What Are Clerestory Windows and Their Spatial Advantages in 24 Projects

Written by James Wormald
Published on August 16, 2023

Not nearly as complex an architectural typology as the word suggests, a ‘clerestory’ is a simple – if lexically loose – a portmanteau of ‘clear’ and ‘story’. Denoting a section of the wall that contains windows or cavities above eye level. The word is often assumed to have a religious context. Clerestories historically appeared at the upper levels of Roman churches, Hebrew temples, and early Christian architecture after all. And the earliest references we have to the feature come from religious texts.

Today, religious structures are often typified by the light their high windows allow to stream in, both figuratively and literally, from a higher source. At the CES Chapel in Taiwan, for example, ‘light diffuses through the glass clerestory and brightens the apse throughout the day,’ explains JJP Architects & Planners, about an interior design concept driven by natural lighting, ‘the chapel is filled with a spiritual aura, with a bright cross projected deep into the space.’

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As an architectural feature, however, clerestory windows are found in many projects of all types and periods. Due to this control of natural light, along with natural warming, ventilation, and many more effects, clerestory windows are an important part of contemporary low-energy buildings and are becoming ever more popular in modern projects.

Different Types of Windows and How to Use Them

The Natural Lighting Effects of Clerestory Windows

Replacing walls with transparent windows is an easy way of bringing more light into an interior, but wherever there is more light, there’s also a reduction in privacy. A great advantage of clerestory windows, however, is that by staying high up the wall, outdoor sightlines are reduced. At the Rau Haus in Portola Valley, US, by Feldman Architecture, for example, ‘light wells and clerestory windows on the eastern facade welcome morning light and peeks of greenery without compromising privacy,’ state the architects.

What Are Clerestory Windows and Their Spatial Advantages in 24 Projects - Image 2 of 35 — © Adam Rouse

Meanwhile, by applying a sawtooth roof to the CABQ International District Library in Albuquerque, US, RMKM Architecture has been able to add ‘north-facing clerestory windows for glare-free natural light and sky views 12 months per year,’ as the architects explain, in addition to south-facing PV panels, too.

Winter Warmth with Clerestory Windows

‘A set of clerestory windows cap the ends of the gable roof, framing a Turrell-esque sky view,’ explain architects Sonelo Design Studio about the Gable Clerestory House in Melbourne, Australia, referencing the American natural light artist, James Turrell, whose work uses architecture to form naked-eye observatories that frame the sky. But there’s another reason why the studio chose to add the clerestory gable where they did. Being higher up the wall, the window extends daylight hours and ‘heats the space with warm winter sun during the colder months.’

What Are Clerestory Windows and Their Spatial Advantages in 24 Projects - Image 3 of 35 — © Pier Carthew

While high clerestory windows warm interiors with the low-angled sun during the winter, the addition of any glazed surface can add unwelcome heat gain during the summer, too. At the Rescobie Pavilion in Rescobie, UK, a ‘mono-pitch roof brings low autumn and winter sun into the space through clerestory glazing,’ share the architects, Kris Grant Architect, ‘while a deep overhang provides shade in the summer months.'

Creating Passive Ventilation With Clerestory Windows

When open, clerestory windows use their height to suck warm air in their vicinity up and out of the interior, replacing it with cooler, low-level air from below. Directing the natural airflow into, through, and out of a building using efficient passive cooling and ventilation techniques such as clerestory windows is an important part of modern low-energy buildings.

What Are Clerestory Windows and Their Spatial Advantages in 24 Projects - Image 4 of 35 — © Rory Gardiner

James Gorst Architects’ Temple Complex in Rake, UK, for example, ‘naturally cools internal spaces with fresh air supplied by an underground labyrinth ventilation system,’ explain the architects, ‘while high-level actuators in the temple clerestory allow warm air to escape.’ Meanwhile, at the Narbo Via Museum in Narbonne, France, inspired by Roman technology, Foster + Partners combine clerestory windows with a ‘subterranean void that pushes cool air out at a low level,’ as the architects describe, and ‘high ceilings which create a thermal flywheel effect, naturally pushing warm air upwards, from where it is exhausted.’

The Spatial Advantages Formed by Clerestory Windows

By freeing up the obstructions between second-story clerestory windows and first-floor spaces, projects that use them can reap the rewards of higher ceilings. At the Sandi Simon Center for Dance at Chapman University in Orange, US, for example, the sawtooth roof allows several rows of clerestory windows to flood double-height communal areas inside the large building with light. An additional benefit, however, was that the ‘strategy amplifies the enormous trusses that hold up the building’s culturally and historically significant shell,’ share Lorcan O’ Herlihy Architects.

Wherever space is gained, however, it is also lost elsewhere. While clerestory windows at the Hidden Garden House in Sydney, Australia, add space in the first-floor ceiling, they also cause the balcony terrace to ‘rise almost a meter above the floor level of the main bedroom,’ share Sam Crawford Architects. Here, however, the change to the balcony’s pitch allowed a roof garden to point back towards the interior, creating a delightful presentation of greenery outside the rear windows.

Using Clerestory Windows as a Fire-Protective Barrier

As Faulkner Architects correctly points out while describing work on the CAMPout project, ‘as climate change increases the incidence and magnitude of wildfire events and we continue to reach further into the wild landscape with development, we must enhance the construction systems and materials to withstand these disasters.’ Located on a dense pine forest near Lake Tahoe, US, the architects use thick concrete walls topped with steel sash tempered clerestory windows to ‘form a fire-resistive barrier and secure a native cedar interior,’ creating an environment that’s responsive and considerate of it’s setting and its local material palette.