Treat the layout as connected zones
A kitchen, dining area and living space may share air but experience different heat gains. Ovens, people and large doors can create concentrated demand at particular times.
The survey should identify the areas that matter most and whether partitions or hallways allow conditioned air to escape into the wider property.
Air distribution affects the result
One powerful unit is not automatically better than two appropriately placed units. Long or L-shaped rooms can have dead areas where air does not circulate effectively.
Unit positions should respect seating and dining areas so normal operation does not create an unwanted draught. Separate controls may be helpful where sections are used at different times.
Balance appearance and practicality
Open-plan rooms often have carefully considered interiors. Pipe routes, indoor-unit style, outdoor position and condensate drainage should be planned before equipment is chosen.
A written proposal can compare options and explain why the recommended arrangement suits the layout, rather than presenting capacity alone.