Heat pump housing for housing an outdoor unit of a heat pump heating a building, wherein the outdoor unit comprises an air input opening and an air output opening; and wherein the heat pump housing comprises: - a rectangular cuboid-shaped section comprising: - an installation surface for installing the outdoor unit, wherein the installation surface is arranged on an inside of the building; - a wedge-shaped section comprising: - an air inlet grille arranged for allowing air outside of the building to flow towards the outdoor unit; and - an air outlet grille arranged for allowing air to flow from the outdoor unit to the outside of the building; - an inlet channel for fluidly coupling the air inlet grille and the air input opening; and - an outlet channel for fluidly coupling the air outlet grille and the air output opening; wherein the air inlet grille and/or the air outlet grille are arranged to a slanted roof of the building; and wherein the rectangular cuboid-shaped section and the wedge-shaped section are produced as separate parts; characterized in that either the inlet channel or the outlet channel is an outer channel; and that the other of the inlet channel or the outlet channel is an inner channel; and wherein the outer channel envelops the inner channel. wherein the outdoor unit comprises an air input opening and an air output opening; and wherein the heat pump housing comprises: - a rectangular cuboid-shaped section comprising: - an installation surface for installing the outdoor unit, wherein the installation surface is arranged on an inside of the building; - a wedge-shaped section comprising: - an air inlet grille arranged for allowing air outside of the building to flow towards the outdoor unit; and - an air outlet grille arranged for allowing air to flow from the outdoor unit to the outside of the building; - an inlet channel for fluidly coupling the air inlet grille and the air input opening; and - an outlet channel for fluidly coupling the air outlet grille and the air output opening; - a rectangular cuboid-shaped section comprising: - an installation surface for installing the outdoor unit, wherein the installation surface is arranged on an inside of the building; - an installation surface for installing the outdoor unit, wherein the installation surface is arranged on an inside of the building; - a wedge-shaped section comprising: - an air inlet grille arranged for allowing air outside of the building to flow towards the outdoor unit; and - an air outlet grille arranged for allowing air to flow from the outdoor unit to the outside of the building; - an air inlet grille arranged for allowing air outside of the building to flow towards the outdoor unit; and - an air outlet grille arranged for allowing air to flow from the outdoor unit to the outside of the building; - an inlet channel for fluidly coupling the air inlet grille and the air input opening; and - an outlet channel for fluidly coupling the air outlet grille and the air output opening; wherein the air inlet grille and/or the air outlet grille are arranged to a slanted roof of the building; and wherein the rectangular cuboid-shaped section and the wedge-shaped section are produced as separate parts; characterized in that either the inlet channel or the outlet channel is an outer channel; and that the other of the inlet channel or the outlet channel is an inner channel; and wherein the outer channel envelops the inner channel.