Guard and watch tower

What the system calculates

You choose the structure (steel or timber), platform height, cabin, walkway around it, stairs or ladder, railing, floodlights and cameras. The system calculates:

- pad footings, legs and cross bracing every 3 m of height;

- platform beams, joists and decking;

- stair flights with landings or a ladder;

- railing with balusters at the chosen spacing;

- the cabin frame, cladding, insulation, windows, door and mono-pitch roof;

- floodlights, cameras and a video recorder.

Hunting tower

A simpler option is a timber platform with a small roof on four posts and a ladder. A ladder above 3 m is awkward and risky, so the system suggests stairs or a caged ladder.

Tall tower

For a taller tower the stairs are split into flights of up to 3 m with landings. From 6 m the legs, bracing, footings and wind load must be designed by a structural engineer — the system shows quantities, not member sizes.

Permits and neighbours

- A technical observation tower is an engineering structure (STR 1.01.03 Annex 3 row 4.5). Up to 15 m its group depends on K = S × H³: group I up to 10,000, group II up to 40,000.

- Above 15 m it is a non-special structure and always needs a permit. A roofed one of 20 m or more is a special structure.

- If the cabin is most of the structure, the tower may count as a building: group I up to 5 m and 50 m², group II up to 8.5 m and 80 m². The category is unclear, so the system shows both.

- Closer than 1 m to the boundary — the neighbour's consent. A roofed tower 1–3 m from the boundary needs consent if it is taller than the distance.

Railings

Building rules require a guard from 1.5 m, railings at least 0.9 m high and gaps between balusters of at most 120 mm. From 2027 external stairs and landings need at least 1.2 m. For a tower these apply by analogy, so the default railing is 1.2 m.