Roof spaces create distinct heat loads
Roof orientation, insulation, roof windows and reduced ceiling voids can make a loft room gain heat faster than rooms below. The assessment should also account for whether it is a bedroom, office or open-plan suite.
Capacity should be based on the actual construction and use. Simply matching a unit to the floor area can overlook sloping ceilings, solar gain and adjoining spaces.
Find the right indoor position
Low eaves and sloping walls may limit conventional high-wall positions. Air needs a clear path through the occupied part of the room without blowing directly across a bed or desk.
Indoor appearance, sound and future filter access matter. Where a wall-mounted unit is unsuitable, alternative equipment types can be considered if the property and budget support them.
Resolve the route before work begins
Pipework and drainage may need to travel farther than on a ground-floor installation. The survey should identify a route that is serviceable and avoids unnecessary disruption through finished rooms.
Outdoor-unit location, access equipment and electrical supply can affect the quotation. These points should be confirmed rather than treated as assumptions after installation starts.