Thermal insulation

Thermal Insulation - Thermal insulation refers to all measures taken to reduce heat transfer through a building’s envelope-including the facade, roof, basement ceiling, and windows. It reduces heating energy consumption, improves living comfort, and increases a property’s value. The Building Energy Act (GEG) prescribes minimum standards for thermal insulation in new buildings and when renovating major structural components.

Insulation Measures and Materials

The most important insulation measures: Facade insulation (ETICS with EPS, mineral wool, or wood fiber insulation boards; target U-value: 0.20-0.24 W/(m²·K); cost: 100-200 euros/m²). Roof insulation (above-rafter, between-rafter, or under-rafter insulation, target U-value: 0.20 W/(m²·K), cost: 50-200 euros/m²). Basement ceiling insulation (insulation boards installed from below, target U-value: 0.30 W/(m²·K), cost: 30-60 euros/m²). Window replacement (triple-pane glazing, U-value: 0.8-1.0 W/(m²·K), cost: 500-1,000 euros per window). Basement ceiling insulation offers the best cost-benefit ratio and often pays for itself in 3-5 years.

When choosing an insulation system, summer heat protection is also playing an increasingly important role. While lightweight insulation materials such as EPS provide good winter insulation, heavy materials such as wood fiber insulation boards store heat and release it gradually-this prevents overheating in the summer. For buildings in Nuremberg with south-facing facades or attic conversions, summer heat protection is particularly relevant, as the region is one of the warmest in Germany.

GEG Requirements and Funding

The GEG sets minimum requirements for insulation in new construction and renovations: If more than 10% of a building component is replaced, the GEG standard must be met. In addition, the government generously subsidizes thermal insulation measures: The BAFA subsidizes individual measures (facade, roof, windows) with 15-20% of the eligible costs. The KfW offers low-interest loans with a repayment subsidy for complete renovations to achieve an Efficiency House. A prerequisite is the involvement of a certified energy consultant who plans and certifies the project.

For owners who wish to renovate in several stages, the Individual Renovation Roadmap (iSFP) is particularly helpful: It outlines the optimal sequence of measures and secures an additional subsidy bonus of 5% for each measure implemented according to the iSFP. Important: Subsidy applications must be submitted before the start of construction work-submitting an application retroactively is not possible.

Thermal Insulation and Property Value

Good thermal insulation has a direct impact on a property’s market value. Buildings with high energy efficiency ratings (A, A+) typically command 5-15% higher purchase prices in the Nuremberg metropolitan region than comparable properties with poor energy ratings (F, G, H). With rising energy prices and stricter GEG requirements, thermal insulation is also becoming increasingly important as a measure to preserve value: Poorly insulated properties risk increasing depreciation, as buyers factor in future renovation costs.

Practical Tip for Property Owners in Nuremberg

We recommend that property owners in the Nuremberg metropolitan area planning an energy-efficient renovation start with an individual renovation roadmap (iSFP). The iSFP is prepared by an energy consultant, costs approximately 800-1,600 euros for single-family and two-family homes (80% of which is covered by BAFA funding), and outlines the optimal sequence of measures. Those who implement measures according to the iSFP receive an additional 5% funding bonus. There are numerous listed energy consultants in Nuremberg (dena expert list). The savings potential is enormous, especially in the widespread post-war buildings with uninsulated facades and single-pane windows (energy class G-H)-facade insulation can reduce heating energy demand by 30-40%.

We also recommend checking the current energy performance certificate before purchasing an existing property in Nuremberg and incorporating the modernization recommendations listed there into the purchase price negotiations. A building in energy class G or H will require significant investments in thermal insulation in the coming years-this should be reflected in the purchase price.

Frequently Asked Questions

How much can I save with thermal insulation?

The savings depend on the initial condition and the measure taken: Facade insulation saves approx. 20-35% of heating costs, roof insulation approx. 10-25%, window replacement approx. 10-15%, and basement ceiling insulation approx. 5-10%. For a comprehensively renovated single-family home in Nuremberg, heating costs can drop from 3,000-4,000 euros/year to 1,000-1,500 euros/year. The payback period is 10-20 years-subsidies can shorten this to 7-12 years.

Is facade insulation mandatory?

Retroactive facade insulation is not universally mandatory. The GEG requires compliance with minimum standards if more than 10% of the facade area is being renovated (so-called conditional requirement). If only a new coat of paint is applied without removing the existing plaster, there is no insulation requirement. In the event of a change of ownership, certain building components (top floor ceiling) must be insulated within 2 years if they do not meet the GEG standard.

Which insulation material is best?

There is no single best material-the choice depends on the application and requirements: EPS (Styrofoam) - affordable, good insulation performance, standard for ETICS. Mineral wool - non-combustible (fire protection class A), good sound insulation, versatile. Wood fiber insulation boards - eco-friendly, good summer heat protection, more expensive. PUR/PIR - highest insulation performance per cm (ideal when space is limited). Blown-in insulation (cellulose, mineral wool) - ideal for cavities and sloped ceilings. Ask an energy consultant to recommend the right material for your building.

Do I need a building permit for facade insulation?

Generally no - installing an ETICS is exempt from permitting requirements in most cases under the Bavarian Building Code (BayBO). Exceptions apply to historic buildings (permit from the State Office for the Preservation of Historical Monuments required), buildings in certain renovation zones, and in cases of setback issues (the insulation layer increases the exterior dimensions). Please clarify this in advance with the Building Regulations Office of the City of Nuremberg.

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