Peter Boggis has compacted clay specially delivered
A retired engineer whose Suffolk home is under threat from coastal erosion has started a High Court battle for the right to protect it.
Natural England wants fossil-bearing cliffs near Southwold to be allowed to wear away, raising the prospect that homes could fall into the North Sea.
But Peter Boggis, 77, has installed his own defences near his Easton Bavents home and is fighting to maintain them.
He claims Natural England is acting beyond its powers and cannot stop him.
Natural England declared the area a Site of Special Scientific Interest (SSSI) in 2006, with the intention of preventing Mr Boggis from maintaining his sea defence barrier.
Mr Boggis has argued that Natural England has no legal right to stop him saving his home.
Opening the two-day hearing, Gregory Jones, appearing for Mr Boggis, told Mr Justice Blair the purpose of SSSIs was normally to "conserve or preserve" flora, fauna or geological features.
But Natural England wanted to let the sea erode the Easton Bavents cliffs in order to expose the sediment and fossils so that they could be studied, he said.
Mr Jones argued that Natural England had no power to extend the scope of SSSIs "in order to study the destruction of the cliffs".
The intention of the law allowing SSSIs to be created or extended was "the preservation of physical features - not their destruction".
Mr Boggis's so-called "soft sea defences" consist of 250,000 tonnes of compacted clay soils he had specially delivered.
The controversial barrier has to be renewed as the sea washes it away.
Mr Jones told the judge: "These barriers do actually work and have had the effect of slowing the erosion of the cliffs."