The Quest for Sustainable Architecture

This story focuses on environmentally sustainable architecture, which aims to respond to this crisis by limiting the production of harmful carbon emissions and the exploitation of natural resources, to create buildings that are of long-term benefit to people and planet.  

Like concrete, glass can present a dilemma. Although tactical glazing can help reduce the need for carbon-intensive heating, systems are often only designed to last 30 years, resulting in more of the carbon emissions associated with their disposal and replacement. 

This situation has prompted the idea that "the most sustainable building is one that already exists". Yet older buildings can be thermally inefficient and not well suited to contemporary needs. Here's where retrofit comes in. 

Le Lignon, a 1960s housing development in Geneva, avoided the fate of demolition often meted out to estates of its period when it was retrofitted by Jaccaud Spicher Architectes in an 11-year project completed in 2021.

The retrofit of the estate, which was originally designed by Swiss architect George Addor, has improved its energy efficiency and living conditions for residents, giving it a new lease of life at a fraction of the environmental cost of wholesale replacement. 

Retrofitting also offers a relatively inexpensive way to enhance the thermal efficiency of existing individual homes, which in turn reduces their energy consumption. Arboreal Architecture carried out a 'deep retrofit' of this Victorian townhouse to reduce its energy consumption by around 75%. 

They stripped back the house to its shell of solid brick walls and re-lined the walls with insulation, airtight boards and new interior finishes to create a more energy-efficient home. 

In the 1990s and early 2000s, SolarCity took shape in the town of Linz, Austria. It was designed as a low-energy community initially for around 4,000 residents, with around a third of its energy drawn from solar power. 

It also drew from the principles of the Garden City Movement of the late 19th century, which emphasised planted green spaces within residential communities. Well-known architects were hired to design SolarCity's buildings, including Richard Rogers Partnership. 

The design, by Mikhail Riches with Cathy Hawley, tactically shades homes from the hot summer sun while encouraging the warming winter sun, resulting in 'passively' maintained comfortable temperatures without the need for 'active' carbon-reliant heating or cooling. 

The idea for  Passivhaus (or Passivehouse) design originated in Germany in the 1980s and 1990s. It was spearheaded by physicist Dr Wolfgang Feist, whose own family home, designed by architects Bott, Ridder and Westermeyer, was the first officially Passivhaus building. 

But the principles behind Passivhaus were not new. Long before the rise of carbon-based energy, buildings in hot climates employed features such as verandas, sunlight-deflecting brise soleil and heat-absorbing materials to passively maintain cooler temperatures.