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14.11.2025

Internal sun shading vs. external: which is better?

Q: What is the difference between internal and external sun shading?

Internal sun shading systems are located in the interior. External solar shading is fitted to the façade or window and stops the sun's rays in front of the glass. The latter are significantly more effective at protecting against heat and contribute to energy efficiency.

Q: Which solar shading solution is eligible?

Only external systems such as Roller Shutters, External Venetian Blinds or Textile Screens are eligible for subsidies. ROMA supports you with the BAFA subsidy helper to quickly check your eligibility.

Q: How do I find the right sun shading for my home?

The choice depends on the structural conditions, design requirements and technical equipment. ROMA specialist partners will advise you individually and help with planning, selection and implementation.

Woman in dining room with External Venetian Blinds in front of the window

Internal sun shading is often installed as a quick solution against heat and prying eyes from outside. However, when choosing a sun shading system, you should always think long-term: Is internal solar shading sufficient to keep rooms at a comfortable temperature throughout the year? Anyone planning for the long term should be fully aware of the differences between internal and external sun shading systems such as Roller Shutters, External Venetian Blinds or Textile Screens. After all, the right sun shading not only regulates the indoor climate, but also ensures greater comfort.

As experienced experts, our ROMA specialist partners are on hand to help you plan and choose the right sun shading system.

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Internal sun shading vs. external: the most important facts in brief

Internal sun shading: sits in front of the window on the room side.
External sun shading: is fitted from the outside in front of the window or with the window.
Both variants: protect against glare, unwanted glances and UV rays.
Advantage of external sun protection: effective heat protection and insulation.
Subsidies: only external thermal insulation is eligible for subsidies.

What is internal sun shading?

Internal sun protection for windows refers to shading systems that are fitted on the inside of the room. These include pleated blinds, roller blinds, Venetianblinds and panel and vertical blinds.

Internal sun protection systems are particularly suitable if you are looking for a quick solution. They are usually easy to install and can be replaced flexibly. It is often possible to attach the sun protection to the window without drilling using clamp brackets or adhesive strips.

Sun enters through the window and hits the internal sun protection

Internal sun shading: quick installation and flexible design

Internal sun shading systems are particularly impressive due to their high level of flexibility. Quick installation means that the systems can be replaced at any time if required. In addition, internal sun shading offers a wide range of options for harmonious interior design.

However, the solar shading effect of internal systems is limited, especially in the hot summer months. As the sun's rays are only stopped behind the window, the unprotected room directly behind the window heats up anyway. The resulting heat can spread almost unhindered from there into the room.

Internal sun shading: advantages at a glance

Internal systems do not offer strong thermal insulation in summer. Nevertheless, they have various advantages:

Simple retrofitting without structural changes
Quick installation
Protection against glare and prying eyes
Individual light regulation
Can be controlledmanually, electrically or sometimes via Smart Homesystems
Wide range of designs for the interior

What is external sun shading?

External sun protection is installed on the outside in front of the window. These include Roller Shutters, External Venetian Blinds and Textile Screens. These systems can be used to completely shade buildings. Textile Screens also make it possible to protect the home from the sun while maintaining a view to the outside.

Although this sun protection is installed on the façade, it can be conveniently controlled from the inside - manually controlled, electrically at the touch of a button or with a Smart Home system. External sun shading also offers a wide range of design options. The color matching to the façade creates a harmonious overall look and combines functionality and design.

Discover the ROMA color harmony now

Man walks in front of half-closed External Venetian Blinds from ROMA

External sun shading: long-term solution for greater energy efficiency

External solar shading systems stop the sun's rays before they reach the window pane. In the warm summer months, this is a particularly effective way of regulating heat build-up in the interior. They can be installed in both new and existing buildings. Depending on the system, no major structural measures need to be taken for installation.

Thanks to the high insulating effect of external systems such as Roller Shutters, they also help to regulate the heat in the interior in winter. This increases the energy efficiency of the entire building.

Energy-efficient renovation of windows

External sun shading: advantages at a glance

In addition to strong heat protection, external sun shading offers numerous other advantages:

Eligible for subsidies for energy-efficient refurbishment (e.g. via BAFA)
Protects against glare, UV radiation and prying eyes
Individual light regulation with a view to the outside
Contributesto thermal insulation in summer and increases energy efficiency
Can be controlled manually, at the touch of a button or via ROMA Smart Home
Reinforces burglar resistance

Secure subsidies for external sun shading

Only external solar shading is subsidized by the state - for example via the BAFA subsidy as part of the Federal Subsidy for Efficient Buildings (BEG). As a rule, structural measures that contribute to summer heat insulation and meet certain technical requirements of the BAFA are eligible for funding. You can check whether your measure is eligible for funding in just a few minutes with the free ROMA funding assistant.

Check funding options now

Comparison of external and internal sun shading

In addition to protection from the sun and heat, various factors can play a role in choosing the right sun shading system. Which criteria make the decisive difference depends on individual needs and requirements.

Criterion

Internal

External

External advantage

Heat protection

good

Very good

Glare protection

good

Very good

Privacy screen

good

Very good

Burglary protection

No protection

Very good

Thermal insulation

low

good

Energy efficiency

low

Very good

Smart Home integration

sometimes possible

Frequently possible

Retrofittability

Very simple

Dependent on structural conditions

Eligibility

Not eligible

Possible via BAFA

Year-round heat regulation with external solar shading systems

External sun shading systems such as ROMA Roller Shutters, external Venetian blinds and vertical awnings make a significant contribution to year-round climate control: in summer they block the heat, in winter they insulate and reduce heat loss. Particularly with automated control, comfort and energy efficiency can be increased at the same time - for example through automated or weather-based opening and closing times.

Advice from an experienced ROMA specialist partner is an advantage when planning a suitable sun shading system.

Find a ROMA Distributor

Frequently asked questions (FAQ) about external and internal sun shading

What is the difference between internal and external sun shading?

Internal sun shading systems are located in the interior. External solar shading is fitted to the façade or window and stops the sun's rays in front of the glass. The latter are significantly more effective at protecting against heat and contribute to energy efficiency.

When is internal sun shading useful?

Although the thermal insulation of internal systems is lower, they still protect against prying eyes and unpleasant light. They are an ideal addition to external sun shading or as an alternative where structural possibilities are limited.

Which solar shading solution is eligible?

Only external systems such as Roller Shutters, External Venetian Blinds or Textile Screens are eligible for subsidies. ROMA supports you with the BAFA subsidy helper to quickly check your eligibility.

Can external sun shading be retrofitted?

Yes, many external systems can also be installed in existing buildings - such as ROMA Front-Mounted External Venetian Blinds, Front-Mounted Roller Shutters or Front-Mounted Textile Screens. The choice of sun shading system is also flexible for retrofitting.

How do I find the right sun shading for my home?

The choice depends on the structural conditions, design requirements and technical equipment. ROMA specialist partners will advise you individually and help with planning, selection and implementation.

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