, and adequate ventilation is required at all times. Windows fitted with bars or other security devices should not block the entry of a sufficient amount of air and light.

Quality air and adequate light contribute to the prevention of certain diseases, such as tuberculosis, and also get rid of carbon dioxide and bad odours. Such conditions contribute to respect for the dignity of detainees.

Detainees placed in solitary confinement and/or under a disciplinary regime should benefit from the same ventilation and lighting conditions as other detainees.

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Adequate ventilation and temperature

Proper ventilation allows detainees to breathe normally, evacuates humidity from their cells and gets rid of bad odours. It is important that inmates are able to open the windows. In hot climates, ventilation can be greatly improved with air conditioning or the installation of electric fans. If, on the other hand, the cells or dormitories are too cold and are poorly insulated, detainees may have to block the windows, thereby preventing the entry of fresh air and natural light. Windows should not be fitted with totally opaque glass so that the prisoners are able to see outside from their cells/dormitories. Similarly, windows should not be placed high up above eye level.

Ventilation must be adequate both in detainees’ living quarters and in all places where they spend time, such as in the workshops or the canteen. Proper kitchen ventilation is particularly important to ensure the hygiene of served meals and food preservation. The prison infirmary should benefit from the same conditions to ensure hygiene standards and to protect medical supplies. The showers must be well ventilated to allow the evacuation of moisture and prevent the transmission of certain diseases, especially skin disorders. Adequate ventilation helps reduce the risk of the transmission of tuberculosis.

The climate is obviously a crucial factor in the management of the ventilation system. The authorities should do everything necessary to ensure both a medium temperature and good air circulation inside the prison. Poor ventilation, combined with a hot and humid climate and overcrowding, is damaging to the health of detainees.

It is also important that spaces reserved for people coming from outside, such as meeting areas for family and lawyer visits, are well ventilated and have sufficient light. Areas allocated for staff, checkpoints, locker rooms and offices should benefit from similar conditions.

Good ventilation can be assured through the inflow of fresh air or through air conditioning, or through a combination thereof. Access to outside air should always be possible. According to the ICRC, a practical way of calculating ventilation in places of detention is to determine the ratio of the size of windows or other openings to the area of the floor. To renew the air in a satisfactory manner, the following two requirements must be fulfilled:

• the size of the openings must be no less than one tenth of the floor area;
• available air space must be no less than 3.5 m3 per person.

Compliance with these requirements is especially important if the detainees are not able to spend long periods in the open air every day. At a minimum, detainees should be able to spend at least one hour a day in the fresh air outdoors.

Even when there are enough windows, air can be in short supply if the openings are blocked by too many, or inappropriate, security fixtures such as shutters, bars or metal plates. It is the responsibility of the authorities to find the right balance between preventing the risk of escape and ensuring that air circulation is sufficient for the well-being of the detainees.


Adequate lighting is required to maintain the physical and mental health of detainees and prison staff. The lack of natural light over a prolonged period can permanently affect the mental health of detainees. Spending time outside the cell, especially in the open air exercise yard, gives detainees immediate access to daylight. Without being forced to do so, detainees should be authorised to go outdoors for at least one hour daily.

The design and size of the windows should enable detainees to read or work with natural light during daytime. As with ventilation, security measures should not block the windows to the point of not letting in sufficient daylight. In addition to natural light, detainees should have access to lamps in their cells to allow them to read or work without damaging their eyesight. Lighting in the workshops should also be adequate to preserve the eyesight of detainees and prevent accidents.

Sufficient amounts of both natural and artificial light should be available for the lighting of common areas such as exercise yards, shower rooms, the canteen and corridors. Poorly lit areas are conducive to the outbreak of fights, violence and abuse against vulnerable detainees.

Lighting management must take into account the needs of detainees, who should be able to read in their cells after nightfall. In dormitories and cells with several occupants, individual lighting should be adjustable so as to enable detainees to read without disturbing fellow inmates. Detainees should be able to control lighting at night, under the supervision of prison guards. Other than in exceptional circumstances, lights should not be left on all night.

Solitary confinement and disciplinary measures

Temporary cells for prisoners subjected to disciplinary action and/or placed in solitary confinement must meet the same criteria to ensure good ventilation and lighting. Deprivation or restriction of properly ventilated air or access to light should be prohibited and should not constitute a form of punishment. Detainees placed in these cells must be able to read in natural light and have access to a reading lamp at nightfall. Such cells are sometimes located in a basement or mezzanine, and consequently have limited or no access to natural light and ventilation, and a high level of humidity. Whatever the solutions found by the authorities, they should ensure that these cells are not in worse condition than other cells.

Placement in solitary confinement for security reasons requires careful monitoring of the individual concerned by the authorities and health personnel. For this reason, it may be necessary to keep the solitary confinement cell dimly lit at night. This measure should not prevent the detainee concerned from sleeping and should not be extended for long periods. Artificial lighting around the clock must be avoided.

It is particularly important to ensure optimum ventilation and lighting for the elderly and sick, especially for detainees suffering from tuberculosis, including the multi-drug-resistant form of the disease. Good ventilation conditions and natural light not only contribute to their healing, but also help reduce the risk of contagion. Poor ventilation is one of the main factors, along with late diagnosis, overcrowding and inadequate treatment, that favour the transmission of tuberculosis.


Detainees with physical disabilities should have the same access to natural light and fresh air as their fellow inmates. If necessary, the authorities should make reasonable arrangements to ensure such access.


It is especially important that pregnant women and mothers who are nursing and/or who have young children are placed in well-ventilated areas with sufficient natural light. At night, artificial lighting should not disturb their sleep. Particular attention should be paid by the authorities to ensure a medium temperature in their cells or dormitories at all times.

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Questions for monitors

What are the cell window sizes? Can they be opened by the detainees? Are they blocked by security devices?

What is the general quality of the air and the level of humidity? What is the ambient temperature?

Can the detainees regulate the ventilation themselves?

What heating system is in place? Is it suitable for the climate?

Do the detainees have control of the light switches? Are there areas where the lighting remains switched on all night?

Is there enough natural light to enable detainees to read and work without damaging their eyesight?

What is the condition of the ventilation system and the quality of lighting in the kitchens and in the infirmary?

Are there poorly lit or poorly ventilated areas within the facility?

What is the state of the lighting and ventilation in the disciplinary and solitary confinement cells?

Do the detainees have access to the exercise yard? If so, how often and for how long?

Do any of the detainees have tuberculosis? What measures are being taken if this is the case?


What are the housing conditions of pregnant detainees and detainees who are nursing and/or who have young children with them? Do they have sufficient access to fresh air and natural light?

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