Tortoises will thrive best in an environment where they have both indoor and outdoor access. A tortoise requires much more room than most reptiles and proper housing is vital to ensure that your tortoise is happy. If you are unable to provide adequate space then owning a tortoise should be reconsidered.
Outdoor space for tortoises
Ideally, tortoises should have access to a well-drained area of your garden with sections that are both in shade and full sunlight. You should aim to provide your tortoise with a variety of facilities including a grassed area, plants for shade, rocks, open areas in direct sunlight for basking, and a selection of edible vegetation. Having some sloped areas within the enclosure will aid basking and thermoregulation, while rocks will help your tortoise right himself if he becomes cast (stuck on his back). Getting cast can be dangerous for a tortoise, they find it very stressful and in some cases it can result in death from overheating. Your tortoise's living space should be well-drained to prevent shell and breathing infections.
It is important that the enclosure is well-built to stop predators getting in and your tortoise getting out (they are surprisingly agile). It will need solid sides as tortoises will spend hours attempting an escape when they can see beyond the perimeter. Burying wire below the floor of the enclosure will also help if your tortoise likes to dig. Secure a wire mesh over the top to prevent overhead attacks.
You can create a ‘tortoise conservatory’ in the enclosure - use a strong, rot-proof wooden frame and cover it with polycarbonate transparent roofing to create an area within the enclosure that could reach up to 10°C warmer - your tortoise will be able to use this as part of his thermoregulation cycle. He must be able to come and go from this area when he chooses.
Indoor space for a tortoise
A garden shed with an electricity supply makes an ideal indoor enclosure for a tortoise - ideally he should be able to access both his indoor and outdoor area when he chooses (a low cat flap can make this possible). The indoor area should have a hide box if your tortoise feels the need to hide away. The ideal substrate is a mix of 50/50 soft play sand to top soil. It will need to be at least 5cm deep for small tortoises and 7.5cm deep for larger tortoises to allow them to dig and bury themselves if they wish. A tiled area for feeding is both useful and hygienic.
Heat sources for tortoises
Tortoises need access to both basking and UVB light. A basking lamp should be on for around 12 hours during the day in your tortoise's indoor area, set to around 25°C. Ensure that all cables and flexes are secure and out of reach, and check them regularly for any damage or wear. Suspend the light from the roof of the enclosure, ensuring that your tortoise cannot make direct contact with it. Place rocks in the vicinity to aid his correction back to the right way up if he casts.
Apart from occasions where the room temperature falls below 15°C, your tortoise will not need additional heating during the night. What is important, though, is that your tortoise is dry. On occasions where the temperature is likely to fall below 15°C, an overhead infra-red ceramic dull emitter heater in a heat-proof holder is recommended. This will emit a radiant heat but no light. Underfloor heating mats are not recommended - tortoises require a radiant source of heat and light for thermoregulation to take place.
Do tortoises need UV light?
A tortoise needs UVB light in order for his body to metabolise calcium. Without adequate calcium he will not be able to develop properly, leading to weak bones and a poor-quality shell. Your tortoise should have access to 12 hours of UVB light per day to mimic the daylight hours in the wild. The best source of UVB is the sun, and access to an outdoor enclosure in the summer is the best way to ensure your tortoise gets enough UVB exposure. UVB cannot travel through glass, so placing him in a bright room inside will not work.
When your tortoise is inside he will need a good-quality UVB light for 12 hours a day. Research the different types of UVB lights on the market and make sure that you purchase one that will provide an adequate output of UVB for your tortoise. The light will need to be checked regularly and the bulbs changed as recommended by the manufacturer to ensure sufficient levels are provided.