Whole plant

DGfdB guideline R 65.10 fixes the order for refurbishments: 1) reduce losses (envelope, pool cover, insulate the surge tank, ventilation heat recovery), 2) recover heat (heat recovery, waste-water heat, filter backwash as a heat-pump source), 3) generate efficiently (heat pump > CHP > gas). This hierarchy is decisive for public grant applications: funders check whether losses were reduced before the generation investment. Concretely: insulate the surge tank, add an outdoor-pool night cover and service the ventilation heat recovery before or together with the heat-pump installation.

Basis: DGfdB R 65.10

Mandatory rules for a public family pool: DIN 19643 (water treatment) — hygiene duty, annual sampling. VDI 2089 (ventilation) — recommended, not enforced, but an insurance standard. DIN 1946-4 — ventilation hygiene duty, inspection every 2 years. GEG 2024 — energy certificate on refurbishment, air-conditioning inspection every 4 years. Occupational safety — annual electrical test. An energy audit per DIN EN 16247 is advisable for municipalities with more than 250 staff (not compulsory for a small operator).

Basis: Synthesis DIN/VDI/DGfdB

The German Buildings Energy Act GEG 2024 treats pools as non-residential buildings. Mandatory air-conditioning inspection every 4 years (ventilation > 12 kW). On change of ownership or major refurbishment, tighter envelope U-values apply (external wall U ≤ 0.24 W/(m²·K)). A demand-based energy certificate is required above 250 m² of heated floor area. A hall pool with 1,800 m² of envelope at U=0.8 does not meet new-build standards — so grant funding for envelope refurbishment (up to 35 % rate) is available.

Basis: GEG 2024 (German Buildings Energy Act)

The ISEK programme co-funds municipal climate-protection and refurbishment measures at 50 %, capped at 500,000 € per measure and 5 M€ per project. Precondition: the measure is anchored in the municipal climate-protection plan. Processing takes 6-12 months. Measures can be bundled (e.g. heat pump + insulation + load management in one application) but cannot be combined with federal BAFA funding on the same asset. Note: PV car-port roofing is usually funded separately at 30 %; ISEK eligibility for PV is a case-by-case decision requiring a climate-protection rationale.

Basis: ISEK (German regional urban-development grant)

The federal Module 2 funds heat pumps, thermal storage and heat-network connections in non-residential buildings at 40 %. Important: it is NOT combinable with the regional ISEK grant on the same measure. Municipalities must choose: ISEK 50 % (higher rate, longer processing) or the federal 40 % (faster, nationwide). ISEK is usually the better choice when the climate rationale holds; the federal grant is a fallback if ISEK is refused.

Basis: Federal efficient-energy grant, Module 2