On top of an existing 1950s holiday home, hidden in the forest, a sculptural, compact and sustainable rooftop extension climbs out of the original structure and seeks it’s way towards the great vista over the open grassland enclosed by the forest. The extension is situated within the leaves and feels like a secluded tree house. The design fits the restrictions stated by the municipality concerning maximum height and sloping roofs. The existing house is refurbished in a sustainable way based on full autarky. A new off-grid solar system provides in energy. A wood-stove provides in warmth and wastewater that now ends up in a septic tank, will be filtered by a halophyte filter in the near future. The rooftop extension is almost entirely constructed out of timber, with flax insulation and all facades and roofing are covered with untreated Larch cladding. Hanging stairs in the existing living room provides access towards the new compact extension. The exterior and interior of the extension are tailor fit designed for the functions and usage. The beds and storage space are built-in so no further furniture will be needed. The rooftop extension offers space for two bedrooms and a landing with a wash table, which provides access towards the existing roof. The existing roof was already frequently being used as a secret place to enjoy the setting sun and the flora and fauna.