Sun protection

Sun protection encompasses all structural and technical measures that protect a property from excessive sunlight-ranging from external blinds and sun-protective glass to architectural elements such as loggias or canopies. Effective sun protection improves living comfort, reduces cooling energy requirements, and protects flooring and furniture from UV damage. In the context of energy efficiency, this topic is becoming increasingly relevant for property valuation and subsidy programs.

Architectural and Technical Sun Protection Systems

A basic distinction is made between external and internal sun protection. External systems-roller shutters, external blinds, awnings, and venetian blinds-are significantly more effective because they block heat before it enters the building. Internal sun protection, such as curtains or pleated blinds, prevents glare but allows heat to enter.

Sun protection glazing (g-value ≤ 0.35) offers a middle ground but is particularly disadvantageous during the heating season because it also reduces solar heat gains. For new construction and renovations, the Building Energy Act (GEG) mandates sun protection measures in certain situations-particularly when large south-facing glazing is planned and the cooling load exceeds the permissible limit. The GEG requirements are considered a minimum standard; higher-quality sun protection is subsidized through various KfW programs.

Efficiency and Energy Efficiency

The quality of a sun protection system is indicated by the reduction factor (fc): It describes how much of the incident solar energy is reduced by the sun protection. External venetian blinds achieve fc values of 0.10 to 0.25-meaning 75 to 90% of solar heat is blocked. Interior curtains only achieve fc values of 0.55 to 0.75-meaning a reduction of just 25 to 45%. For summer comfort in residential buildings, exterior sun protection is therefore indispensable, especially for south- and west-facing windows as well as skylights.

Sun Protection and Condominium Law

In condominium complexes, the installation of sun protection systems on the exterior facade is legally complex. Exterior blinds or awnings are considered structural alterations to common property and generally require a resolution by the condominium owners’ association (WEG). Since the 2020 WEG reform, however, such an installation can be approved by a simple majority. Anyone acting on their own initiative risks claims for removal. Tenants also require the landlord’s consent.

For WEG properties, we recommend addressing the topic of sun protection collectively at the owners’ meeting and defining uniform systems for all units. Uniform external blinds on the exterior facade create a high-quality visual appearance and enhance the building’s overall impression-which has a positive impact on the rentability and marketability of individual units.

Sun Protection as a Value and Marketing Feature

High-quality sun protection systems-particularly motorized exterior blinds or electric awnings-are increasingly becoming a quality feature on the Nuremberg real estate market that buyers and tenants expect. South-facing apartments without adequate sun protection can tend to overheat in the summer, which is viewed critically during marketing. The property listing should therefore explicitly mention existing sun protection-specifying the system (external venetian blinds, roller shutters, awnings), the control type (manual or motorized), and the window areas covered.

Practical Tip for Property Owners in Nuremberg and Franconia

Summer days in Nuremberg can be very uncomfortable with temperatures exceeding 35 °C-especially in attic apartments and south-facing units in neighborhoods such as Gartenstadt, Langwasser, or Nuremberg’s Südstadt. Anyone looking to sell or rent their property should keep existing sun protection systems in good condition and document them in the property listing. Outdated or defective roller shutters are a common shortcoming that immediately stands out during a viewing and increases the buyer’s room for negotiation.

For condominium associations (WEG), it’s worth checking the minutes of the most recent owners’ meeting: Often, resolutions regarding standardized sun protection systems that are binding for all units already exist. Installing non-compliant systems on one’s own initiative may result in an obligation to remove them. For attic apartments with skylights, we recommend interior shading systems with heat protection that are specifically designed for roof windows and can reduce the room temperature by up to 5 °C.

Frequently Asked Questions

As a homeowner, can I simply install an awning?

No - installing an awning on the exterior facade constitutes a structural alteration to the common property. You need a majority vote from the homeowners’ association meeting. Since the 2020 homeowners’ association reform, a simple majority is sufficient; however, a single owner cannot decide alone. Contact us - we’ll explain the process and help you prepare the resolution proposal.

Does solar control glazing count as a full replacement for exterior blinds?

Only to a limited extent. Solar control glazing prevents overheating, but it also reduces solar heat gain in the winter. For optimal comfort and energy efficiency, energy consultants usually recommend a combination of energy-efficient glazing and external, controllable sun protection. For new construction, this combination is a requirement for a higher subsidy tier in many funding programs.

How much does it cost to retrofit exterior blinds?

Costs vary significantly depending on the system, window size, and building structure. Simple exterior blinds start at around €400 to €600 per window, including installation; electric venetian blinds with smart home connectivity can cost €1,000 to €1,800 per window. For a building with eight windows to be fitted, a total investment of €5,000 to €15,000 is therefore to be expected-an investment that generally pays for itself through lower air conditioning costs and increased rentability.

Are there subsidy programs for the installation of sun protection systems?

Yes, exterior sun protection is eligible for funding under the Federal Subsidy Program for Efficient Buildings (BEG) if it is implemented in combination with other energy-efficiency measures (e.g., thermal insulation glazing, wall insulation). For single-family homes and owner-occupied apartments, the BEG individual measure subsidy may be considered if the sunshade is part of an energy-efficiency renovation package and an energy efficiency expert is involved. In addition, KfW offers low-interest loans for individual measures through the “Energy-Efficient Renovation - Supplementary Loan” program. In Bavaria, there are also the subsidy programs of the Bavarian State Ministry of Economic Affairs (BayWarmPlus), which also include properties in the Nuremberg metropolitan region. We recommend checking the funding options before hiring a contractor-it is not possible to apply for funding retroactively.

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