Claiming business expenses

Hi, I work from home 100% of the time. I get paid per file I work and I make less than 20k per year. I do not receive a T4 and report all income as "additional income". Can I claim business expenses like office space, heating, electricity etc as well as computer equipment/hardware? Thanks in advance.

Filing

You can claim the expenses if you file as Self-Employed. If you just enter your income as "Other Employment Income" then you can't claim any expenses.