Fashionable Antwerp is well-known for its historic buildings, many dating from the 16th or 17th centuries. A newly-renovated townhouse marries the old city with the new, in one very successful project from Sculp(IT) - featuring a world first.

From the street, the townhouse facade remains unchanged. For the owners, very little is the same because of a vast black metal-rimmed glasshouse added to the rear.

Antwerp architects Sculp(IT) say their conversion includes the biggest pivoting window yet installed. At three metres wide, by six high, it's simply huge.

The result is a light-filled residence that invites the garden in and opens up each floor to sunshine and sky. In a crowded city like this one, that is key.

Antwerp's a compact place, with 500,000 residents. The traffic is so bad - second only to big brother Brussels as the most congested in the world according to the INRIX Traffic Scorecard - that home needs to provide a calm, serene contrast.

Sculp(IT)'s renovation, in our humble view, achieves that.

A new concrete floor to the ground level anchors an open-plan eating and living space. On a mezzanine, there's a slim office space, while at the front the original dining and living rooms gain a view to the garden at the back.

Second, third and fourth floors all gain a garden view.

Engineering this renovation wasn't easy. The result, like all great pieces of design, is so good it looks like it's always been there.