"We have building owners who don't want to do building strengthening until they have that security."
Sir Bob said buildings were always initially built "100 per cent" to code, but every six or eight years, that code changed.
The people who changed the code should also be morally responsible for helping building owners upgrade their properties, he said.
"But they don't pay for it, they don't offer interest free loans, they don't even allow us to deduct that cost - they say it's not an expense."
Most owners could not continually fork out for building upgrades, Sir Bob said.
He said there was a "prejudice" by some Government ministers against property owners.
"It's quite childish. Somebody's got to support these office buildings, they rent them, this government, they don't want to own them themselves.
"Obviously at the very least that expenditure should be deductible."
Mr Brown agreed that it was a great expense for owners.
"We have a whole range of buildings that could be strengthened if there was some assistance from the Government and indeed we've asked for that through the consultation submission that we made and we're also about to make separate submissions to Government."