Major Town Houses of the Architect Victor Horta

Run your hand along the banister, if you are allowed, and you will feel it curve away like a vine. Above you, pale light falls through coloured glass. Under your feet, a mosaic floor swirls in soft greens and ochres. Nothing here sits in a straight line for long. You are standing inside the world of Victor Horta, the Belgian architect who taught Brussels houses to grow like plants.

This is not one building but a group of four. UNESCO listed them together as a World Heritage Site in 2000. They are the Hôtel Tassel, the Hôtel Solvay, the Hôtel van Eetvelde, and Horta's own house and studio in Saint-Gilles. In French, the word hôtel here means a grand private town house, not a place to sleep for the night. Each one was built for a real family, in the years around the turn of the twentieth century.

To understand why these houses matter, picture Brussels in the late nineteenth century. Wealthy streets were lined with heavy facades that copied older styles, Gothic, Renaissance, classical. Horta wanted something new. He looked at the stems, tendrils and petals of nature. He looked at iron and glass, the materials of railway stations and greenhouses. Then he brought them into the home, openly, without hiding them behind plaster.

The Hôtel Tassel came first, in the early 1890s. It was built for Émile Tassel, a professor at the Free University of Brussels. Many historians call it one of the very first Art Nouveau buildings anywhere. Art Nouveau, meaning simply "new art", was a style of flowing lines that swept across Europe around 1900. Inside the Tassel house, the iron columns branch out at the top like young trees. On the walls and floors, painted and mosaic lines whip and curl. Designers later called this the whiplash line.

Here is something many visitors miss. Horta did not design only the walls. He designed almost everything — door handles, light fittings, radiators, window frames, even the furniture. He wanted one single idea to run through the whole house, from the facade to the smallest hinge. A visitor in the 1890s would have walked into a home where every object belonged to the same family of shapes. That total approach was rare, and it is still impressive today.

The Hôtel Solvay stands on the Avenue Louise, one of the grandest streets in Brussels. Horta built it for Armand Solvay, son of the chemist and industrialist Ernest Solvay, whose company made the family very rich. Here Horta had a larger budget, and you can feel it. Fine woods, rich stone and bronze details fill the rooms. The facade bends gently outward, so the whole front seems to breathe. Of the four houses, this one is often described as the most luxurious.

The Hôtel van Eetvelde was built for Edmond van Eetvelde, a senior administrator of the Congo Free State, the colony that King Leopold the Second ruled as his personal possession. That colony is remembered today for terrible abuse of the Congolese people. It is honest to remember this when you look at these elegant rooms. Some of the wealth that paid for Brussels Art Nouveau was linked to that history. Exotic woods and imagery from Africa appear in the house.

Inside van Eetvelde, Horta solved a difficult problem. The plot was narrow and deep, and light could not easily reach the centre. So he placed an octagonal hall at the heart of the house and covered it with a glass dome. Daylight pours down into the middle of the building. This idea, bringing light into a deep town house from above, appears again and again in his work. Look up, wherever you are, and you will usually find it.

The fourth house is the one most people can actually enter. Horta built his own home and studio on the rue Américaine in Saint-Gilles, at the end of the 1890s. Today it is the Horta Museum. The house and the workshop are two connected buildings. On one side he lived. On the other side, his assistants drew plans and made models. Walking through, you move between private family life and a busy architectural office.

The staircase is the spine of the museum. It rises through the house toward a skylight, and the rooms open off it at slightly different levels. As you climb, the light grows stronger and the colours grow paler. Horta used mirrors to make small spaces feel larger and brighter. In the dining room, notice the glazed white brick on the walls. It is a material more common in kitchens and stations, but here it looks polished and calm.

Now a quieter, sadder story. Horta also designed a famous public building in Brussels, the Maison du Peuple, a headquarters for the socialist movement. It was demolished in 1965, despite protests from architects around the world. Its loss shocked many people. It helped push Brussels, and Europe more widely, to take the protection of nineteenth and early twentieth century buildings more seriously. In a way, the survival of these four houses carries the memory of that lost one.

When you walk between the houses, keep your eyes on the street too. Saint-Gilles and the neighbouring district of Ixelles are full of Art Nouveau facades by Horta's followers and rivals. You will see curved iron balconies, painted panels called sgraffito, and doors framed in flowing wood. Not all of them are by Horta. But they show how quickly his ideas spread. For a few years, Brussels became one of the great laboratories of this style.

So pause for a moment where you are. Look at one detail, just one. Perhaps a door handle shaped like a twisting stem, or a beam of coloured light on the floor. More than a century ago, someone drew that line by hand and decided it should feel alive. As you step back onto the street, listen to the trams, notice the ordinary houses beside you... and see how gently Horta's curves still stand out among them.