200 



LANDSCAPE DESIGN 



Retaining 

 Walls 



Terrace 

 Banks 



possible alternatives may be chosen is one of architectural detail 

 which we cannot cover here. 



The most definite and architectural form of terrace is produced by 

 a retaining wall crowned with a properly proportioned balustrade and 

 perhaps paneled with piers or buttresses. Especially where this wall 

 is not very high, the proportion between the wall and the parapet be- 

 comes a matter of great importance. If these proportions, as they are 

 forced upon the designer by the normal height of a balustrade and the 

 necessary difference in elevation of the ground, are not satisfactory, 

 they may be improved to some extent by a judicious choice of the height 

 of the base-course for the wall or of the crowning course on which the 

 base of the parapet is set. If no solid parapet and no stone balustrade 

 can be arranged in good proportion, it may still be possible to construct 

 a light iron grille-work which will serve all purposes of safety without 

 assuming importance in the design of the wall, and without intruding 

 on the view from the terrace itself. 



Where there is a possibility that a long straight run of terrace wall 

 may prove monotonous, it may be broken by projections which offer 

 particularly good viewpoints and which serve some subordinate pur- 

 pose of their own as objects in the design. The face of a terrace 

 wall is almost always broken by steps at some place, and indeed the 

 case seldom arises where the designer cannot obtain sufficient variety 

 of shape in a terrace by recognizing local requirements, and this with- 

 out appearing to have willfully distorted the shape of the structure. 

 A terrace wall is an ideal backing and protection for herbaceous 

 planting, as can be seen in many examples of the English borders. 



Where, for reasons of economy or design, it is undesirable to sup- 

 port a terrace by a vertical retaining wall, a sloping bank may be used 

 with its surface held in place by turf or possibly by other planting. If 

 the terrace is to retain its architectural character, some fine-textured 

 covering material like turf will be essential, in order that the surfaces 

 and lines of the bank may remain sufficiently defined. From the 

 practical point of view, the slope will be determined by the angle of 

 repose of the material and by the possibility of cutting the grass : a 

 slope steeper than forty-five degrees is likely to be hard to maintain.* 

 * Cf. Natural banks, Chapter VIII, p. 148. 



