"You can easily check whether your planned exterior sunshade is eligible for a government grant using the ROMA Grant Assistant —BAFA grants are available, particularly for energy-efficient renovations."
Tobias Löhner, Head of Marketing
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25.06.2026
Which exterior sunshade is right for your project?
External sun protection shields rooms more effectively from overheating than any internal solution—because it blocks the sun’s rays before they reach the glass. But which sun protection system is right for which building? Whether Roller Shutters, External Venetian Blinds, or Textile Screens—the differences between the systems are greater than they appear at first glance. The following guide shows which systems are available and which criteria really matter when making a selection.
Are you interested in exterior sun protection?
Table of contents
External Sun Protection: The Most Important Points at a Glance
External sun protection is significantly more effective than internal sun protection because it reflects heat radiation before it reaches the glass.
Roller Shutters provide complete blackout and additional features such as burglary protection and noise reduction.
External Venetian Blinds allow for continuous light control while providing heat protection.
Textile Screens (vertical awnings) filter sunlight, reduce glare, and allow a view to the outside—even when the screen is closed.
For renovation and new construction projects, various installation methods and drive options are available, some of which qualify for government subsidies.
Basic principle: Keep heat out before it gets inside
The key advantage of exterior systems lies in the physics: a significant portion of the solar radiation that strikes a glass pane is transferred into the interior of the room as heat. Exterior sun protection interrupts this transfer before it occurs. Solar heat gain —measured in technical terms as the g-value—can thus be reduced to a fraction of its original amount. This has a direct impact on cooling requirements and the indoor climate.
This basic principle applies to all three main system families: Roller Shutters, External Venetian Blinds, and Textile Screens. What distinguishes them from one another are their function, appearance, installation method, and the level of construction work required.
Comparison of Textile Screens, External Venetian Blinds, and Roller Shutters
Roller Shutters: Complete Control Over Light and Heat
Roller Shutters are the oldest and most widely used system of exterior sun protection in Germany. When closed, the Roller Shutter Profiles roll tightly together and seal off the window almost completely. This allows for nearly complete blackout, noise reduction, and—with the appropriate roller shutter curtain —additional burglary resistance.
For whom are Roller Shutters the right choice?
Roller Shutters are particularly well-suited for bedrooms, children’s rooms, and any space where light blocking is needed. They are available as Front-Mounted Roller Shutters, Top-Mounted Roller Shutters, or Angled Roller Shutters, making them suitable for both new construction and retrofitting existing buildings —in many cases without having to replace the windows.
Electric or solar-powered RollerShutters can also be integrated into Smart Home systems and controlled automatically: on a schedule, based on weather conditions, or via an app.
External Venetian Blinds: Highly Efficient Light Control
External Venetian Blinds— also known as exterior blinds in specialty stores—feature swiveling aluminum slats whose angle can be adjusted continuously. This enables something no other system can achieve in this way: precise control over how much direct sunlight enters the room and at what angle.
When the external Venetian Blind Slats are positioned vertically, daylight enters the interior almost unimpeded. At a shallow angle, the slats reflect direct sunlight but still allow diffuse sky light to pass through. When fully closed, they effectively block out all incoming light.
What to Keep in Mind When Choosing External Venetian Blinds
External Venetian Blinds are more sensitive to wind than Roller Shutters. In wind-exposed locations, it is recommended to use a wind sensor that automatically retracts the system when the wind becomes too strong, thereby preventing damage to the slats. Wind limits vary depending on the size of the unit and the type of slats—this should be taken into account early in the planning process.
Textile Screens: Light Filters That Allow a View Through
Textile Screens— also known as vertical awnings—are made of technical fabrics that filter sunlight rather than blocking it. What makes them special is that, depending on the fabric chosen, the view to the outside remains unobstructed even when the screen is closed, while glare and heat gain are significantly reduced.
Textile Screens are ideal for rooms where a natural atmosphere should be maintained despite active sun protection: living rooms with panoramic windows, offices with large glass surfaces, or sunrooms.
Fabric Properties at a Glance
The openness factor of a textile screen fabric describes how much light passes through the material. Typical values range from 1% to 10%. Fabrics with an openness factor of nearly 0% offer maximum heat protection and privacy from the outside at night—however, during the day, it is not possible to see outside. If visibility is a priority, you should choose a fabric with a higher openness factor—and factor this aspect into your planning early on.
Still not sure which exterior sunshade is right for you?
If you’re not yet sure which system is right for your situation, you can use the ROMA Product Navigator as a first step. This online tool guides you through the most important decision-making criteria in just a few steps —from usage requirements and the facade configuration to your preferred operating method—and suggests the right system based on this information.
The Product Navigator is not a substitute for personal expert advice, but it offers structured guidance for anyone who would like to get an initial overview before their consultation.
Retrofitting Existing Buildings: What Matters
Anyone who wants to retrofit exterior sun protection without making major changes to the windows or facade faces some practical questions:
How much space is available above the window for the box?
Are there existing connections for electric motors?
Should you opt for solar-powered sun protection?
All three system families can generally be retrofitted. Front-mounted systems are installed directly in front of the window without interfering with the building structure. Solar-powered versions of Roller Shutters, External Venetian Blinds, and Textile Screens require no electrical installation at all—the solar panel on the box powers the motor independently.
External sun protection is not a standard choice
Roller Shutters, External Venetian Blinds, and Textile Screens are not interchangeable alternatives—they meet different needs, and the best choice always depends on the specific project. What all three have in common is that, as exterior sun protection, they can significantly reduce heat gain in the summer, save energy, and improve the indoor climate in the long term.
A good first step to get started is the ROMA Product Navigator —it helps you sort through your specific requirements and provides an initial system recommendation. For final consultation, planning, and professional installation, a qualified ROMA Distributor near you is available to assist you.
Frequently Asked Questions (FAQ) About Exterior Sun Protection
Is exterior sun protection really more effective than interior sun protection?
Yes, exterior systems are significantly more effective. They reflect the sun’s rays before they pass through the glass. Interior sun protection, on the other hand, only partially blocks the heat that has already been transferred through the glass into the room. For effective heat protection in the summer, energy consultants and the current GEG classification system therefore primarily recommend exterior solutions.
Can Roller Shutters, External Venetian Blinds, and Textile Screens be retrofitted to existing buildings?
All system families are available as front-mount systems and can generally be retrofitted to existing structures, provided that the structural conditions—particularly the space available for the housing—allow for it. In many cases, solar-powered drives make retrofitting external sun protection systems even easier, since no new electrical installation is required.
Solar Sun Protection from ROMA
Which system is eligible for government funding?
Exterior sun protection systems may be eligible for funding through the Federal Office for Economic Affairs and Export Control (BAFA) as part of energy-efficiency retrofit measures —this includes Roller Shutters, External Venetian Blinds, and Textile Screens, provided they meet certain energy efficiency requirements. You can check whether your project is eligible for funding using the ROMA Funding Assistant at .
How do I figure out which system is right for my home?
The ROMA Product Navigator provides the quickest overview: This online tool asks specific questions about usage requirements, the facade configuration, and ease of use, and uses this information to generate an initial system recommendation. The next step is to schedule a personal consultation with a ROMA specialist partner.
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