Additional features for new construction if you want to heat with gas?

Hello to the building community

For a planned new build (single-story on slab, solid 36.5cm with gable roof, living space approx. 110sqm, 2 people) the question of all questions.

Which features do I need in addition to a gas condensing boiler (new development area is connected to gas) to meet the Energy Saving Ordinance 2016 and KFW 55

Best regards Portoalere

Insulation everywhere under the slab at the wall and in the roof otherwise maybe also a central controlled residential ventilation with heat recovery that should be enough if the stone and the windows don't have underground values

Insulation everywhere under the slab, on the wall, and in the roof; otherwise maybe a central controlled residential ventilation with heat recovery, that should be enough if the stone and the windows don't have underground values

For Kfw 55 with gas?

36.5 cm walls (possibly even monolithic?) and then trying to achieve [gas kfw 55]? That won't be easy. Controlled residential ventilation with heat recovery will be necessary and a lot of m² of solar thermal to make the numbers look better. It certainly won't make financial or energetic sense...

Hello,

for the consultation, design, and calculation of a KfW 55 house, you must involve an energy consultant (energy efficiency list). To achieve a KfW 55 house, targeted building physics and technical system measures must be implemented, regardless of the technology or energy carriers used. In addition to the high insulation standard already required by the Energy Saving Ordinance 2016, close attention must be paid to the thermal bridge verification during implementation, as there is often untapped potential here. In a second step, the system technology must be chosen. Besides a gas condensing boiler, controlled residential ventilation with heat recovery and possibly solar are standard. An alternative viable option is a gas heat pump, which may make additional measures like heat recovery unnecessary, but alone currently still triggers high investment costs. Therefore, consultation with an energy consultant, the planner, is important!

Best regards, Erik