WINDOW RESEARCH INSTITUTE

How do you create a house that can be maintenance-free for 50 years and last for at least 150 years? The Brick House, designed by the Denmark-based architect duo Leth & Gori as part of an initiative to develop affordable, low-carbon homes, offers one solution. We spoke with Uffe Leth and Karsten Gori at their office in Copenhagen to learn why they opted to make use of a classic building material like brick in their approach.

 

How did the Brick House (2014) project begin?

 

Leth: The Brick House project began with a competition involving three or four teams. It wasn’t about presenting a design but rather proposing a vision. The competition was held as part of a bigger project consisting of several houses (The Mini-CO2 Houses), each developed with a different focus on how to make a low-carbon house. We were asked to devise a method for constructing a house that would not require maintenance for the first 50 years and would have a minimum lifespan of 150 years. Our approach was to reference traditional Danish dwellings and emphasize the use of brick as the primary material.

 

What was the reason behind the requirement for a maintenance-free house?

 

Gori: The idea came from the client, an architectural association called Realdania. They fund housing projects, so they are very concerned about what homeowners are interested in. In Denmark, there’s significant interest in low-maintenance homes. The idea is that if homeowners do not have to constantly engage in tasks like repairing or repainting, they can instead focus on their lives. This also has significant design implications because it limits the choice of materials, necessitating the use of robust materials that can be used in their raw form, without paint finishes. In a way, this requirement for no maintenance naturally pointed us towards considering new ways of utilizing the kind of materials used in traditional housing that naturally become more beautiful as they age.

We also gave ourselves a self-imposed challenge to depart from the complexity of modern multi-material, multi-layered building assemblies, focusing instead on simplifying the construction process. This led us to construct deep 55-centimeter-thick external walls composed only of clay-based materials: brick and brick block (clay block).

What kind of material is brick in Denmark?

 

Gori: Brick is a locally sourced material. You could say that its use in architecture here is a tradition literally born from the earth of our land, as it’s made from the layers of soil that lie beneath Denmark. Those medieval churches built with stone, clay, and chalk that you may have seen—in a way, they’re sections of the Danish landscape.

Traditionally, clay and brick constructions were massive. However, with the advent of new technology like extrusion, it has become possible to make lighter brick materials, such as brick blocks containing numerous air pores, which also provide insulation. In the Brick House project, we solely relied on such brick blocks for insulation, without using any additional insulating materials.

 

Leth: In Denmark, the frequent rain and significant temperature shifts create a challenging environment for houses. Over the past century, there’s been a focus on enhancing home airtightness, leading to increasingly layered exterior walls. Brick houses built a century ago allowed for “breathing”, creating healthier living environments. However, modern houses, tightly sealed almost like plastic bags, require extensive ventilation systems. Building envelopes are no longer as porous as they once were, so they prevent the natural movement of moisture in and out. The Brick House’s wall system addresses this issue. We used traditional bricks on the outer side and bonded them to the large brick blocks on the inner side, creating a structure that can absorb and release moisture as temperatures change while presenting a kind of an unfinished open-veranda feel to the interior.

 

Gori: It acts almost like a natural air conditioning system.

Leth: And we achieved this using common products. Since the client required a low-budget house, we had to find ways to build it using relatively inexpensive standard materials. It needed to be just as affordable as a traditional house. During the design process, we drew inspiration from an early 20th-century Danish organization that advocated for collaboration between builders and architects. Known as the National Association for Better Building Practices (Landsforeningen Bedre Byggeskik), they developed a design manual for constructing brick villas, educated builders, and built schools and many houses. These brick houses remain attractive, featuring excellent proportions, spaces, and details. Even after a century, they can still be considered among the best of such architecture, demonstrating enduring quality.

 

But you needed to design a house intended to last for 150 years, which is an even more extensive amount of time. Did you make special design considerations in anticipation of future changes in trends and the surrounding context?

 

Gori: Buildings often shift functions, but the function of a house, particularly one meant to last 150 years, will consistently be to serve family life. Our aim was to create spaces that can be adapted over time if needed, even while understanding that human needs haven’t fundamentally changed over the past two centuries. We strived for a simple design that outwardly resembles a traditional home and yet transcends specific time periods. Inside, however, it contains a bigger space equipped with various features not found in traditional houses, but integrated in a very low-key way. We also kept the spatial organization simple in order to facilitate future modifications to the walls and openings. Structurally, too, this house, constructed with brick and brick block rather than concrete, allows for relatively easy remodeling by future generations. We also provided hidden attic spaces, which currently are not in use, for this same purpose of accommodating future changes.

The way we showcased the rawness of the materials without any paint finishes in this project, with its exposed brick and plywood walls, really shifted our aesthetic sensibility. This approach of using robust materials that suggest longevity opened us up to a new aesthetic, marking a departure from our previous designs.

 

Leth: One source of inspiration for this house was traditional Japanese architecture. Faced with the challenge of ensuring that the house would last for an extraordinarily long time, we envisioned a large roof that protects the exterior walls, windows, and all the various other building components, thereby extending their lifespan. This concept also resulted in an intermediary space akin to a Japanese veranda (engawa), where one can sit and enjoy, for instance, a morning coffee while sheltered from rain. The openings are fitted with sliding doors, too, which allow the interior spaces to seamlessly extend outdoors.

The placement of the windows, which face each direction, informed the layout of the floor plan. We aimed to create a situation where daylight streams through the spaces in both the east-west and south-north directions, making for a truly bright home. Orientating the windows in every direction was also important because we wanted to bring in all the different colors of daylight. The thick façade also forms part of this daylighting strategy, as the light not only lingers at the windows but also reflects off the deep reveals and niche walls. Actually, it would be more accurate to say that we designed the façade openings before we designed the windows. This approach led us to reduce the number of openings by merging a window and door into one opening, for instance, to offer simple, direct views to the outside from places like the living room.

Did you find there to be any unique challenges that come with a project with such a long-term focus?

 

Gori: There was the challenge of obtaining documented proof that anything actually has a lifespan of 150 years. It’s impossible to get a 150-year guarantee from manufacturers—any such guarantee would probably be meaningless anyway. So, the only real proof we could rely on were the buildings we looked at that have actually been standing for 150 years.

 

Leth: In Denmark, the standard service life for houses is 50 years. But for this house, we worked with engineers to achieve the international standards for listed buildings, which require a minimum service life of 100 years. This impacted everything from the design of the foundations to the amount of steel reinforcement we needed to use. While some of the solutions we implemented may have cost more in terms of carbon emissions, they ensure that the building’s lifespan is doubled.

 

Gori: Or tripled.

Leth: In reality, the lifespan could turn out to be even longer. The challenge of extending a building’s lifespan while simultaneously reducing carbon emissions is both technical and complex, and can potentially involve controversial decisions. There’s always a trade-off—to achieve one thing, you may have to pay for it with the other. With this house, we had to devise other ways to lower the overall carbon footprint because we made the decision to use brick and brick block, which are durable but quite carbon-intensive materials—as is concrete, of course.

One of our key discoveries from this project was that it can be very challenging to build in unconventional ways in Denmark. However, being pushed to use materials differently and rethink the design of a house from its very structure enabled us to expand the boundaries of conventional construction logic.

Contractors and builders generally prefer to work in ways that they are familiar with because introducing new methods introduces new risks, and with additional risk comes additional costs. We’ve been learning to manage this balance between drawing on conventional methods and taking on the risks of innovation. Embracing the new often means revisiting the old and reapplying time-tested methods from the past in a modern context. It’s a fundamental paradox in architecture.

In this project, we encountered another intriguing paradox: the concept of a “maintenance-free” house. I personally think it’s a rather foolish idea because regularly maintaining your house means learning exactly how it was built and how it works, which should help it stay in good condition for a long time. I believe that even little things like touching the building you live in and understanding the materials can actually help prolong its lifespan. We even tried to steer the client away from calling it a “maintenance-free” house, but we didn’t succeed in changing their perspective!

In Denmark, many people live in buildings that are at least a century old, and these structures are in excellent condition. This is because they have continued to be maintained and repaired. Their residents regularly engage in tasks like fixing roofs, replacing windows, and making various other minor adjustments, such as adding extra layers of glazing for better insulation. It is far more important to have people constantly interact with buildings and make small improvements and repairs than to leave them untouched.