An Elizabeth South man who worked unlicensed as a builder, leaving behind substandard work at a Munno Para West home, has been fined $5,000 and ordered to pay $7,500 to the consumer as well as legal costs.

Consumer and Business Services took action against 35-year-old Matthew Paul Evans after he solicited work on Gumtree, even though he wasn't appropriately licensed.

The Elizabeth Magistrates Court was told that Evans was contracted to install stormwater draining on the property, quoting $10,000 to do so.

Evans demanded and was paid $5,500 upfront - well above the $1,000 deposit allows by law for domestic building contracts below the value of $20,000. The consumer later paid an additional $2,000 to Evans to progress the works.

When the consumer refused to pay an additional $3,260 to finish the works, Evans stopped work and ignored subsequent requests for compensation to address his substandard work on the property.

Magistrate Ben Sale said that while Evans' offending was more based out of ignorance than a deliberate attempt to scam anyone, the building industry is regulated so that consumers can trust who they engage to carry out works are appropriately qualified and skilled.

He said Evans' work was incomplete and substandard, and he failed to take an opportunity to either explain himself to the consumer or remedy the situation.