Hello people who understand property plans. Here is a plan of my property, or rather an extract. You’ll see there is an external staircase – the staircase leads up to my front door. Now the steel joists underneath that staircase are perishing and require replacement. At first I assume that as this was part of the structure of the main building then all the leaseholders would be liable to pay but my fellow leaseholder has a different interpretation. I’m okay to interpret the wording of the lease but I don’t understand how the plan works – what is that diagonal line going across the staircase? Is the fact that the thick black line isn’t there after the staircase and indication that there is no wall/barrier?