Outdoor Tortoise Pen Construction: Complete Build Guide

An outdoor tortoise pen is the single best housing upgrade you can make for any Mediterranean species — closer to natural conditions, varied grazing, real UVB, and dramatically lower running costs than an indoor enclosure. Marcus built three pens over the past fifteen years and this is the build guide that synthesises what worked.

The principles transfer across temperate tortoise species — Hermann’s, Greek, Russian, Marginated and even Eastern box turtles share most of the requirements. We’ll flag where setups differ.

Climate match — can your climate support an outdoor tortoise?

Outdoor tortoise pens work in any climate where:

• Summer temperatures regularly reach 20–28 °C ambient.
• You can offer suitable winter accommodation (indoor or insulated shed) for cool months.

This covers most of temperate Europe (including the UK), most of the temperate US, large parts of Australia and South Africa. Year-round outdoor housing without indoor backup works only in genuinely Mediterranean climates — southern Spain, Italy, Greece, southern California, parts of Australia. Everywhere else needs winter housing.

Size and shape

Minimum pen size for a single adult Mediterranean tortoise:

• Russian tortoise: 2×1.5 m (3 m² floor).
• Hermann’s, Greek (medium subspecies): 4×3 m (12 m²).
• Hermann’s (large Eastern subspecies): 5×3 m (15 m²).
• Marginated tortoise: 4×3 m (12 m²).
• Eastern box turtle: 4×3 m (12 m²) with heavy planting.

Larger is always better. Pairs need roughly 1.5× the single-tortoise minimum; groups scale accordingly.

Shape matters less than total area, but a roughly square or long-rectangular footprint with a north-south orientation (so morning sun warms one end and afternoon sun the other) maximises basking opportunities.

Construction sequence

1. Layout and marking

Mark the pen perimeter on the ground. Check the area gets sun for most of the day — minimum 4 hours of direct morning or afternoon sun. Tortoises in deep shade don’t thrive.

2. Excavation for the wall foundation

Dig a 30 cm-deep trench around the entire perimeter. Russian tortoises in particular will dig under any unsecured perimeter.

3. Wall construction

Three options:

• Treated timber palisade (most common in the UK) — 20×100 mm planks, buried to half-depth, screwed to corner posts. Cheap, replaceable, doesn’t store heat the way stone does.
• Concrete block wall — permanent, retains heat (which tortoises bask against), more expensive to build.
• Brick wall — same benefits as concrete block.

Above-ground wall height: 30–40 cm. Higher than this and the pen looks like a prison and tortoises can’t see out (they want to see out). Lower and they’ll climb out — surprising what a determined Russian can scale.

4. Substrate preparation

Strip turf if necessary. The pen substrate depends on the species:

• Mediterranean tortoises (Hermann’s, Greek, Russian): mix of grass, bare earth, and loose soil/sand. Plant low weeds throughout but leave bare-earth patches and a sand pile they can dig in. Russians need a dedicated sandy area for burrowing.
• Marginated, Sulcata: similar but lean drier. Less grass, more bare ground.
• Eastern box turtles: heavily-planted with leaf litter on top. Forest-floor recreation.

5. Plant the pen

Edible plants you can grow that double as forage:

• Dandelion — seed it or let it come naturally.
• Plantain (the weed) — same.
• Clover — in moderation.
• Sow thistle, chickweed, mallow — all welcome.
• Hibiscus shrubs — favourite tortoise food. Plant one or two within the pen.
• Mulberry tree (small/dwarf variety) — tortoises will eat the fallen leaves.
• Rose bushes (unsprayed) — flowers are tortoise food.
• Nasturtium — pretty and edible.
• Marigold (calendula) — flowers as treat food.

Avoid planting:

• Toxic plants — lily of the valley, foxglove, oleander, daffodil bulbs.
• Plants that hold water on leaves (causing wet conditions tortoises don’t like).
• Anything sprayed.

Hides and shelter

Tortoises need multiple hiding spots and at least one weatherproof shelter:

• Wooden tortoise house (the “shelter”): waterproof roof, hay bedding inside, entrance facing south-east. Sized to be cosy but not cramped — tortoise plus 50 % extra space.
• Multiple smaller hides: hollow logs, stone overhangs, dense plant clumps. Tortoises rotate between hides based on weather and time of day.
• Burrow access: Russian tortoises especially want a sandy or loose-soil area where they can dig their own scrapes.

Basking spots

Place 2–3 sun-exposed basking stones around the pen:

• South-facing position.
• Large flat stones or paving slabs that retain morning heat.
• Positioned so the tortoise can move on and off the basking spot as it thermoregulates.

Water access

• Shallow water dish (large saucer or plant tray works) sunk into the substrate so the tortoise can walk into it. Deep enough to half-submerge.
• Refresh every other day in normal conditions, daily in hot weather.
• Don’t place near the basking spot (water heats up fast in summer).

Shade

This is often under-provided in new pens. Tortoises need shade options for the hot part of the day:

• Aim for 30–50 % of the pen shaded by canopy, shrubs, or shade-cloth.
• Eastern box turtles need more (60–70 %); they’re forest-edge animals.
• A single afternoon of full midday sun without shade access can kill a tortoise.

Predator-proofing

Threats vary by region but commonly:

• Foxes, raccoons, badgers: dig under fences and into pens. Mesh roof prevents access. Buried perimeter walls help.
• Birds of prey: can take hatchlings and small adults. Mesh roof handles this.
• Dogs (yours or neighbours’): dig into pens out of curiosity. Mesh roof + securely-fastened gate.
• Rats: attack hatchlings. Mesh roof with fine enough gauge.

For hatchling and juvenile pens, mesh roof is essential. For adult-only pens housing well-protected tortoises (sulcatas, large adult Mediterraneans), perimeter security and a partial mesh-covered “safe area” may suffice.

Winter accommodation

For temperate climates, tortoises either brumate or move indoors:

Option A: brumate in the outdoor shelter (warm/Mediterranean climates)

In southern Spain, southern Italy, parts of the southern US, the outdoor shelter can support natural brumation. Pack the shelter with deep hay, ensure it’s dry, and let the tortoise dig in for winter. Check periodically but otherwise leave alone.

Option B: brumate in a controlled indoor environment (UK and most of Europe/US)

Move the tortoise to a fridge box at 4–8 °C for 12–14 weeks. See our brumation guide for the protocol.

Option C: keep warm year-round (some keepers)

Indoor heated enclosure through winter. More work, more expense, but avoids brumation risks.

Maintenance

• Weekly: refill water dish, check perimeter for damage, check planted forage hasn’t been over-grazed.
• Monthly: turn over substrate where tortoise has been digging, refresh hide bedding.
• Quarterly: re-seed grass and weeds in patches that have been over-grazed.
• Annually: check timber walls for rot, replace any damaged components.

Common pen-build mistakes

1. Too small. Tortoises in undersized pens become inactive and develop muscle wasting.
2. No shade. Heatstroke kills.
3. Inadequate predator protection. One overnight fox visit is enough.
4. Walls too low/not buried. Escape.
5. Toxic plants in the pen. Check what grows wild before planting.
6. Single hide. Tortoises want choice.
7. Water dish in basking spot. Cooked.
8. Permanent shade only. Tortoise can’t thermoregulate.

Cost estimate

For a 12 m² Hermann’s tortoise pen with timber walls:

• Timber and posts: £200–400.
• Wooden shelter / tortoise house: £100–250 (DIY) or £200–500 (bought).
• Substrate amendment (sand, soil mixers): £50–100.
• Edible plants (starter): £30–80.
• Wire mesh and frame for roof: £100–250.
• Water dishes, basking stones: £30–60.

Total: £500–1,500 for a quality DIY build. Cheaper than the running costs of an equivalent indoor setup over the same area.

Related on Turtle Times

• Hermann’s Tortoise Care — species-specific pen considerations.
• Russian Tortoise Care — particularly digging-secure builds.
• Mediterranean Tortoise Diet — which plants to grow in the pen.
• Outdoor Turtle Pond Construction — aquatic-species equivalent.
• Turtle & Tortoise Care Index — master husbandry hub.

— Marcus, Turtle Times. Building a pen and want feedback on plans? Contact form — flag “tortoise pen” in the subject.