The floor plans I have recreated of
the Lancer hacienda are, of course, all guesswork. Throughout
the show many of the rooms on the set were used for more than
one shot or episode. Sometimes a room appeared to be on the
second floor, then in the next episode it was on the ground floor,
across the courtyard. The movement of the rooms and also some
of the furniture and paintings has been described as being
'fluid'.
This is my early version of the ground floor. Bedrooms would be above. Numbers 22 and 23 are ground floor guest rooms off the courtyard that Jelly also used. Numbers 1 and 2 were used as bedrooms ( top of picture). In Lifeline Jelly slept in one of these when he thought he was dying. 
Originally they filmed in the real house, so in the pilot episode you can see the dining room through a door at the end of the great room - but was later turned into a hallway. I later realized that dininng room juts out of the house and is located where I have drawn a vegetable garden. The set's hallway is seen in The Wedding, Glory and of course in CAWH, from where Scott staggered in.
Number 12 is a small room that was never really used, but it led the way to the kitchen. There was an octagonal green leather-covered table in there that might be used for playing cards. In this small picture from The Kid, they pulled it out of the small room, which was perhaps a butler's pantry or card room.
The front foyer was visible in more than one episode, and there was a large piece of art facing you as you entered. When seen from the great room, the foyer has a large painting on the far wall. In The Prodigal, when Murdoch lets the soldiers in the front door, they walk past him to the rear bedroom on the ground floor, so the main hall must go past the main staircase, though it is never seen.
The kitchen had a long farmer's table, a central tiled hearth with a spit (seen in Buscaderos) and an arch-top oven with an iron door typical of those used for baking bread. There is a back stairway just outside the kitchen that leads to the second floor and a wine cellar below.