Police were called at 2.39pm on Friday, January 25, to reports of a theft from a van in Mountway Close.
Between 2.30pm and 2.35pm, the silver Ford Transit was broken into and tools were stolen.
The victim, a man in his 30s, returned to his van - which had been left locked and secured - to find the side door open and items missing.
Among the items stolen were a DeWalt electric drill, two nail guns, a DeWalt cutter, a DeWalt router, compressor, spirit level, DeWalt sander, chisel, DeWalt batteries, black and yellow Makita carpentry tools, along with eight DeWalt carpentry tools.
The victim is still compiling a list of other stolen items.
•Any witnesses or anyone with information is asked to contact Hertfordshire Constabulary on the non-emergency number 101, quoting reference 41/8142/19.