One quote assumes a shared wall is available.
THE PORTSMOUTH FIELD GUIDE / AIR CONDITIONING
Air conditioning installers in Portsmouth
A flat's shared wall may need approval before an outdoor unit is fitted. Settle the Portsmouth consent and pipe route before booking cooling work.

START WITH THE PROPERTY
Get shared-building consent into the brief
For a Portsmouth flat, identify who can approve equipment on an external wall or shared roof and whether pipework may pass through communal space. Send those rules with your room details.
BEFORE YOU ACCEPT A QUOTE
Check the installation path end to end
A quote should state the permitted outdoor position, indoor unit locations, condensate disposal and visible finishes. If consent is pending, make the price conditional instead of assuming it will be granted.
ILLUSTRATIVE QUOTE COMPARISON
Who may approve a unit on a flat's exterior?
Another lists managing-agent consent and an alternative route if it is refused.
Obtain the building rules before booking installation. If the route changes, ask for new noise, drainage and price details.
ANOTHER PROJECT AT THE SAME ADDRESS?
Explore the other options in Portsmouth.
NEXT STEP IN PORTSMOUTH
Size the rooms once consent is plausible.
A permitted outdoor location does not settle the cooling design. Give glazing and occupancy details for each room so the proposed indoor capacities are justified.