Hi Master Cecil, Thank you for your quick reply. Yes I do realise that the space is really limited and it is challenging to think of an ideal way to optimise the placement of the altar. With reference to the suggested option 3, there is a little hole beside the area in the balcony. It actually represents a water pipe, probably for draining water in the balcony area. With this info, does it mean that option 3 is still feasible? A follow-up question: Could the altar be placed in the balcony?