As far as the mechanical work goes thats all on him. he will be piping everything to code (hopefully). if he asks you what type of material you would like to use on this project copper is best for water lines as for one copper joints are stronger than plastic and two copper is natural so your not drinking something that was sitting in plastic for god knows how long. now a days the go to is pex which is fine and also cheaper.

Most of the Keurig coffees taste very similar, which isn't very good, and I hate the cost and waste of plastic.

Remember to use a plastic chair protector for your office chairs as the casters WILL dent the floor...pads under the legs of chairs/furniture...If you were thinking of turning it into rental down the road, I'd go laminate in a heartbeat. 

They sell a little install kit that has a plastic block used to snap them together and a metal bar that you use for the pieces next to the wall.

Original hardwood floors  over modern plastic looking wood floors anyday. 

At that time there were no escrow services so I had to pull 72k out of the bank, put it in a plastic shopping bag and hike it over to the title office for the transaction.

@Sam Dal,Can you take some drinking straws or some other plastic tubing and use that to extend the dispenser and fill the hole with some kind of expanding foam barrier?

Rather than using ABS (plastic) for the drains he installs cast-iron that has a life expectancy for commercial purposes for 15 years.A city inspector catches the Hispanics working on the job and the city stops the work.

I now provide pre-cut thick plastic washable shelf liners and actually have a clause in my lease about damage to cabinets -- no nails, push pins, other sharp objects (I've had tenants hang pictures with pushpins on side kitchen cabinets, screwed in hooks to hang things) and that stains and damage to cabinetry will not be considered normal wear and tear.   

I would fill in with the solid plastic Restoration or similar, a can of non expand window and door spray foam and whatever it took for good looking trimA perfect DIY project for an hour or three.