Condensation problems

[grumpyjohn2]

Hi.
I know this is a much discussed topic but we have problems as you can see with condensation and are at our wits end.
These doors are both relatively recently fitted during an extension build 18months ago.
Condensation build up in cold weather is quite bad and risks damage to flooring and skirting/walls.
Builder...(surprise surprise!! doesn't want to know and has ceased trading but since restarted under new name)
We now know that no cavity closer was fitted underneath but were fitted to sides.
Does anybody have any advice about how we can sort this annoying issue before it gets to damage so much more.
Vents are fitted and used.
Anything else you need to know or more pictures please ask.
We are open to any serious suggestions to help.
Thanks in advance

 

[Sonic70]

My own patio doors get condensation at the bottom in this cold weather. We use a karcher window vac to remove water each morning. It's also been better since we stopped drying clothes on radiators and invested in a heat pump tumble dryer. Also got a meaco dehumidifier we use occasionally as well.

 

[Koolpc]

Ventilation is important as is heating the room sufficiently.