A radical overhaul of Ofsted’s inspection regime will not include routine no-notice “dawn raids”, although schools could face more frequent scrutiny and receive gradings for their curriculum, the watchdog revealed this week.

The news that Ofsted no longer plans to bring in routine snap inspections will come as a relief to many headteachers, but could be seen as a U-turn from chief inspector Sir Michael Wilshaw, who has twice called for their introduction.

The announcement came as Ofsted launched a consultation on plans to revamp the inspection process and introduce a single framework for schools, early years, and learning and skills providers.

All institutions rated as good, it is proposed, will be subject to shorter, more frequent inspections: every three years instead of every five. These are likely to be carried out by a single inspector and last for one day rather than the usual two. Schools rated as outstanding will still be exempt from routine inspection.

Sir Michael said yesterday that in the past year alone, 860 schools, attended by 335,000 children, had experienced a drop in their Ofsted grade.

“At the moment, it can be five years or even more between inspections for a good school or provider,” he said. “This is too long. It’s too long for parents and employers. It’s too long for us to spot signs of decline and it’s too long for improving institutions to show that they are now delivering an outstanding standard of education.”

The three-year intervals are still longer than the two-year cycles first suggested by Sir Michael in April.

The watchdog is also considering introducing a new grade for “quality of curriculum”. This is currently built into the wider “leadership and management” category, but the proposal signals a shift in focus by the watchdog.

It is particularly pertinent for academies, which are free to deviate from the national curriculum. Last month, Ofsted’s outgoing national director of inspection reform, Michael Cladingbowl, told TES that the watchdog was keen to ensure primaries did not focus too narrowly on maths and English at the expense of a “broad and balanced” offering.

The decision not to introduce routine no-notice inspections will be the biggest surprise for many, as Sir Michael has been arguing in favour of them since 2012.

Having dropped the idea in the face of widespread opposition from the teaching unions, he revived it this summer after investigations into the Birmingham schools embroiled in the alleged “Trojan Horse” Islamist takeover plot.

This incident had “served to reinforce my original view that no-notice inspections for all schools are the best way to make sure that, for every school we visit, inspectors see schools as they normally are,” he claimed.

But the chief inspector revealed yesterday that no-notice inspections would not be part of the reforms. “I have already broadened the criteria Ofsted uses to judge whether an unannounced inspection is required for particular schools,” he said. “After careful consideration, I have therefore concluded that we do not need to consult on moving to routine no-notice inspections at the present time.”

The news was welcomed by Russell Hobby, general secretary of the NAHT headteachers’ union.

“Headteachers have a right and a need to be present during inspection and a small amount of notice is required to make this possible,” he said. “At present the period of notice is only half a day: anything less risks making the inspection invalid. Inspection teams will have questions about data and school policies, and this requires the headteacher’s presence.”

The consultation also proposes broadening the existing criteria on which schools and other providers are graded. Under the plans, existing “quality of teaching” will be renamed “teaching, learning and assessment”; “achievement of pupils” will become “outcomes for children”; and “behaviour and safety of pupils” will cover “personal development, behaviour and welfare”.

Stephen Ball, principal of New Charter Academy in Greater Manchester, said that Ofsted’s announcement on snap inspections was “a positive step”.

“There are practical issues, such as inspectors receiving an inadequate experience if they visit on a non-typical day and it’s more about catching people out rather than working with professionals as colleagues,” he said.

The consultation on the proposals, which are due to come into effect in September 2015, ends on 5 December.

`If you know it’s coming, you can plan’

Parkside Community College, rated good by Ofsted, is one of the schools which would be affected by the proposed changes. Andrew Hutchinson, executive principal of the Cambridge secondary, welcomes the proposed move to shorter but more frequent inspections for good schools.

“I prefer the more regular inspections,” he says. “A regular check with an HMI [Her Majesty’s Inspector] coming round would help to ensure you’re on track and pick up any issues, but also give you the opportunity to demonstrate your improvement.”

He adds: “If you know it’s coming, you can build it in as part of your planning. Ofsted is effectively saying it’s a partner in helping you get things right. It is a more grown-up way of doing it.”