If you're a Designer The pooja room is the first room the client's parents will evaluate. If the direction is wrong, the rest of the design does not matter. Build it into your layout before anything else.
If you're a Homeowner If your builder's floor plan has the pooja room in the south or under the staircase, this guide tells you what your alternatives are.
If you're an Architect Pooja room orientation is fixed at the structural stage, along with plumbing lines for any adjoining bathroom. Confirm the northeast zone is clear of shared walls before the floor plan is locked, not after.
Idol facing and praying direction Idols should face west or east. The person praying should face east or north. Pooja platform at chest height. Deities should never be on the floor. Two-shutter wooden door for the entrance. Lamp or diya in the southeast corner of the room.
Critical avoidances No shared wall with any toilet or bathroom on any floor. No bedroom should double as a pooja room. No broken idols or unused items stored in the prayer space. The pooja room should not face south.