Does a door frame needs architrave both inside and outside?

This is difficult to answer without seeing it. If the opening has a complete plaster finish then architraves are not required. What you need are 'stops' (the part a hinged door closes against).

No there is no requirement to fit an arc on the frame as long as this sits flush, it is completely aesthetic and would not reduce the gap as sits flush to the frame. If the door frame dose not sit into a rebated frame it should have a stop bead which would reduce this issue. I also feel this would fail fire regs. I would contact your builder as the stopper should of been fitted.

Usually yes though a sliding door frame is different and should be made to suit the purpose or a standard frame adapted Making good and tidying up between frame and wall if needed will depend on circumstances. Sometimes quadrant is used to tidy up frame to wall You may have to fit door stops to the frame to hide his exesive gaps. Sould be a grove routerd under the door and a small block fitted to the floor to stop it swinging out other way is unsightly that is to screw a small block in front of the door Also sound like the door he has fitted is too small! It's a bathroom there are no fire door requirements ((:

Yes I would seek all architraves be applied inside and outside of your bathroom. These do not cost much and do not take long to apply approx 5 minutes per side. I suggest recommending it to the tradesman who installed it this is very straight foward.

As a normal part of a frame build up I would expect to allow for architrave to both side of a standard door frame with a hanging door on it. If this was a supply and fix job and not labour only ? Sliding doors are different in design so require different finishing depending on which type you build. Pocket sliding door Surface sliding door. 1st Please check you quote . Have it explained to you on the process of what was requested by you to cost for bearing in mind as a professional builder should fill in the blank areas of any schedule provided to cost for in a tender. So at least highlight to you within his build up of his costs that he : 1. You never requested Architrave to finish the opening Close of the expose finish between wall and frame. So none was allowed for. But I highlighted the item and provided a cost for it as a separate item for you to decided? You may have provide a schedule for each contractor to tender on to achieve the cheapest cost for the works. 2. Is the sliding door a pocket door or face fix so slides across face of wall? In this case architrave can only be fixed 1 side unless door track is packed off wall to accommodate depth of architrave with extended closing jamb for door lock & stop against. Pocket doors depend on design of pocket? Contemporary or period? Either way you'd always close off the wall too the frame. You just need to find out your builders reason for not doing so and whether you both think it's a reasonable reason or not. Hope this helps.

Architrave is purely aesthetic. If you’re looking for simple clean lines you can either have the frame lie flush with the wall or install a subtle square edge timber fascia.