Richard Devon is one of only four unit owners to give evidence at an inquiry established after high profile Sydney unit building problems, including 300 residents of the Opal Tower forced to abandon their units on Christmas Eve because of defects, and similar problems at the Mascot Tower building in June.

Mr Devon said the Sydney unit problems mirror systemic building industry issues exposed shortly after the Landmark was completed in 2008, including the failure of regulators and respective NSW Governments to stand up for unit owners.

In a submission to the inquiry, which will start public hearings at 10.30am, Mr Devon said governments had been receiving "massive revenue" from stamp duty for years as residential units are sold off the plan and then re-sold, often on more than one occasion.

He said many unit purchasers had been "hoodwinked because of the non declaration of material facts, the farce with private certification, poor building techniques" and strata committees were left dealing with the "silent cover-up of building problems".

After years of trying to hold people accountable for defects in the Landmark that were apparent within a short time after it won a NSW Master Builders excellence in construction award in 2009, Mr Devon will tell the parliamentary inquiry "it is virtually impossible to force any person or entity to take responsibility for the faulty building practices with high rise buildings in NSW".

He will also tell the inquiry of the ugly side of the building industry scandal, after the death of an elderly Landmark resident in July only two months after returning to her unit following months of defect repairs, and the distress she experienced before her death after receiving anonymous letters.

In his submission Mr Devon said Landmark unit owners were unable to obtain "as built" plans for the building which was certified by a private certifier.

"Level 9, the top level, was subject to at least three changes in plans after the architects were dismissed, and the building company owned by the developer made these changes 'in house'," Mr Devon said.

"Notwithstanding this, no person or entity will supply these plans to myself and others who have requested them. The building, which was originally declared to be costing $20 million, has in excess of $4 million remediation necessary, mainly due to non-compliance with Australian Standards and manufacturers' specifications. There are many other remediation issues on other levels."

The parliamentary inquiry, chaired by Greens MP David Shoebridge who visited the Landmark earlier this year, will consider the role of private certification in protecting building standards, including conflicts of interest, effectiveness of inspections and the accountability of private certifiers; the adequacy of consumer protections for owners and purchasers of new apartments/dwellings, and limitations on building insurance and compensation schemes and the role of strata committees in responding to building defects discovered in common property.

Public hearings are set down for today, August 16 and 27.