The Victorian Civil and Administrative Tribunal (VCAT) has ordered property developer and land owner Peter Schierholter and Robert Trajkovski, of Plancorp Building Designers, to pay the costs of council's legal action against the Henry Street development.

The council has made a $24,414 claim, arguing it was deceived by a planning permit forged by Mr Trajkovski.

VCAT member Dalia Cook, who made an enforcement order on the site on March 9, said the council had a strong case for seeking the order and legal costs.

"The relative strength of the case for the responsible authority was overwhelming."

Ms Cook said the behaviour of Mr Schierholter and Mr Trajkovski in waiting until just before a second VCAT hearing to lodge new plans caused the council to rack up large legal bills.

Mr Trajkovski's "unlawful and inappropriate behaviour" in forging the documents also came under heavy criticism, as did Mr Schierholter's role in the affair.

"I fail to understand why the project draftsman would have taken this action unless he was encouraged or requested to do so by the owner-developer or was offered a financial incentive to obtain permission speedily," Ms Cook found.

She said Mr Schierholter's initial denial of having been served with the interim enforcement order created "concern about his credibility".

Council's general manager of city development Stephen Sully said the enforcement action was a necessary response.

"Seeking legal costs against the parties that carried out the illegal works is considered to be a fair and reasonable outcome, as a means of ensuring that parties that carry out illegal activities are penalised for their actions."

VCAT has ruled that by June 9, the developer must make a number of significant alterations to work already carried out illegally.

This includes rendering, ground level raising, and converting a garage back to a carport, unless council accepts the garage.

The costs must be paid within 90 days, with the final figure still to be assessed.