The government gave local authorities 12 months to bring adopted local plans in line with the NPPF when it published the framework last March.
Under the transitional arrangements, councils with local plans adopted since 2004 were told that they could continue to give full weight to relevant policies "even if there is a limited degree of conflict" with the framework for a 12-month period (see panel).
After this timeframe, decision-takers must give due weight to relevant policies in existing plans "according to their degree of consistency" with the NPPF, the document says.
But with the end of the transition period on 27 March, just 23 councils (6.8 per cent) have plans judged to fully comply with the NPPF, according to data from the Planning Inspectorate (PINS).
Twenty-two of these have been previously unfinalised plans approved since the framework's publication, many of which had to take the new document into account by making changes mid-examination.
Just one authority - Mid Suffolk District Council - has revised its post-2004 adopted plan to bring it in line with the framework.
Another six have, in the last two months, published or submitted revised versions of their adopted plans to PINS for examination but these are yet to be approved.
Although almost half of councils (48.2 per cent) have adopted plans (see chart, right), the conformity of most of these with the NPPF has yet to be verified by inspectors.
Councils whose plans do not comply with the framework will be subject to the full force of the document's presumption in favour of sustainable development where a plan is "absent, silent or indeterminate".
The end of the grace period has sparked fears that areas without updated plans will be subject to a slew of unplanned development.
Countryside lobby group the Campaign to Protect Rural England (CPRE), which has been analysing local plan progress, has urged the government to extend the transition period by another 12 or 18 months to give councils more time to get plans in place.
CPRE planning officer Kate Horton said: "Now the transition period is going to be up, you can be fairly confident that many post-2004 plans will be judged out of date, especially as the economic context has completely changed in last few years."
Horton says anecdotal evidence suggests that more off plan sites are getting approved under the NPPF because so many local plans are out of date.
However, there does not seem to be hard evidence that the framework has caused more permissions for unallocated development than would have been given before.
The Department for Communities and Local Government (DCLG) said that plans adopted prior to the framework can still be NPPF-compliant. It argues that 70 per cent of councils have now published draft plans, so "it is not the case that communities will be at greater risk of unsustainable speculative development after March".
It said it is not intending to extend the implementation period, as this would discourage the remaining councils from producing up to date local plans.
But Alister Scott, professor of environmental and spatial planning at Birmingham City University, said emerging plans have little weight so will not discourage applications for development on unallocated land.
However, Liz Peace, chief executive of lobby group the British Property Federation, said: "Fears that the lack of a plan will lead to the untrammeled destruction of the countryside are overblown. Even where there is no local plan, development must still conform to the NPPF, which clearly sets out that development must be well located, well designed and sustainable."
Planning Officers Society president Malcolm Sharp said: "We are not going to be falling off a cliff at the end of the month. The NPPF came into effect as soon as it was published last year and there is no real difference now."
He said a lot of councils are using the NPPF alongside their adopted plans and will do a proper review in due course. "In terms of resources that's a sensible way to approach things," he said.
Andrew Whitaker, planning director at lobby group the Homes Builders Federation, said a year has been more than enough time for councils to review post-2004 adopted plans. He said: "Where councils are vulnerable to unplanned development is if they lack a five-year housing land supply. Paragraph 49 of the NPPF spells it out very clearly so that it does not matter when you adopted a plan if you don't have this."
Leonora Rozee, former PINS chief planning inspector and chair of the National Planning Forum mediation in planning programme, added that providing evidence for a five-year land supply was a long-standing requirement well before the NPPF.
Heritage charity the National Trust has also been conducting research on local plan progress with the Local Government Information Unit. The trust's head of land use planning Karin Taylor said the demise of regional strategies has introduced greater uncertainty into the process, as councils do not have firm housing targets anymore.
But Whitaker said the NPPF has not allowed councils to "simply stick their finger in the air" to pick a housing figure, as they have to show they have fully and objectively assessed housing needs and co-operated with neighbouring authorities.
The NPPF, published in March 2012, said that decision-takers could continue to give full weight to relevant policies adopted since 2004, "even if there is a limited degree of conflict with this framework", for 12 months following its publication.
The NPPF added that in other cases, and following the 12-month transitional period, due weight should be given to relevant policies in existing plans according to their degree of consistency with the framework.
The document also said decision-takers could give weight to relevant policies in emerging plans, according to: the stage of preparation of the emerging plan; the extent to which there are unresolved objections to relevant policies; and the degree of consistency of the relevant policies in the emerging plan to the policies in the NPPF.