The inner space of the teahouse can be adjusted by means of sliding doors, opening up different levels of perception of the nearby landscape and framing various views like a painting in the interior. When the teahouse is closed, a gilded skylight provides a play of sunbeams in the interior. The whole interior is crowned by the knitted geometry of a cone soffit made of sisal ropes. The hearth is the centrepiece of the room, from which the space flows towards a large veranda made of larch planks. The veranda provides a unique space for looking out at the water and life below. Another important interior motif is a rounded wall with clay plaster, incorporating three bamboo vases reminiscent of the famous Japanese tokonoma – a niche for flowers and calligraphy.
The teahouse is designed to be a natural part of the landscape, with the green roof as a fragment of the grassy surroundings. The whole house is covered with charred larch cladding.
The Black Teahouse is on the southern edge of the garden and is reflected in the water of a small, dark lake. Its large and cultivated garden becomes a natural part of the nearby pine forest and its southern edge is bordered by an S-shaped lake with grassy banks. The teahouse is therefore part of the scenery and beautiful surroundings and affords a fabulous view of the lake. It is a place to gather and enjoy a cup of tea.