Heritage Renovation Gets Lit Up With a Clever Glass Floor

Many major cities have their stock of historically significant buildings that need to be preserved, as they tell important stories about the past. That means that generally one can't unilaterally go in and change the outer appearance of a building that has been designated with heritage status, and any new renovation has to follow certain guidelines that municipalities have set. This helps to keep the architectural and cultural character of a neighborhood intact—not to mention that the greenest building is often the one that is still standing.

That can present problems when homeowners want to update an older building to make it more spacious or more energy-efficient. In Melbourne, Australia, Ben Callery Architects (previously) got creative in renovating an early 20th century heritage terrace house in the neighborhood of Rathdowne Village, in the suburb of Carlton North. Local rules dictated the facade of the terrace house had to be maintained, and that any additions should remain mostly out of sight.

The clients for the project were returning back from living abroad for many years. As parents of grown children who have fled the nest, the couple were receptive to new design ideas about how to make the most out of a small house on a small lot. This terrace cottage is the "perfect property for downsizers," but as the architects explain:

"The only problem was [the house's] orientation, north to the front, with the heritage requirement to keep the façade and not see any additions. Given that the property is only 5 meters (16 feet) wide and 120 square meters (1291 square feet) with neighbouring walls on both side boundaries (two storey to the east boundary) getting sunlight into living rooms at the rear and creating a connection with the elements is very difficult! [..]

The house would need to be two storey to accommodate their brief. And being such a small property there was no excess space to create voids to draw sunlight into the ground floor."

To solve this problem of having two stories but not enough light, the architects came up with a clever design idea: a 1.18-inch (30millimeter) thick glass floor that would allow light to pass through to the first level, without losing precious floor area. The designers say:

"The glass floor visually connects this space with the living rooms below while maintaining acoustic separation."

Essentially, the architects' design philosophy was simple: to extend the feeling of spaciousness and light by carefully placing window openings to bring light or a view of the greenery in.

The two front rooms were retained, and are now delegated as a guest bedroom, or as a second living room.

To maximize the living space on the first floor, the bathroom has been wedged in the middle of the floor plan, between the guest bedroom and the kitchen and living room in the rear. A living wall of plants was added to bring nature in.

The glass floor successfully connects the lower level with the upper level, which includes a second living area that opens out onto the roof terrace, peeking out over the existing parapet.

At the other end of the second-floor addition, we have the master bedroom, which is topped with an operable clerestory window, strategically placed for optimal natural cross-ventilation.

Right below the glass floor, we have the kitchen, where the timber cladding of the roof deck wraps down to make an appearance, highlighting the continuity between the spaces.

The design incorporates a simple palette of materials and colors, all of which serve to soften the roughness of the original brick walls. There is also good use of some reflective surfaces, which help to give the illusion that the space continues beyond.

The brick on both sides has been painted white to make the space feel brighter and more open. In contrast, the steel beams supporting the new addition above are painted matte black and stand slightly apart from the existing wall.

Despite the difficult constraints of size, and those laid out by local preservation regulations, the architects have managed to create a space that feels open, modern, and intimately connected with its urban and natural surroundings. It's no small feat and a good example of how such heritage renovations can be done skillfully.

To see more, visit Ben Callery Architects and Instagram.