Construction is expected to begin next month, with workers already dismantling the courtroom slated to house the new infrastructure. The cost is unknown.

When completed, the new secure courtroom will hear high-security, bail and custodial matters.

The ACT is unusual in Australia in not having docks in any of its courtrooms after they were removed in the 1980s.

Defendants currently sit at the bar table with their lawyers and are separated from the public by a railing.

The news has been treated with caution by the legal fraternity, with many concerned a dock could prejudice the defendants' rights.

The idea to install a dock in a secure courtroom, which would protect the public and defendants, was first raised by Chief Magistrate Lorraine Walker last year.

Ms Walker, who declined to comment on the issue, wrote in an industry publication at the time that the court often dealt with people who were intoxicated or in acute mental distress.

She said the behaviour of such people could be unpredictable, posing a significant risk to other court users.

''Whether it takes the form of abuse, spitting or other physical contact, this is not a risk to which prosecutors and others should be unnecessarily exposed,'' she wrote.

The office of the Director of Public Prosecutions has said previously it supports the dock's reintroduction.

A final design has not yet been approved, but the government said a draft proposal favoured a "desk-type arrangement with timber surrounding to waist level and a transparent screen between the dock and public gallery".

The ACT Bar Association initially strongly opposed the original dock design, which resembled a glass box.

But chief executive Svetlana Todoroski said the association would not resist a design similar to the one used at Queanbeyan Local Court as it provided security without intruding on a defendant's rights.

ACT Law Society president Noor Blumer said the dock, once installed, should only be used as a last resort when extra security was appropriate for safety reasons.

''If the dock is designed so that it is not obvious that the accused is restrained, is comfortable and

allows the accused to confer confidentially with their lawyers, then it is unlikely to offend the Human Rights Act," Ms Blumer said.

But defence lawyer Ben Aulich said the advantages of a dock were overwhelmingly outweighed by the disadvantages.

Mr Aulich said a courtroom was designed in a particular way to assist in the administration of justice.

"Juries generally face the witness box to assess each witness and judges and magistrates sit higher to reflect the power they have to run the court and administer justice," Mr Aulich said.

"A dock sends the wrong message - that is, the accused needs to be caged because he/she may be dangerous.

"It also makes it much harder for a solicitor to take instructions and speak with their client."

Mr Aulich said the government should spend the money appointing a fifth judge to the ACT Supreme Court. "That is what we really need,'' he said.