Vastu Shashtra indicates us the rectangular plot is the most suitable, Square plot is medium suitable and other plots are general for house. To remove Vastu defect of decrease in width in South West plot is given below ;
1) You should measure the Southern side of plot is East to West direction. For example if it is 30 feet than you measure the Northern side of plot East to West only 30 feet. Extra should be left for other purpose.
2) The main entrance, pooja room , kitchen, bedroom, toilet, bathroom, guest room, hall,study room and store room should be build on proper place.
3) Balcony should be North and East direction.