Energy-Efficient Renovation of Residential Buildings in Germany: EPBD, GEG and the Material List

Germany has about 19 million residential buildings, most built before the first thermal insulation ordinance of 1977. The recast Energy Performance of Buildings Directive adopted in 2024 and the national Gebäudeenergiegesetz (GEG) together set the framework for upgrading them. This article summarises the legal requirements as they stand in autumn 2026 and turns them into the material list a developer or contractor needs when planning the energy-efficient renovation of residential buildings in Germany.

Energy-efficient renovation of residential buildings in Germany: what the law requires

EPBD 2024

Directive (EU) 2024/1275 requires each member state to reduce the average primary energy use of its residential building stock by at least 16 % by 2030 and by 20 to 22 % by 2035 compared with 2020, with more than half of the reduction coming from the worst-performing buildings. New buildings must be zero-emission from 2030, public buildings from 2028. Member states must adopt national building renovation plans, introduce renovation passports and phase out financial incentives for stand-alone fossil-fuel boilers from 2025. The transposition deadline was 29 May 2026. The directive obliges the state, not the individual owner, to deliver the trajectory.

GEG

The GEG, in the version in force since 1 January 2024, contains the rules an owner actually meets on site. Three groups matter for renovation. First, component requirements in Annex 7: when an exterior wall, roof, floor or window of an existing building is renovated or replaced, the new component must not exceed a maximum U-value, for example 0.24 W/(m²·K) for exterior walls and pitched roofs, 1.3 W/(m²·K) for windows and 0.30 W/(m²·K) for floors against unheated space or ground. Second, unconditional duties: uninsulated accessible top-floor ceilings must be insulated and heating pipes in unheated rooms lagged. Third, the heating rule: a newly installed heating system must use at least 65 % renewable energy; in new-build areas since 2024, in existing buildings once the municipal heat plan is in place, with deadlines of mid-2026 for large cities and mid-2028 for smaller municipalities. Existing boilers may keep running and be repaired.

Rule: the GEG tells you the U-value the component must reach; it does not tell you how. The material list follows from the construction the architect chooses to reach that value, not from the law.

From U-value to material

A solid brick or concrete wall of a 1960s block typically has a U-value well above 1 W/(m²·K). Reaching 0.24 requires an external thermal insulation composite system (ETICS) with roughly 14 to 18 cm of insulation at a conductivity of 0.032 to 0.040 W/(m·K), or a ventilated facade with similar mineral wool. Pitched roofs reach the same value with rafter insulation; flat roofs with PIR or EPS boards under a new membrane. Windows achieve Uw 1.3 with double or triple glazing in uPVC, timber or aluminium frames. The heating side adds a heat pump, often with larger radiators, a hot water cylinder and a photovoltaic array.

The material list for an apartment block

Cement and reinforcing steel appear in almost every renovation, even though they are not energy measures: a heat pump needs a foundation, balconies that are thermally decoupled are often rebuilt, basement slabs are insulated and recast, and lift shafts added for accessibility need concrete and S355 steel. On larger estates these quantities justify buying on commodity terms with mill certificates rather than from the builders’ merchant.

Funding and sequencing

The federal funding programme for efficient buildings (BEG) supports individual measures through BAFA grants and whole-house standards through KfW loans with repayment bonuses; the heating replacement under the GEG has its own subsidy track within the BEG. Funding rules change frequently and must be checked before contracts are signed. Technically, the envelope should be upgraded before the heat pump is sized, because a lower heat load allows a smaller unit and lower flow temperatures. If the boiler fails first, the heat pump should be sized for the future, insulated building.

Checklist for the buyer of materials

1. Obtain the energy consultant’s calculation with the target U-values per component and the heat load after renovation.
2. Translate each component into a construction with a declared thermal conductivity and thickness, and require declarations of performance under the Construction Products Regulation.
3. Group commodity items (cement, rebar, structural steel, copper, aluminium profiles) into one procurement package with mill certificates to EN 10204 3.1.
4. Check the funding guideline for product requirements, for example minimum efficiency of the heat pump or certified ETICS systems.
5. Plan deliveries around scaffolding time, the largest avoidable cost on a facade renovation.

The directive sets the trajectory, the GEG sets the component values and the material list turns both into a building that costs less to heat.