Self-employed

The Capital cost allowance section is for equipment, vehicles and other property that you use over several years, not for Business-use-of-home expenses. There is a separate section for that lower down on the page.

As to why the  household expenses are carrying forward, the amount you can deduct for business-use-of-home expenses can't be more than the net income from the business before you deduct these expenses. You can't use these expenses to increase or create a business loss. Unused amounts will be carried forward.