tion of 'shape' and texture. At these relatively low heights the ceiling can exert a considerable influence on sound control.
The usual way of treating the ceiling is to construct it of perforated sound absorbent material - employing a large cellular grid if acoustic and/or lighting considerations demand it. The depth of the cell form used will de- pend to a great extent on the height available, but it can be anything from 12ft. to 24ft.
Armstrong 'Minaform' is a possible solution providing cell depth of either 12ft. or 24ft. but not between.
Some of the German installations treat their furniture specially, provid- ing cabinets, lockers, cupboards and movable screens with perforated sound absorbent backings. But it is clear that this attenuation exercise can be over- done. Silence and its preservation can be inhibiting; the accidental creation of noise in quiet rooms comes as a jar- ring intrusion.
engineers as the justification for imper- fections that are caused by bad design and inadequate budgets.
Glazing and sun shading
The whole concept of the land- scaped office demands a new look at the role of the window. If the pro- vision of working illumination is not to be its role and geography and geometry deny this then what is?
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The Americans boldly opt for the almost window-less solution, leaving the glazing as mere vertical vision slits, the same height as the room and 18in. or so wide. The Germans have tended to persist with windows extending over the whole wall leaving ontrol of over the whole wall leaving ontrol of sun and sky to such aids as the louver blind.
Experience seems to indicate that success is more likely to come from the American approach; disappointing features of some otherwise splendid examples of landscaped offices in Munich, Hamburg and Dortmund have The need for a modicum of back- been excessive solar gain and sky glare. ground noise has been received with In Britain the suggested propor- open arms by some air conditioning tions of the glazed area are for not less
than 15 per cent, of wall area (with 30 per cent as a suggested optimum) and not less than one-sixteenth of floor area. These figures seem to give the necessary modelling while providing effective screening.
Recent American experience seems to show that the role of the window as a visual link with the outside world can be overstated; where sizeable windows with louverdrape blinds have been provided the blinds are seldom drawn back.
Having got the window, what comes through it can be controlled in a variety of ways. As has already been mentioned louver blinds either of the conventional, horizontal, or the newer vertical type can be used. To be effec- tive they have to be operated en masse
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some German installations have motor-driven control of the blind along each complete wall. To really keep out the heat the blinds need to be outside the windows, when of course maintenance becomes quite a severe problem.
There are various types of actual glazing that can be used to achieve the
Office of Osram GMBH, Munich, showing the expansive landscaped treatment. Lighting is by 2 and 3 lamp troffers set into the suspend- ed ceiling and providing more than 1000 lux on the working plane. Lighting fittings provide extract for the air; air input is via linear grids between the ceiling panels.
Far East BUILDER, December 1970
View of the first floor of the Orrestein and Koppel building at Dortmund. Lighting is by bare fluorescent lamps above a large section acoustic louver. Illumination at the working plane is about 1000 lux.
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