Ditto to Eric's comments about graph paper and laptops. I'd be afraid of dropping the laptop. I also work on older industrial buildings.
I always take my Bosch Laser measurer, my Wedge Smartlevel for measuring roof slopes and uneven floors, a stud/joist finder, and my digital camera. I also take a folding rule, 30 foot tape, and appropriate batteries for backup. I carry all this in a compact rugged tool kit with lots of pockets and a shoulder strap.
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Edward Acker AIA
Senior Architect
Winchester VA
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