Residence cum office, Kassel, Germany A combined residence/office building was built in 1992 within a residential suburb of Kassel, Germany, that built according to ecological standards. All main rooms as well as a bathroom and the winter garden are covered with earthen domes. The entrance is covered by three jack vaults built of green bricks, as explained in chapter 14. The central lobby is covered by a dome with a clear span of 5.2 m and a clear height of 4.6 m, which is provided with a skylight consisting of a double-layered acrylic glass dome. Leading off from this lobby are four additional domed rooms. Each room has the same span, with a clear height of 4 m, and each is provided with a central skylight and one window at normal height. The construction of these five domes was carried out using the rotational guide described in chapter 14. Though the central dome springs from a height of 1.75 m, and the domes of the four other rooms at heights of 0.75 m, no ring beam is necessary, the structure being designed so that all resultant forces fall within the middle third of the foundations. The domes in the bathroom and winter garden are formed over an irregular hexagon, and were built using a technique derived from the Afghan dome technique (see chapter 14) using arches inclined at angles of 40-60° from the horizontal. The eye-shaped opening remaining once the two sets of arches reach the point at which they converge is covered by changing the pattern of arches by 90°. All domes are covered with an additional layer of 20 cm rock wool for thermal insulation and sealed with a 2-mm-thick, hot-air welded reinforced plastic membrane, which is waterproof and ‘root-proof’. This is covered with 15 cm of earth, which acts as substrate for the frost-resistant and drought-resistant wild grasses. The single-storeyed house has a floor area of 216 m2, including the winter garden. Walls, shelves and sanitary objects are cov153
Residences