I telecommute from home at least 4 days a week. Can I deduct light, heat, internet, % of my rent, the desk/chair/shredder/chair mat I bought?

[JulieCo]

It depends.  To take a home office deduction, you must meet the requirements to be eligible:  the office must be used regularly and exclusively for the business, plus it must be for the convenience of the employer and not for your convenience. 

 Also, note that job-related expenses are only deductible if you itemize expenses.  And only the amount of job-related expenses that exceed 2% of your adjusted gross income are included as itemized deductible expenses.

See more information on deducting a home office below:

https://ttlc.intuit.com/replies/3302005

TurboTax will help you determine if your office is deductible (which would include the shared utility expenses).