A significant number of UK service personnel could be living in poor quality accommodation for the next 20 years or more, a report has claimed.
Pictures of poor conditions were sent to the BBC by soldiers
The National Audit Office study says more than 40% of homes are sub-standard with no final date for an upgrade.
While many improvements have been made, more resources are needed, it adds.
Defence Minister Derek Twigg accepted there were problems with some living quarters but said more than £5bn will be spent over 10 years on improvements.
The Ministry of Defence is the second largest landowner in the UK and has a worldwide estate valued at £18bn.
The report - which looked into the management of the MoD's estate - estimated that the total operational costs in 2005/6 were £3.3bn.
The report says much has been done to improve service personnel's accommodation, and in some cases, targets have even been exceeded
Since 2001/02, about 20,000 single living "bed spaces" have been built and about 12,000 service family houses have been upgraded.
However, out of an estate of 46,800 homes, more than 19,000 remain below the "standard one" benchmark, it says.
It goes on to say: "The scale of the remaining problem is, however, such that unless more resources can be found, a significant number of service personnel and their families are likely to be housed in poor quality accommodation for 20 years or more."
Conservative MP Edward Leigh, chairman of the Commons Public Accounts Committee, said the MoD faced a "battle royal" to improve homes.
He said he acknowledged work was being done to address the situation but was unsure whether resources were being targeted in the right way.
"While roofs are left to leak, money has been found to build new sports pitches.
"It is not right that, here in the UK, they should have to put up with shabby living and working quarters," he said.
Sammie Crane from the Army Families' Federation told BBC News there had been "years of neglect and underinvestment".
"If this country is going to commit troops overseas it's got to look after those troops, and one of the ways is housing them properly and making sure there's a proper investment," she said.
"There is money going in but it needs to be more, it needs to be targeted."
Mr Twigg though said: "Armed Forces personnel and their families deserve good quality accommodation, and the MoD is committed to providing this.
"We acknowledge that there are problems with some service accommodation, and are working hard to improve it."
In January, BBC News published pictures sent in by soldiers of barracks and shower blocks with cracked walls, mildew and broken pipes.
At the time, Chancellor Gordon Brown pledged to improve military accommodation.