1×20 container as an annex: 14.8 m²

Annex in a 20 ft container. Garden office, guest studio or rural holiday let. Not a permanent home: 14.8 m² built.

Make-up1 × 20 ft

Built area14.8 m²

Usable area12.6 m²

UseAnnex

Estimated cost€26,311 to €35,597

Plan to scale, dimensions in metres. Indicative drawing, not a project.

At the ayuntamiento Annex, not a dwelling

Spain has no single minimum area. For the communities not shown here we have not confirmed the minimum in the regulations: ask your ayuntamiento. Check with an architect before you choose a plan.

How much it costs

Between €26,311 and €35,597, VAT included and a ±15% margin. Balanced finish, one-trip containers, urban plot with water, power and sewage. The land is not included.

Container prices from Spanish depots (2025–2026) and building work with a Spain factor on the Contentar engine, checked in November 2026. IVA (VAT) at 21%. Canarias, Ceuta and Melilla are not covered.

Baseline: one container, window and door openings only.

Build complexity: simple.

For and against

For

The cheapest and quickest: a single module, no structural cuts beyond the openings.
Travels whole on a normal lorry and fits tight plots.
An honest plan: bathroom, kitchenette and living/sleeping with no corridors.

Against

14.8 m² built: far below any minimum for a dwelling. It only works as an annex, office or tourist accommodation (confirm with the ayuntamiento).
In a standard 20 ft the finished ceiling height ends up at ~2.25 m; better a 20 ft High Cube.

Sun orientation

Long south façade with a glazed door and a 60–80 cm overhang; west end almost blank.

Adjust the finish, used or new container and the land, and see the cost line by line.

Work out my cost See the Contentar guide · €19

See this plan in 3D on Contentar

1×20 container as an annex: 14.8 m²

How much it costs

For and against

For

Against

Sun orientation

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