Prefabricated blocks from mass housing schemes are being torn down across the country's east as locals leave the economically downtrodden region in search of work.

A million homes in what used to be the German Democratic Republic stand empty, and 350,000 are due to be demolished within the next five years.

Until now, the concrete has been crushed for use in building roads, or even broken into pieces, spray-painted and sold to tourists as ``authentic'' graffitied Berlin Wall.

But now a team from Berlin's technical university, with a firm of architects, has developed the ``recyclinghaus.''

``The prefab buildings of the GDR-era might be lacking aesthetically, but structurally they could not be sounder,'' said Claus Asam, a structural engineer. ``We have the material already, so what a waste it would be if we didn't put it to proper use.''

House builders can save between 25 and 40 percent in construction costs by using the blocks' ready-made panels. Speed is also an attraction, as is the fact that the concrete is already dried out and solid from years of use - ``like an air-dried ham,'' in the words of Asam.

There is also the environment to consider. It would usually take about 22,700 liters of heating oil to produce the concrete needed for an average-sized family home.

Ingo and Beate von Zweydorff, as children of the communist GDR, grew up in a high-rise. But they always dreamed of living in something more homely.

``I always yearned for a detached house where I couldn't hear the neighbors, and for which I could choose the wallpaper,'' said Ingo von Zweydorff, 40.

Next month, the couple and their six-year-old daughter, Lina, will finally move into their dream home - a seven-room house recycled from a now defunct communist prefab, known in the vernacular as a ``worker's locker.''

They had to wait just nine days from the dismantling of a high-rise in East Berlin to the basic construction of their house.

Its architect, Herve Biele, aimed to design a house both functional and stylish and with no actual trace of its origins as a high-rise. ``The result is a modern, high-ceilinged house flooded with light,'' he said.

Critics have already compared this school of architecture to the utilitarian, but elegant, Bauhaus movement of the early 20th century. Since starting work on the von Zweydorffs' house, Biele has received 150 ``serious inquiries'' from others across Germany wanting a ``recyclinghaus.''

``Some, nostalgic for their communist childhoods, find the idea of living in a reprocessed high-rise quite romantic,'' Biele said. ``Others are simply looking for a way of cutting costs.''

The von Zweydorffs expect to pay around HK$1.64 million for their 2,300 square foot lakeside house, built out of 60 panels. It comes with under-floor geothermal heating, a winter garden, a roof terrace and a garage.