My guess would be in the existing room you have something blocking where the doorway would go. Try moving things out of that space and seeing if the room fits again. From the sounds of it you know that it looks like it is supposed to fit, which fits this reasoning...
Shrug.
Base building is very fickle, even if you move stuff out of the way, sometimes the room does not want be put there at all!
Sometimes, it requires moving far more round than you planned.
Trial & error, i'm afraid!
"Like War_Hero said, leave it as it is, it toughens up the softies." - Naz Nomad
Union Heroes
War Borg - Leader of The Paragon Knights
Union Villains
McCabe - Co-leader of The Rogue Knights
Defiant - Supreme Hero
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I am trying to add rooms to my base, although i have both the room and the prestigue to add a new room the option remains red on the grid altenating between 'room must not overlap' to 'room must be connected by.......etc'.
There is one grid spare between rooms and you can see the doorway automatically generated yet the option remains red?, any ideas?, i have searched on forums and websites to no avail 
Any help appreciated
x
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Check out if the some sort of item blocks the connecting corridor (game places corridors automatically and we can't really affect it). After the room is in place there MUST be at least one corridor connecting the room to rest of base. It is easy to miss such items as they dont need to be exactly at the wall even for this to happen. Remove some items from the room youre trying to connect to (near the corridor exit) and try again. Once the new room is in place, you can move the corridor and replace the items you temporarily deleted/moved. lowering floors and raising roofs in the room youre connecting to may also help .
Thats all I can think of really, if the plot is of right size and all.
Normally I get this problem because I use wall mounted lighting in my base and it means the wall can't be deleted to place the doorway.
Also, don't forget that unless you've reached the "ring stage" of base building, you can't change where the door goes (once you have the rooms in a ring, you can move the doors around as it'll still leave one door intact)
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Normally I get this problem because I use wall mounted lighting in my base and it means the wall can't be deleted to place the doorway.
Also, don't forget that unless you've reached the "ring stage" of base building, you can't change where the door goes (once you have the rooms in a ring, you can move the doors around as it'll still leave one door intact)
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You can always move corridors between existing rooms (unless blocked by items) even if theres just one corridor, its just that you cant do anything about corridor placement WHILE placing NEW rooms..
If this sounds weird, try buying a new corridor next to existing one without deleting the old one.. Youll understand what i mean.
yea, prolly the case.. decorations usually mess up room placement/movement. and in some cases the default doorway cant be done, and the editor refuses to choose an alternative. this will become even more complex when moving rooms.
i usually (if i can) remove all rooms not containing slavage-build equipment, and re build the base from that stage.. a pain when it comes to constant redecorate, but will also remove alot of the hassle with room-placements.
if ur located on Union:
May i suggest in the future to send me or @ max powerz an in-game tell, and we will invite u to 'Union Leaders'. a global channel for basebuilders and SG-leaders. This will enable u to get instant advice and solutions live in-game from some of the most experienced base-builders on Union 
Also check floor levels - I find links are a bit tough to make if your two adjoining rooms are not at the same level where they are to be joined.
I am trying to add rooms to my base, although i have both the room and the prestigue to add a new room the option remains red on the grid altenating between 'room must not overlap' to 'room must be connected by.......etc'.
There is one grid spare between rooms and you can see the doorway automatically generated yet the option remains red?, any ideas?, i have searched on forums and websites to no avail
Any help appreciated
x