Cost centres and sets

A cost centre is one running cost line for a house. Electricity is a cost centre. Gardening is another. Breakfast is another. Every line holds four things: a Label, a Category, a Unit and a $ Amount.

One amount for the whole house, divided by participants

This is the point worth reading twice, because it differs from the way many providers build the same numbers in a spreadsheet.

Each line holds a single amount for the whole house. SILWise then divides that amount by the number of participants living in the house. There is no grid of amounts by bedroom, and nowhere to type a different figure room by room.

An example. You enter $900 for electricity on a line billed per 90 days, and three participants live at the house. That is $300 each for the 90 days, which SILWise converts to the figure a calculation actually shows: $46.67 a fortnight each. Move a fourth participant in and the same $900 line becomes $225 each, or $35.00 a fortnight, with nothing retyped. You change who lives there, not the cost line.

One exception is worth knowing. On a house’s own page you can put an individual participant on their own amount for a line. That amount is carved out of the line total first, and the remainder is shared between everybody else.

Bedrooms never divide a running cost. They drive a separate thing: house rent is split by the number of bedrooms, not by the number of participants. See houses and bedrooms for the difference.

The two units

The Unit dropdown offers exactly two choices, and they behave differently.

• Per house, per 90 days is one shared bill covering the whole house for 90 days. This is the unit SILWise divides by the number of participants. Use it for utilities, repairs, gardening, consumables and most levies.
• Per participant, per week is already a per person price, so nothing is divided. Enter $45 for dinner and every participant who has dinner switched on is charged $45 a week each. Adding a participant does not make dinner cheaper for anyone else.

In short: the first unit splits a shared bill, the second repeats a personal price.

The five categories

Every line sits in one of five categories: Utilities, Repairs & maintenance, Household supplies, Food and Other items.

The category decides where the line appears, both in the editor and in the per participant breakdown on a calculation. It also picks a sensible starting unit. A new line under Food starts on Per participant, per week, and a new line in any other category starts on Per house, per 90 days. You can change it.

What the On tickbox does

Each line has a small On tickbox. It is the default answer to the question “does a new house pay for this?”. When you set up a house, every line marked On starts ticked, and you untick anything that house does not pay for. Each house then keeps its own answer, so changing On later does not disturb houses you have already built.

Leaving the $ Amount blank is allowed while you are still gathering bills. If a blank line is switched on for a house, the calculation stops and tells you rather than quietly treating that cost as zero.

Why lines live in sets

Lines are grouped into a set, which is a named library of cost lines. Each house links to exactly one set, so a set holds one agreed set of prices that several houses can share.

That grouping is what makes a yearly cost review safe. Use Duplicate to copy a set, update the prices in the copy, then point houses at the new one. Anything you have already saved keeps the figures it was saved with. Rename and Archive keep the list tidy. Archive only works once no live houses are linked to the set, and an archived set can no longer be linked to a new house.

Next

Ready to build one? Follow set up cost centres.