By Mike McKimm
BBC Northern Ireland environment correspondent
The government has moved to end the blight of building single houses at random in the Northern Ireland countryside.
From Thursday onwards, new plans will not be considered for single rural dwellings, with few exceptions.
The Mournes area has recently seen a surge in single house building
The move ends a stampede which has seen planning departments all but overwhelmed by tens of thousands of speculative plans.
Faced with a move towards more controlled sustainable development in line with the rest of the UK, the planners had little choice but to crack down on this type of housing.
The Department of Regional Development, which announced the move, said that there was ample land already identified for building in all parts of Northern Ireland to cope with housing demand for the next five to 10 years.
But the move is bound to anger developers, builders and would-be rural home owners alike.
Currently three times as many single houses are being built in the countryside in Northern Ireland as in the rest of the UK in any one year.
For example, in the picturesque Mournes area, more than 3,500 new single houses were built in the last four years, angering conservation and environmental groups. They will welcome the latest move.
From now on, only houses for farming families or for retiring farmers will be allowed, and only if the case can be proved.
Some homes will be allowed for key employees for certain types of industries and there will be a special allowance for social need to help young or low-income families stay in rural areas.
The move will anger many farmers who looked to the sale of land for building as part of their income in difficult times.
In the past, some could get as much as £100,000 for a single site. Those days are over.
The move is, in effect, a moratorium, as the policy will not become law until later this year, following a period of public consultation.
But there were fears that this period would encourage literally tens of thousands of additional applications as people tried to beat the eventual ban.
Planning Minister Lord Rooker said that the measures were designed to save the countryside.
"We are wasting the countryside by pepper-potting it with dwellings that are not sustainable - which require motorcars, which require massive numbers of septic tanks, which actually help destroy communities.
"What we need to do is preserve the villages and towns by enabling them to grow."
Jim McColgan of the Rural Area Partnership said: "One difficulty is the restriction on farmers perhaps selling a site to raise funds to maybe diversify into some other area of business.
"This is particularly now that they are under financial stress and strain."
Community groups are worried younger rural families will suffer.
Rural community worker William Houston said: "In many cases they won't be able to get planning permission in the countryside to build a house.
"If a home in their area comes on the market, it will be priced according to the lack of new build and it will be priced out of the market for them."
Libby Clarke of Joyce Estate Agents said no-one wanted to spoil the countryside or areas of outstanding natural beauty.
"However, we would recommend that the planners look at adjustments where they would make reasonable height restrictions or density issues and people work to those guidelines."
Friends of the Earth campaigner Lisa Fagan said that the policy was necessary to prevent "Donegal-style development".
"No doubt there will be an outcry in response to today's announcement from farmers intent on selling sites for building, but government must stand up for the public interest."