Fireplaces opening onto an enclosed porch or paved terrace, are often built as an integral part of the house chimney (fig. 41). The corner of boundary walls permits effective treatment. Such fireplaces should meet the regulations of local fire authorities and be built with the same care and be subject to the same rules as inside fireplaces. OBTAINING PLANS Plans for outdoor fireplaces are available from various publishing houses; several magazines feature illustrations that can be adapted to the material at hand. If a structure is to be built with local labor and material, simple designs are advisable. The size of stones, joints, and proportions have a direct influence upon appearance, and good personal taste frequently results in more pleasing structures than blind adherence to conventional designs. The various combinations of ovens, cranes, grilles, storage compartments, benches, lights, sinks, etc., to be used as built-in features affect the design. Before planning a structure with these features, catalogs of dealers in outdoor fireplace equipment should be consulted for sizes of the available accessories so that ample space and proper details can be provided in the masonry for building them in. Skilled labor should be employed for elaborate designs (fig. 42) when much equipment is built in or when the fireplace, as in figure 41, is an integral part of a permanent building. [Illustration: Figure 42.--This fireplace, set at a focal point in the garden, enhances the landscape. It was built by a skilled mason.] CONSTRUCTION Ordinarily the fire is built on the hearth, no grate being used. Fire regulations in hazardous localities may require firing doors, dampers, spark screens, and a solid-plate cooking surface; otherwise these features are not essential. Two and a half square feet of cooking surface is desirable, while access to both sides and the end permit several people to cook at the same time. The side walls should have fairly level tops for pots and pans. Side walls are made 2 to 6 inches higher than the cooking level to permit anchoring the grille; if too high, they interfere with cooking. Commercial grilles are available, but satisfactory ones can be made of ½-inch to ¾-inch pipe or 5/8-inch reinforcing rods. The pipes should be 6 to 10 inches longer than the width of the firebox; they should be spaced not more than 1¼ inches apart and have their tops exactly level to prevent pots and pans from wobbling. Two or three pipes can be used for a lintel over the opening into the flue if regular iron lintels are not available. Where a solid top is desired, it should be of boiler plate at least ¼-inch thick. Such plates must be stiffened to prevent buckling by alternate heating and cooling; for ordinary purposes they are merely set on top of the grid though they may be hinged at the rear so they can be tipped back against the chimney.