The architects at Archi-tectonics came up with a stylish and considered design which elevates this London townhouse extension to another level.

Treehouses are lovely, but they also tend to be small and rather too rustic for our liking. Casa Santa Maria Del Oro is not a treehouse, but rather a house with trees growing through it. The effect is similar, but infinitely more spacious and sophisticated.

Some say rectilinear and rounded forms don't mix well, but this striking house, designed by Steven Harris Architects and the interior and landscape designers at Rees Roberts & Partners, is here to prove the critics wrong.

Concrete as a construction material has somewhat of an image problem, forever associated with brutalist highrises and dull utilitarian buildings. In the hands of artist and designer Omer Arbel, however, concrete has taken on a fresh, almost poetic expression.

Architecture aficionados will be well familiar with Fallingwater, the iconic modernist house perched on a rock face with cantilevered floors overlooking a waterfall. Tucked away in an idyllic corner of California is a more contemporary house but with a setting and design every bit as breathtaking as the Frank Lloyd Wright masterpiece.

At first sight, Casa 15, designed by Porto-based AM-Arqstudio, appears to be an unremarkable modern villa with sleek, minimalist lines and rectangular volumes. Closer inspection reveals a wealth of design details which elevate the senses.