You will need to measure your room at the widest point taking into account any bay windows and door entrances as below. Once you have these measurements you need to add 10cm on all sides to allow for cutting in during your installation.
When you have the room width you need to check that it is less than the width of the Vinyl you are buying to avoid any joins, for instance if your room width is 4.4m wide and the Vinyl you are buying is available in 4m and 5m widths then you can buy the 5m wide product. If the Vinyl is only 4m wide then you will need to buy either the length of the room by the width twice and use the second piece as a filler to give you your 4.4m width or if you are fitting another room you may find that you have excess from this room that can be utilised as the filler.
Seams should never fall perpendicular to doorways – not in main thoroughfares.
Seams should run toward primary light sources where possible and be kept to a minimum where possible.
Seams should always be kept to a minimum and avoided where possible
Always begin measurements in the centre of doorways rather than the bottom of walls.
You should allow extra in your purchase for patterned goods to allow for pattern matching.