Clerestory Roofs: Everything You Should Know About
The roof is an integral part of any building. It creates the shape for the building and protects its interior from the weather elements.
However, today’s modern architecture demands much more than just a roof over the head. It demands a unique blend of function and style.
Roofs now have to perform multiple functions, while maintaining an aesthetic appeal. In this regard, clerestory roofs have emerged as the perfect option for architects and homeowners alike.
The clerestory roof stands out from most other types of roofs. Because it has the ability to let in a lot of natural light, support passive solar heating, and improve natural ventilation.
In this post, we will look at the key features of clerestory roofs and why they may or may not be the best option for building projects.
We’ll also take a closer look at some common examples of buildings that use these roofs, so you can get an idea of how they work in real-world settings.
What is a clerestory roof?
A clerestory roof is a sloping roof made up of high and low-slung roof panels that are joined in the center by a flat wall.
The sloping difference between the panels allows for window space, which is used to bring natural light into a building.
Clerestories (or clearstory windows) are small windows placed high up on the walls of buildings.
Some clerestory windows can be opened to let air into the room while others are fixed or non-operable, which means they cannot be opened for ventilation purposes.
Generally, any strategy that brings in extra daylighting in a building is a positive improvement. This is primarily because natural light has a positive impact on the moods of people.
Installing clerestory windows is a meaningful improvement because it allows daylight to penetrate into the spaces where otherwise it would not be possible. However, as with most things, there are certain caveats to consider.
Installing clerestory roofs will naturally change the heat dynamics of a building. It is therefore important to have an expert carry out proper heat loss calculations before going ahead with this design choice.
Ideally, the decision to install clerestory roofs should be made with the building’s orientation and prevailing weather conditions in mind.
Therefore it will always produce the best results if the building is initially designed with a clerestory roof.
Although it is possible to retrofit clerestory windows in an existing building, it is generally not recommended. It is important that you understand the implications of this design choice before making a final decision.
Installing clerestory windows on a two-story residential building can be achieved without much hassle if you work with a competent contractor.
However, if you are planning to install clearstory windows on existing commercial buildings things can get much more complicated.
Therefore, the decision to install clerestory roofs on an existing building should be taken with caution.
You will need to ensure that there are no structural or other issues before taking the plunge because such issues can be both expensive and time-consuming to resolve.
What are the considerations for using a clerestory roof?
There are certain considerations that you will need to take into account before installing clerestory roofs.
1. Building’s age and condition
Installing clerestory roofs on old buildings with poor structural conditions can be a risky business. Because you cannot predict how the roof will react to these changes and it may put people’s lives at risk.
Additionally, installing this type of roof is likely to make existing problems like water penetration even worse because they are more exposed now than before.
You may want to consider changing the entire design of your building if it is too old or difficult to repair.
This will ensure that you are not putting people’s lives at risk by attempting a DIY job on an existing structure with poor structural conditions.
Replacing clerestory roofs can be both expensive and time-consuming, which means you should only attempt a DIY job if you have the necessary expertise and resources at your disposal.
Even when done properly, replacing this type of roof can be quite disruptive to the daily life of occupants because it will require them to vacate their premises for an extended period while work is being carried out on-site.
If possible, try doing everything in phases so that the building occupants are inconvenienced for as short a time as possible.
Clerestory roofs are much easier to install on new buildings because you can design them from scratch.
Additionally, the structural conditions of such structures are usually strong and durable enough to support this type of roofing system without any issues whatsoever.
2. The building’s orientation.
Because clerestory roofs are designed to allow daylight they should be properly oriented to allow the maximum possible amount of sunlight in.
The ideal orientation for a clerestory roof depends on personal preferences and the location of the building.
Here is how placing clerestory windows in different orientations will affect the building’s daylighting dynamics.
| Orientation | Description | Pros | Cons |
|---|---|---|---|
| East/West-facing clerestory windows | Offers the brightest daylight in the morning/evening, and the light is more of a warm golden tone. | Provides a warm and cozy atmosphere in the building during the morning and evening. | May not provide enough light during mid-day and may not be suitable for buildings that require more light during the day. |
| South-facing clerestory windows | Gives the most light throughout the day since they receive the most sunshine. | Provides maximum sunlight exposure throughout the day, which is ideal for plants and individuals who need to work during the day. | May raise the building’s temperature and require additional cooling measures to maintain a comfortable indoor environment. |
| North-facing clerestory windows | Offers a darker indoor environment but even-lit space throughout the day as it does not receive too much direct light. | Reduces the amount of heat gain in the building and maintains a consistent indoor temperature. | May not provide enough natural light for individuals who require a bright indoor environment. |
2. The building’s function.
The function of a building also comes into play when deciding whether to install clerestory roofs.
If you will just use roof space to store things or have a more industrial purpose, you may want to forgo installing clerestory roofs altogether.
Why alter the building’s function to a large degree to allow daylighting if there is no real need for it? You can just opt for additional lighting instead to light up the area.
Also, if you already have a well-designed, functional building with a lot of existing windows, and daylighting features, then this type of roof will only be a cosmetic addition and will not be worth the trouble.
Finally, clerestory roofs are not the most ideal solution to introduce daylight into a building since they need structural modifications to be carried out on the building.
For this reason, if you just need a quick and easy way to improve the lighting conditions of your building then you should look into other means such as skylights, or tubular daylighting devices.
3. The type of roof.
The type of roof you have will play a huge role in determining whether or not it is possible to install clerestory roofs.
If your current roof design does not allow for this type of feature then the only way to do so would be by removing and replacing all of that structure entirely.
Therefore, just because your neighbor installed this type of roofing system, it doesn’t necessarily mean that your building can accommodate such a feature.
If you see the potential for installing clerestory roofs on your property then consult with an expert to analyze the structural conditions and determine whether or not your roof can support this type of feature.
4. The roof pitch.
The pitch of the roof is also very important to consider when designing clerestory roofs. To install clerestory roofs there should be a difference in the slope of roof panels so that they can form a space in between.
Therefore, if the roof pitch of your building is too low or the chance to create a slope in between roof panels is not possible, then installing clerestory roofs is not very feasible.
Most clerestory roofs need a minimum of the 15-degree pitch in order to work properly.
Depending on the distance from the ridge to the eaves of a roof a higher or lower pitch may be needed to achieve the desired results.
5. The building’s surroundings.
Another key factor to consider when designing clerestories is the surrounding landscape and environment, as this will affect how well natural light penetrates through your roof.
For instance, if you are building a clerestory roof structure in the middle of the forest where a lot of trees are present, this will prevent sunlight from reaching the roof and entering your building.
Therefore, you need to make sure that your building is not surrounded by trees or other structures which may impede the amount of sunlight entering.
6. Building code requirements
Last but not least, it is also important to consider the building code requirements in your area when designing clerestory roofs.
Since clerestory roofs are usually an intensive design feature, you need to make sure that your local permitting office will allow the construction of such a roof on top of your building.
If it turns out that they do not approve this type of modification then there is no point in going through with this project as it may end up costing more than it is worth.
Hence, you should always consult with the permitting office to verify whether or not they allow this type of construction before designing clerestory roofs for your building.
Pros and Cons of having clerestory roofs
| Pros | Cons |
|---|---|
| 1. Natural Light | 1. Increased Construction Complexity |
| 2. Ventilation | 2. Potential Heat Loss/Gain |
| 3. Energy Efficiency | 3. Higher Initial Costs |
| 4. Privacy | 4. Difficult Access for Maintenance |
| 5. Architectural Aesthetics and Appeal | 5. Compatibility with Building Structure |
There are many benefits that you can gain by opting for a clerestory roofing system.
Here are some of the main advantages to have in mind when thinking about this type of design feature.
Increased Daylight Exposure
The clerestory roof is one of the best ways to improve your building’s lighting conditions as it allows more natural light into your property.
This means that natural light can easily reach deep into your interior and this will improve the overall quality of lighting in your building, which makes it an ideal choice for any building.
Increased Ventilation
Clerestory roofs are great for promoting good ventilation inside your building if they are designed properly.
Designing these windows in the correct way will allow you to bring fresh air into your building for optimal ventilation.
Roof floors tend to generally have high levels of humidity. Clerestory windows can help let this moist air out of your building preventing mold and mildew growth.
Increased Energy Efficiency
If designed properly, clerestory roofs can help increase your building’s energy efficiency.
Windows for clerestory roofs should be strategically chosen so that they minimize heat loss in winter while also reducing heat gains during the summer.
Because an improper design and/or installation process can reverse the benefits of clerestory windows making more harm than good, it is essential to hire a professional expert who knows what they are doing.
Happier Occupants
As mentioned above, good lighting conditions can improve occupant comfort and well-being. This is the primary reason why clerestory windows are often added to buildings.
Cons of having clerestory roofs
Although clerestory roofs can provide many benefits, they may not be the best design feature for all types of buildings.
When deciding whether to install clerestories on your building or not it is critical that you consider all potential disadvantages as well before coming up with a final decision about this type of roofing system.
Increased Construction Costs
The main disadvantage of clerestory roofs is that they tend to be more expensive compared to other types of roofing designs.
While this may not be a big problem when designing new buildings, it may be a problem if you are trying to renovate an existing building.
Increased Energy Consumption (If not implemented well)
Another potential disadvantage of clerestory roofs is that they can increase your building’s energy consumption.
If the windows for this type of roof are not designed and installed properly, heat loss in winter and heat gains during summer can more than cancel out any benefits brought by increased natural light exposure.
Hence, you should always make sure to choose the right contractor when designing and installing clerestory windows.
Can you convert your existing roof into a clerestory roof?
You can convert your existing roof into a clerestory roof. However, this type of modification may be more difficult to implement than simply adding new windows on an already-built roof.
Because this process requires making several roof modifications, you should consider it as a last resort.
It is always better to start with the design of clerestory windows before converting your existing building into this type of construction.
This way you will be able to ensure that the process goes smoothly without any potential complications or setbacks later on down the road.
Therefore, if you would think it may be your next DIY project, then think again.
It is best to contact a professional roofing contractor who can help you with the conversion or installation of clerestory roofs in your structure.
Does it worth converting your existing roof to a clerestory roof?
This depends on the type of structure you have, as well as your current needs.
If you are just looking to bring more natural light into your building, then you may not need to build a new roof with clerestory windows. Instead, you can simply install skylights which will be significantly cheaper and easier to achieve.
However, if you design a building with clerestory roofs in mind, they may be worth it depending on how they are designed and installed.
How to care for your clerestory roof?
It is important to understand that clerestory roofs are not the same as traditional flat roofs.
Therefore, it is crucial to be careful when repairing or maintaining your roofing system and follow best practices whenever possible for this type of construction.
Clerestory windows are susceptible to leaks if maintenance is not performed regularly. This is because the water can get trapped in the small spaces between windows and lead to excessive damage at a later stage.
You should keep this in mind when designing clerestory roofs so you can avoid potential leaks after installation by making sure that proper maintenance is performed at least once every year.
The maintenance process for this type of roofing system usually involves cleaning, checking windows, replacing any cracked, broken, or damaged windows, and cleaning the roof surface.
Edges, where the windows are connected to the roof, should be checked as well to ensure water tightness.
These spots should be checked for any cracks, holes, or leaks and if any are found, they should be fixed immediately.
The sealant applied during the installation of these windows doesn’t last forever. It will eventually wear out, crack, or become detached from the roof surface.
Therefore, you should consider having your contractor seal it again after a certain period of time to make sure that water does not enter through these gaps and cause leaks inside your building.