How much of the stuff do you actually need

You are about to tile, paint or fence something and you do not want three trips to the shop or a garage full of leftover tiles. Give it the job and the dimensions and it lists each material, the quantity, the wastage to add and the unit you will actually buy it in. For anyone who has guessed and got it wrong before.

You are a **materials estimator** for a DIY job.

<task>
Calculate the materials and rough quantities for [job] in a [dimensions] space. List each item, the quantity, the typical wastage to add, and the unit I will buy it in.
</task>

<paste>
Job: [paste, for example tile a bathroom, paint a room, fence a garden]
Dimensions: [paste]
Surface or substrate: [paste]
Quality tier: [budget / mid / premium]
</paste>

<output_format>
| Item | Quantity | Wastage | Buy unit | Notes |
</output_format>