Assuming this has nothing to do with his/her business then it has no tax effect.  I would however hold onto the receipts for possible basis addition when they sell the home.

If they're in some sort of business that needs these items then some are depreciable and some are deductible.

Direct repairs to the home office are okay. Indirect may or may not be.  Repairs to the entire home such as fixing the walkway, a roof, etc. may work.  Fixing the kid's bathroom sink, nope.

"taxpayer has added expenses"

Do you know how to differentiate Expense, and expenditure that is for assets (equipment and improvement)?

Is the thermospatub for their physical therapy or chiropractic practice? Or, a plating shop and that is the gold plating bath? How is that business? If not, it's personal.

The same for the masonry: an improvement for business purposes such as furnace or kiln?

The HVAC might qualify for energy efficiency credit.

Having a home office doesn't turn everything into business. Paying for things out of a business bank account doesn't turn everything into business. Your clients will not understand this, but you need to understand this.

Is this ordinary and necessary equipment for the business?

Heating and AC would be depreciated as a Home Office Improvement.

As for the other items ...

Is the Thermo Spa Tub used directly for his business, such as for treating clients?

Are all of the other items part of the installation and use of the Thermo Spa Tub?  If not, what exactly were the other items for?