Budgeting: New column is needed, named as 'FIX', which is for selecting those costs, which can not be changed (like heating, lighting, water, etc. costs).
This column should have only one value. Yes, if the cost is fixed. The other values should be left empty.
Also the Budgeting columns should be possible to be sorted by values, like FIX or Amount, Estimated, Actual, etc.