How a firm's grade works

A firm's grade on defects.sg is three letters, like ABA. Nobody types it in. It is worked out every night from the record of the firm's projects.

What it measures

Only what the firm did with each defect list:

• How much got resolved. Serious work counts for more than small touch-ups. A defect the homeowner settles privately with the firm counts as resolved.
• How fast. A fix within 4 days earns full marks. The marks fall to nothing at 30 days.
• Whether the fix held. The share of fixes the homeowner accepted the first time.

Each finished project gets a letter from A to E. A typical firm gets a B.

What it leaves out

• How many defects were raised. That says as much about the homeowner as the firm.
• The size of the contract.
• Defects raised in the last 14 days before sign-off.
• Defects a firm found and fixed itself.
• Whether a fix met a particular standard. The homeowner accepts or rejects each fix; we don't judge the workmanship.

Reading the three letters

The letters come from the firm's last 10 finished projects, read left to right:

1. Typical: the middle project.
2. Average: every project counted, so one bad job pulls it down.
3. Most common: the letter most projects got.

AAA means excellent every time. ABA means usually excellent, with one or two bad jobs. BBB is typical.

New firms

A firm with fewer than 3 finished projects shows "- - -". That is an empty record, not a bad grade. With 3 or 4 projects it shows two letters and a dash, and from 5 projects all three.

What nobody can change

No firm can buy its grade, and nobody edits one by hand. If something in the record was wrong, correcting it changes the grade on the next nightly run. A grade, once earned, stays published.

A grade isn't a review. It says nothing about taste, price, or whether you'll like working with the firm.

The full method, with every weight, is on How grades work.