Starting layout: 4m × 3m. This is an illustrative design prompt; check furniture, equipment and internal clearances.
Start with the layout
Draw the equipment at its real dimensions, including moving parts, access and exercise clearance.
Get the specification right
Ask the structural designer to check concentrated and dynamic loads from racks, weights and machines. Rubber flooring does not solve an inadequate structure.
Plan the details early
Check finished ceiling height for overhead movements, then plan ventilation, temperature control and neighbour-friendly noise management.
Build a complete brief
Record internal dimensions, intended use, ventilation, services and access. Share the same brief with every supplier so quotes can be compared. Check planning and building-control requirements before committing to a particular height or footprint.