When we started building Montserrat Reserve, we made a commitment to use natural building materials for the tropics wherever the land and the climate allowed it. That decision shaped everything — the timeline, the budget, the relationships we built with local craftspeople, and the character of the finished villas. It also taught us lessons that no textbook or supplier catalog could have prepared us for. This is what we learned, material by material, about building naturally on the Oaxacan coast.
Parota Wood: The Backbone of Every Structure
Parota (Enterolobium cyclocarpum), also called guanacaste or elephant ear tree, became the primary structural wood for the entire project. It was not our first choice on paper — we had considered imported teak and ipe early in the design phase — but once we understood what parota could do, there was no real alternative.
Properties and Performance
Parota is a tropical hardwood native to the Pacific coast of Mexico and Central America. The heartwood is dense, with a Janka hardness around 470 lbf, which places it in a middle range — hard enough for structural beams and posts, soft enough to work with hand tools when needed. The grain is interlocked and often figured, producing the wide, sweeping patterns that make parota furniture so sought after. But for us, the structural qualities mattered more than the aesthetics.
The wood is naturally resistant to termites and boring insects, which is not a luxury feature on the Oaxacan coast — it is a survival requirement. We have seen conventional lumber destroyed within two years by drywood termites in this climate. Parota’s natural oils and density make it inhospitable to the insects that would eat softer woods alive. It also handles moisture well. The cellular structure does not absorb and release water as dramatically as many tropical species, which means less warping, less cracking, and fewer surprises as the seasons shift between bone-dry and monsoon.
Sourcing and Ethics
We sourced all of our parota from trees that had already fallen or were removed from agricultural land within a 60-kilometer radius. None of it came from standing forest. This matters, because parota trees can live 200 years or more, and cutting a living one for construction lumber felt wrong for a project built around sustainability. The downside of sourcing fallen wood is unpredictability — you take what is available, not what you ordered. Logs arrived in different sizes, different moisture contents, different conditions. Some had insect galleries that had to be cut around. Others had spalting patterns that were beautiful but signaled early decay.
We dried the wood naturally, stacking it with spacers in a covered area with good airflow, for four to six months depending on thickness. Kiln drying would have been faster — a week or two — but natural drying produces a more dimensionally stable product for this climate. The wood acclimates to the actual humidity it will live in, rather than being shocked dry and then reabsorbing moisture once installed. We lost roughly 15 percent of our lumber to checking and splitting during the drying process, which is a real cost. You need to order more than you think you need.
Aging and Patina
Fresh parota heartwood is a warm reddish-brown. Over the first year of exposure to sun and air, it shifts to a golden amber, then gradually to a silvery grey on surfaces that receive direct UV. The weathered grey is not decay — it is a surface patina, similar to what happens with cedar or teak, and the wood beneath remains sound. Some of our villas have beams that are now two-toned: golden brown on the sheltered side, silver on the sun-facing side. We think it is beautiful, but guests sometimes ask if the wood is “old.” It is not old. It is alive to its environment, and it shows.
Cost Compared to Imported Hardwoods
Parota cost us roughly 40 percent less than imported teak and 55 percent less than ipe, even accounting for the higher waste percentage from natural sourcing and drying. The savings came not just from the wood itself but from the logistics — no international shipping, no customs, no import duties, no fumigation certificates. A farmer with a flatbed truck delivered it. That said, the labor to sort, dry, cut around defects, and hand-finish parota takes longer than working with graded, kiln-dried import lumber. The total installed cost was still lower, but the margin was smaller than the raw material price suggested.
What We Would Do Differently
We would start the sourcing and drying process a full year before construction, not six months. We underestimated how long natural drying takes during the rainy season, when ambient humidity hovers above 80 percent and the wood simply will not cure. We would also invest in a moisture meter from day one rather than relying on the tap-and-listen method, which our carpenters swore by but which was not reliable enough for structural members.
Clay Plaster: Walls That Breathe
Clay plaster covers the interior and some exterior walls of every villa at the reserve. It is one of the most satisfying materials we used — and also one of the most demanding.
Humidity Management
The Oaxacan coast has two modes: the dry season (November through May), when humidity drops to 50 or 60 percent, and the rainy season (June through October), when it climbs above 85 percent daily and stays there. Most wall finishes fight this — sealed paint traps moisture, gypsum plaster absorbs it and stays damp, cement stucco cracks as it expands and contracts.
Clay plaster does something different. It absorbs excess humidity from the air when conditions are wet and releases it when conditions are dry, functioning as a passive humidity buffer. In practical terms, the interior of a clay-plastered villa feels noticeably more comfortable during the rainy season than a conventionally finished room. Not air-conditioned-comfortable — naturally-comfortable, which is what we were after.
Application Technique
Our plaster is a mix of local clay, river sand, and chopped straw fiber applied in three coats over a cane-and-mesh substrate. The first coat (the scratch coat) is thick, rough, and keyed into the substrate. The second coat levels the surface. The finish coat is the finest — strained clay mixed with fine sand, applied thin and burnished with a smooth stone or a plastic trowel to compress the surface.
Timing matters more than technique. You cannot apply clay plaster during the height of the rainy season because it will not cure — it just sits there, wet and soft, inviting mold. You also cannot apply it during the driest, hottest weeks because it dries too fast and cracks before it bonds. The sweet spot is the shoulder seasons: late October or early May, when the air is warm but not saturated. We learned this the hard way after losing an entire wall during a July application attempt.
Pigments and Color
The color of our plaster comes from the clay itself. Different clay deposits in the region produce different tones — from pale cream to deep terracotta to a cool grey with blue undertones. We blended clays from three sources to arrive at the warm, earthy tone we wanted. No synthetic pigments, no paint. The color goes all the way through the plaster, which means scratches and chips do not reveal a different color underneath — they just reveal more of the same material.
Maintenance
Clay plaster is not maintenance-free. During the first dry season after application, hairline cracks will appear as the plaster completes its curing. These are normal and cosmetic. We fill them with a slurry of the same clay mix, rubbed in with a damp cloth. Every two to three years, exterior clay surfaces need a fresh skim coat to replace material lost to rain erosion. Interior surfaces last much longer — we expect five to seven years between refinishing.
What We Would Do Differently
We would apply a silicate-based sealer to exterior clay surfaces in areas with direct rain exposure. We resisted sealers initially because we wanted fully breathable walls, but the erosion rate on west-facing walls (which take the brunt of the rainy season storms) was higher than we expected. A breathable silicate sealer would reduce erosion without eliminating the humidity-buffering quality.
Local Stone: The Foundation of Everything
Stone from the property and surrounding area forms the foundations, pool surround, terraces, pathways, and retaining walls throughout the reserve.
Foundation Work
We used irregularly shaped basalt and limestone for all foundation walls, dry-stacked where loads allowed and mortared with lime-based mortar where structural integrity demanded it. Lime mortar, not Portland cement — lime stays slightly flexible as it cures, which accommodates the minor ground movement that happens during the rainy season on this terrain. Rigid cement mortar cracks. Lime mortar breathes, flexes, and can even self-heal hairline fractures as dissolved lime recrystallizes in the presence of water.
Working with Irregular Shapes
Every stone is unique. There are no standard dimensions, no pallets of uniform blocks, no coursed rows. The masons who built our foundations are artists in the truest sense — they select each stone by eye, rotate it, test its fit against its neighbors, and set it with a tap of the hammer that sounds like it means something. The work is slow. A skilled mason and helper laid roughly two linear meters of foundation wall per day. A concrete crew could have formed and poured the same length in two hours.
The result, though, is a foundation that looks like it grew out of the bedrock. The colors vary — dark grey basalt next to cream-streaked limestone next to rust-colored ironstone. The textures change. The surfaces are alive in a way that poured concrete never is.
Thermal Mass
Stone walls absorb heat during the day and release it slowly at night. On the coast, where daytime temperatures regularly hit 34 degrees Celsius and nights drop to 22 or 23, this thermal mass effect is significant. The stone foundations and lower walls keep the interior of each villa cooler during the afternoon heat and slightly warmer during the pre-dawn hours. It is not a replacement for good ventilation design, but it is a powerful complement to it.
What We Would Do Differently
We would budget more time. Stone masonry took roughly three times longer than we estimated, and the labor cost reflected that. We would also source a larger initial stockpile before beginning — we ran out of suitable stone twice during construction and had to pause while more was collected and transported. Having a full supply on site before the masons begin would have eliminated those delays.
Palm Thatch and Palapa Roofing
The palapa — a roof structure made from dried palm fronds over a wooden frame — is the defining architectural element of coastal Oaxacan building. We used traditional palapa construction on three of our five villas, with terracotta tile on the other two.
Waterproofing
A properly thatched palm roof is remarkably waterproof. The fronds are layered in overlapping courses from eave to ridge, with each layer covering the stems of the layer below. Water runs down the surface of the fronds and drips off the eaves without penetrating. The key word is “properly” — a badly thatched roof leaks within the first season. We hired thatchers from a family in the Chacahua lagoon communities who have been building palapas for three generations. Their technique involves specific frond selection (mature, fully dried, from the right palm species), specific overlap ratios, and a ridge cap method using woven fronds that we have not seen described in any written source. It is handed-down knowledge, and it works.
Lifespan and Replacement
A well-built palm roof lasts seven to ten years on this coast before it needs full replacement. The degradation is gradual — you lose density over time as individual fronds decay, and eventually the roof thins to the point where light (and then water) starts coming through. We plan for full re-thatching on a rotating schedule, one villa at a time, so the entire property is never under construction simultaneously. The old palm material goes straight into the compost system.
Between full replacements, spot repairs are needed every year or two — patching areas where wind has lifted fronds, replacing sections damaged by falling branches, reinforcing the ridge cap after storm season. This is ongoing maintenance, not a one-time installation. If you are not prepared for that, use a different roofing material.
Ventilation Benefits
A palm roof breathes. Hot air rises through the thatch and escapes through the ridge, creating a passive chimney effect that moves air continuously through the villa. On a still, hot afternoon, you can feel the air moving upward inside a palapa-roofed room even when there is no breeze outside. This is the single most effective passive cooling feature in our entire design — more impactful than the clay walls, the stone thermal mass, or the cross-ventilation windows. The combination of all four is what makes the villas comfortable without air conditioning, but if we had to choose only one, it would be the thatch roof.
Fire Treatment
Palm thatch is combustible, and fire is a real risk. We treat the thatch with a borate-based fire retardant applied as a spray during installation. Borates are mineral-derived, low-toxicity, and also provide additional insect resistance. The treatment does not make the roof fireproof, but it raises the ignition temperature significantly and slows flame spread enough to allow evacuation and response. We reapply the treatment every three years. We also maintain strict fire safety protocols on the property — no open flames inside or near the villas, dedicated fire extinguishers at each structure, and cleared vegetation buffers around every building.
What We Would Do Differently
We would install a secondary waterproof membrane beneath the thatch on all palapa roofs. We did this on one villa as an experiment and the membrane — a breathable, UV-resistant synthetic sheet — added a failsafe layer that we now wish we had everywhere. It does not affect the ventilation or the aesthetics (it is invisible from below), but it catches any water that penetrates the thatch during an unusually heavy storm or as the thatch ages and thins.
Terracotta Tiles: Regional Craft, Reliable Performance
Two of our villas use terracotta tile roofing sourced from a family-operated kiln about 45 kilometers inland.
Thermal Performance
Terracotta tiles have moderate thermal mass — less than stone but more than metal or synthetic roofing. They absorb solar heat during the day and re-radiate it in the evening. The key is the air gap: traditional barrel tiles create small channels between each course, and air moves through these channels via convection, carrying heat away from the interior. The underside of a terracotta roof is noticeably cooler than the top surface, which means the radiant heat load on the rooms below is significantly reduced compared to flat metal roofing.
Regional Kilns
The tiles we use are handmade — formed over curved wooden molds, dried in the sun for several days, then fired in a wood-burning kiln at temperatures around 1,000 degrees Celsius. Each tile is slightly different in color, shape, and thickness. The variation is part of the character. Machine-made tiles are more uniform but lack the tonal richness of hand-fired clay, which ranges from deep burnt orange to pale salmon depending on its position in the kiln.
The relationship with the kiln family matters. They understand what we need, they know the clay source (a deposit they have been mining for decades), and they fire the tiles hard enough for coastal conditions — under-fired terracotta absorbs too much water and spalls during freeze-thaw cycles or, in our case, during rapid temperature changes between a hot day and a cool rain.
What We Would Do Differently
We would order 20 percent more tiles than the calculated quantity. Handmade tiles have a breakage rate during transport and installation that is higher than factory products. We ran short twice and had to wait for a new kiln firing, which added weeks to the roofing schedule.
Bamboo: The Material We Used Sparingly
Bamboo is often presented as the ultimate sustainable building material — fast-growing, strong, versatile. We used it, but less than most people expect, and for specific, limited applications: shade structures, garden trellises, interior shelving, and decorative screens. Not for primary structure.
Structural Limitations in Coastal Salt Air
The Oaxacan coast is a harsh environment for bamboo. Salt air accelerates the degradation of the silica-rich outer layer that gives bamboo its structural strength. Within two to three years of coastal exposure, untreated bamboo begins to lose surface integrity — the outer skin flakes, moisture penetrates, and fungal decay follows. Treated bamboo (typically borax-soaked) lasts longer, but the treatment needs to penetrate fully, which is difficult with larger-diameter culms.
We tested bamboo structural posts in a non-critical application — a garden pergola — during the first year of construction. After 18 months, two of the six posts showed visible cracking and early fungal colonization at the base, where ground moisture met salt-laden air. The posts were still structurally sound, but the trajectory was clear. We replaced them with parota and moved bamboo to non-structural, easily replaceable applications where its lightweight and aesthetic qualities shine without carrying loads.
What We Would Do Differently
We would not change our approach. Bamboo is excellent in the right context — inland, protected from salt, in applications where replacement every few years is acceptable. On the coast, for permanent structures, parota and stone are simply better choices. We would, however, experiment more with bamboo for temporary and seasonal structures — pop-up shade canopies, event structures, garden infrastructure — where the shorter lifespan is a feature rather than a flaw.
The Bigger Lesson
Building with natural materials in the tropics is not about nostalgia or ideology. It is a practical decision rooted in climate, geography, and the long-term performance of the building. Every material we chose — parota, clay, stone, palm, terracotta — has been used on this coast for centuries because it works here. The industrial alternatives — concrete block, steel stud, synthetic stucco, galvanized roofing — work too, but they work despite the climate rather than with it. They fight the heat, the humidity, the insects, the salt. Natural materials negotiate with those forces. They absorb, release, flex, breathe, and age in ways that synthetic materials cannot.
The cost is patience. Natural materials demand more time to source, more skill to install, more attention to maintain. They do not arrive on a pallet in standard dimensions ready to assemble. They arrive on the back of a truck, irregular and alive, and they ask you to pay attention to what they are before you decide what they should become.
We think that attention — that slowness, that care — shows up in the finished space. When you step into one of our villas, the walls are not uniform, the beams are not identical, the stone floor has a texture that changes under your feet. These are not imperfections. They are evidence that human hands built this place out of the earth it sits on, and that the earth had a say in how it turned out.
That is what building with natural materials means to us. Not a style. Not a trend. A conversation with the land, conducted through the materials it provides, resulting in a place that belongs exactly where it is.
If you want to see what this looks like in person — to sleep under a palm roof, to run your hand along a clay wall, to feel the cool of a stone floor on a hot afternoon — Montserrat Reserve is opening in 2027. We would love to show you what we built.