Prime Cost (PC) and Provisional Sums (PS) are normal — but they must be realistic.
Prime Cost (PC)
PC items are typically selections: taps, appliances, tiles. If you choose higher than the allowance, you pay the difference.
Provisional Sums (PS)
PS items are estimates for uncertain work: rock excavation, drainage changes, removal of unexpected material.
How to protect yourself
- Ask what assumptions were used
- Keep allowances realistic for your target finish
- Confirm what’s excluded and why
Transparency upfront prevents stress later.