I just figured it out: This person is from India (hence no bathtubs - these are wetrooms w/ shower only and a floor drain) and since this is a corner lot hemmed in by neighboring houses, OTS = Open To Sky... ...and that massive staircase probably goes up to the roof where they have their only outdoor space as well as space for hanging laundry, etc. IMO, putting the car on the exposed corner is the worst use of space and light - I'd stash the car on another side against the neighbor's house where there's no light - locating the public rooms and the kitchen along the front of the house and the bedrooms in the back where they don't necessarily need daylight - perhaps through the use of clerestory windows into the public rooms, the light can be borrowed for the center bedroom... Either way, Inkwitch is right (if a bit abrupt) I'd get a new architect who has some talent for efficient small space design to do your home.

Pankaj, I just realized that initially you told us that the bathroom area was 12'-0" x 9'-0" and later you mentioned that it was 11'-8" x 8'-0". In the last floor plan, I forgot to change the bathroom with the new dimensions. Below is the floor plan with the correct dimensions for the bathroom. The bedroom is ok, I drew it 19'-2" x 12'-6". The new layout does not change the way things are placed. Everything still fit. The only difference is that the vanity is now 4'-4" long instead of 4'-8". and the toilet is closer to the shower by 1'-0". Can you give me the lengths of the walls K and L. They are the walls between the vanity and the shower area. I will send you the new layout once you give me the length of these 2 walls.

Based on the dimensions you have given and the religious aspects you mention you are very restricted in what the layout can be. The best solution I see means you have to move the door towards the south by 36". I suggest you make it a pocket door retracting towards the south wall. This leaves 36" x 60" of space on the north wall for either a shower or tub. The vanity would be on the west wall ( across from the door) spaced away from the tub or shower around 12". Make sure the vanity cabinet is shallow, no more than 21" deep. The vanity should be able to be about 48" wide. The toilet will go on the South wall with the right side of it close to the East wall. Code calls for approx. 33" of width for the toilet overall. If budget allows you could continue the vanity cabinets into the corner of the south wall however keep in mind that most of that area that will be next to the toilet and not easily accessible. But it would provide extra storage or counter space. The sink will have to be centered in the 48" part of the vanity. You could also frame out the southwest corner to capture the side of the vanity instead of a longer vanity. Hope this helps.

I agree with divadeva. More lights. If you can add pot lights do it. If they're already there add task lighting and up the wattage on the bulbs on the pot lights (replace with LED and you can make them brighter because the wattage on LED is lower for brighter light). If you have all of that add decorative lighting. If ventilation is an issue find a way to move the air around or add air filtration. Maybe the HVAC is deficient. Maybe you can add a HEPA filter instead of the standard one that comes with the unit. Call an HVAC specialist to see if there is a way to boost air flow in the room.