SECTION 6 - MATERIALS
The specification of appropriate and approved materials ensures a building’s architectural integrity as well as its successful integration into the Loreto Bay village. It also minimizes the environmental impacts and ensures optimal occupant health. Environmental impacts are associated with the extraction, processing, and manufacture of building products.
6.2 Selection Criteria
Designers are encouraged to use products that are extracted, processed, and manufactured from local sources within 500 miles (800 km) of the house site, to reduce energy use by minimizing transportation requirements.
6.3 Reduce Environmental Impacts
Homeowners, designers, and builders are encouraged to favor natural materials and those with recycled content, low embodied energy, and carbon sequestering properties.
6.4 Indoor Environmental Quality
Builders are encouraged to increase occupant comfort and health by ensuring indoor air is free of odors, humidity, and chemical contaminants. Traditional materials such as stone and brick, with wood for detailing, are encouraged. Rock and brick should be exposed and artistically detailed. Concrete block and concrete may be used for courtyard walls and interior construction and finished with a smooth plaster to achieve a solid appearance. In all cases, plaster finish should be rounded at edges and corners.
Designers should prioritize natural products and, where required, use composite products with low or no volatile organic compounds. Alternatives include organic lime washes, clay plaster, milk paint, natural oils such as linseed, bees wax, tree resin, and other organic resources. Adhesives, sealants, primers, paints, and cleaners derived from raw materials which have low toxicity, are renewable, and involve low environmental footprint should be used where possible.
Use water-based products with no VOCs (volatile organic compounds) (Compuestos Orgánicos Volátiles -COVs) or less than 87 g/l (grams per liter) for exterior (such as Sherwin Williams Kem- Tone K25) and less than 56 g/l for interior (such as Sherwin Williams ProMar 400). Testing should be in accordance with Norma 123-Ecol-1998 SEMARNAT.
Water-based adhesives are generally better than solvent-based options. Green Seal’s adhesive standard sets 150 grams of volatile organic compounds (VOCs) per liter of product as a safe maximum. Low-toxicity, water-based adhesives contain latex or polyvinyl acetate. Natural adhesives contain plant resins in a citrus solvent or water dispersion system. Dry adhesives contain resins stored in capsules released by pressure. All of these adhesive groups have minimal hazardous emissions once installed.
Avoid conventional particle board and MDF for cabinetry. In addition to wood, alternatives include wood stalk wheatboard, a particleboard made from wheat straw, a waste product of farming bound together with a formaldehyde-free resin.
6.5 Types of Finish Materials
The following is a summary of the main finish materials that may be considered and how they are used in Loreto Bay.
• Exposed concrete may be considered as a finished surface. No form marks may be visible, including tie rod pockets.
• Concrete and exposed aggregate may be used.
• Cast concrete may be used for decorative elements such as window sills and lintels, columns, and capitals.
• Concrete floors may be treated by color or stamping.
• Concrete may be combined with stone in masonry assemblies.
• Specify 30-40% fly ash mix. This reduces the amount of cement, responsible
for greenhouse gas emissions, replacing it with a waste product that improves the strength of concrete over time.
• Polished and densified concrete floors combine diamond stone-polishing
technology with silicate chemical treatment to provide a significantly better alternative to film and wax coatings. They are highly durable, nearly maintenance free, and non-combustible. The improved reflectivity can also reduce lighting requirements.
• Coloring pigments or acid treatments in concrete add architectural interest, using very little additional material, and turning concrete into a finished surface, which avoids the need for additional products and coatings and eliminates the environmental impacts associated with manufacturing and maintaining those materials.
• Stone is encouraged as an exposed building and finishing material and may be used for walls, floors, pathways, columns, and detailing.
• Details may include stone sills and lintels, column bases and capitals, and wall
• Stone for exterior applications should be procured from local (Baja, Mexico) quarries.
• Stone walls must have a rough, split face, not a smooth, cut face.
• Stone applied to the structural wall must be no less than 6” in depth. At wall corners, stones should appear to be “structural” (one stone) and not appear as the thin veneer slabs that overlap at the corner.
• The use of recycled antique architectural stone is encouraged.
• Walls may have a combination of materials that include stone, i.e. stone and brick
• Pebbles may be used in mosaic or between brick courses.
• Fired clay brick may be used for wall bases, detailing elements, and as ceiling finish.
• Vaulted and arched brick ceilings are encouraged.
• Arches may be detailed in brick.
• Brick columns and arches are permitted, when detailed appropriately.
• Flattened and elongated bricks may be used, particularly for curved forms.
• Brick dimensions must be approved by the Design Review Committee.
• Terra cotta and brown brick colors are preferred over yellow clay brick.
• Plaster is the most common wall surface in Mexico, and its use is encouraged in Loreto Bay.
• Quality workmanship is expected.
• Plasterwork may be smooth or textured and should have softened corners.
• Crackalura plaster finish may be used for feature walls.
• Ceilings, domes, arches and window heads, corbels, and brackets may all be plaster.
• Distressed walls may be incorporated.
e) Clay Roofing Tile
• Clay tiled pitched roofs are one of the most significant architectural features of the Loreto Bay Village.
• Roofing tiles must be clay tiles; however, alternate roofing tile materials may be allowed so long as the material simulates the look of clay.
• Tile shapes, colors, and dimensions must have the approval of the Design Review Committee.
• Roof pitches must be appropriate for proper tile installation and detailing.
• Roofing tile must be properly installed to prevent excessive damage by high winds.
• The standard roof tile palette contained in the attached Appendix has been approved for use in Loreto Bay.
f) Pergola and Palapa Roofing
• Support must be with wood beams and posts. The use of rope lashings and exposed decorative fasteners is encouraged.
•Pergola roofing must be wood slatted, dowel, tile, or similar appropriate and approved materials. Fabric coverings must be appropriate and approved as to quality and color.
• Palapa roofing, made from shingled palm leaves, may be used to provide cost- effective shade and cooling; however, fire issues must be considered. Use of palapa is considered appropriate only for Village Edge homes and only on the beach or golf course side of the property.
• Shed-style and radius-style are most common, but ridge beams and posts may be used to support larger palapa roofs.
• Quality palapa workmanship creates longer lasting roofs.
• Heavy timber post and beam woodwork is common in Mexico and encouraged in Loreto Bay but wood is a limited resource and largely imported. It may be used for posts, beams, lintels, exposed stringers, and rafters.
• Rafter tail detailing and corbel bracket detailing is a local art form in Mexico and is encouraged.
• Column bases, shafts, capitals, and cornices are suitable for wood detailing.
• Visually textured wood doors and windows are a required feature of the Loreto Bay style.
h) Ceramic Tile
• Ceramic tile, including Saltillo and Talavera, are touchstones of Mexican architecture.
• Floors, walls, counters, window sills, soffits, ceilings, domes, fountains, showers, and a myriad of other architectural forms and elements may be tiled in Loreto Bay.
• Shaded tile floors are a natural cooling device.
• Tiled pools and fountains are wonderful architectural accents.
• Most of the red clay tile used in Loreto Bay is Mexican factory-made. These tiles are compressed by machine, fired, and often pre-sealed. This product is more durable than the hand-pressed process used in Saltillo tiles.
• Tile is an inherently low-toxic, waterproof, durable finish material for flooring, walls, and other applications. While tile is somewhat energy-intensive to manufacture, the materials involved are readily available and mined with fairly low impact. In addition to clay tile, consider products containing post-consumer or post-industrial recycled content, such as recycled glass tiles.
• Consider light-colored tile for exterior applications in order to reduce heat island effects.
• Ornamental ironwork is a reminder of Mexico’s European heritage and is generally Spanish, French or Moorish in its stylistic origins. Original artistic expression is encouraged within the accepted parameters of the Loreto Bay Style.
• Grillwork, fences, gates, railings, handrails, brackets, supports, balconies, light fixtures, hinges, door pulls and knockers, fasteners and features are all part of Mexican ironwork.
• Quality ironwork is required for buildings in Loreto Bay.
• No two houses facing each other in the same block may have the same ironwork design.