But Herbert said large "community" jails would be a mistake, and not just for policy reasons.
"It will be easier to secure land and planning agreement for a number of smaller units than for big superprisons," he said.
Herbert says the government is reaping the consequences of ignoring for too long the problem of rising prisoner numbers.
The government plans to add an extra 9,500 prison places by 2012, but even that will be too few, based on Home Office projections for the rise in the prison population, according to Herbert.
He said the government was instead planning to solve the crisis by cutting the numbers going to prison and increasing the use of community sentences -- an approach he condemned.
"There is an existing demand from the courts to sentence offenders who are repeat, violent or serious offenders," Herbert said.
"And there is a demand to deal with those crimes from our society, in particular violent crime, and that requires us to incarcerate them."
Straw said last week he agreed with the Lord Chief Justice, Lord Phillips, who said that "some method must be found of linking resources to the setting of the sentencing framework."
What that means, said Herbert, is that if prisons are full, some offenders will be given a non-custodial sentence instead.
"The way to deal with the growth in the prison population is to deal with the reconviction rate," he added.
"The wrong way is to try and manage the prison population downwards by pushing people who should be incarcerated out into weak community sentences."
Herbert said the current prison population was largely made up of serious, violent or repeat offenders for whom non-custodial penalties were inappropriate, leaving little scope for cutting prisoner numbers.
"They have usually gone through the gamut of community penalties which have failed and have been imprisoned as a last resort."
