A stage-by-stage look at how a Sienna villa is built on the El Jamito slope: site prep, column foundations, concrete frame, flat roof slab, systems and finishes, and why each is done that way.
A hillside villa at Sienna goes up in six construction stages: site preparation, column foundations, the reinforced-concrete frame, a flat concrete roof slab, building systems, and finishes. Each stage is shaped by the slope of the El Jamito hills. The villa stands on columns instead of a cut-and-fill pad, and it gets a slab roof instead of sheet metal. For a pre-construction buyer, these stages are what your payment milestones are paying for.
The Short Version
- Building a home on a hillside starts with surveying, tree protection and as little earth-moving as possible. Concrete comes later.
- Column foundations step down the slope, so the villa doesn't need a large excavated platform held up by retaining walls.
- The frame is reinforced concrete columns and beams with block infill walls, which is the standard way concrete villas are built in the Dominican Republic.
- The flat concrete roof slab is poured as one piece. It resists wind uplift and gives solar panels a solid base.
- Systems go in before plaster and finishes go in last. That is why change requests cost less the earlier you make them.
What Are the Construction Stages of a Hillside Villa?
There are six stages, and each one has to be finished before the next can start. The order is fixed by physics, not paperwork. You can't pour a roof slab until the columns and beams below it have cured, and you can't plaster a wall until the conduits inside it are in place. This article covers what happens and why. For how long the whole purchase takes, see our reservation-to-title-deed timeline.
| Stage | What you see on site | Why it's done this way |
|---|---|---|
| 1. Site preparation | Survey stakes, fenced trees, access path, erosion barriers | Moves as little soil as possible and protects the canopy you want to keep |
| 2. Column foundations | Separate footings at different depths, rebar cages, columns rising | Follows the slope without a big excavated platform |
| 3. Concrete frame | Beams, floor slabs, block walls, window and door openings | Builds a rigid frame for loads and storm forces |
| 4. Roof slab | Formwork across the top, rebar mat, one continuous pour | Resists wind uplift and supports solar panels |
| 5. Systems | Pipes and conduits in wall chases, cistern, wastewater unit | Services must be buried before surfaces are closed |
| 6. Finishes | Render, earth-tone exterior, windows, tile, kitchen, native planting | Specified for humidity, salt air and the building guidelines |
The rest of this article goes through the stages in that order.
What Happens Before Any Concrete Is Poured?
The first stage is survey and protection, and it takes more planning than any later one. The villa's footprint is staked against the real contours of the lot, which sits in a band roughly 150-300 m above sea level. Trees worth keeping are marked and fenced, and a narrow access path is cut for materials.
Reading the ground first
Footing depths come from the ground itself, which is why the geotechnical work matters. It tells the engineer how deep each footing has to go to reach stable soil. On a slope, that depth can differ from one corner of the house to the other. If you're still choosing a lot, our guide to the geotechnical report for a hillside lot lists the questions to ask before you reserve.
Moving as little earth as possible
Erosion control goes in early: barriers downhill of the work area and routes that keep rainwater away from loose soil. Say your lot has a mature tree where the terrace was going to be. This is the stage where the terrace gets moved or cantilevered, not the stage where the tree comes down.
The takeaway: whatever you protect in stage 1 will still be there when you move in.
Why Use Column Foundations Instead of a Flat Pad?
On a slope, separate column footings disturb far less soil than a flat platform, so they protect roots, drainage and the shape of the hillside. The usual alternative is to cut into the hill, push the soil downhill as fill, and hold the result in place with retaining walls. That approach creates two weak points: fill that can settle, and walls that have to hold back water-soaked earth in every heavy rain.
How the columns step down the hill
With column foundations, each footing is dug only where a column will stand. Rebar cages go in, the footings are poured, and reinforced concrete columns rise from them. Uphill columns are short and downhill columns are taller, so the ground floor ends up level even though the land under it isn't. Grade beams tie the columns together so the structure works as one unit.
Rainwater can keep running downhill under the house, along the path it always took. Roots between the footings stay alive. We cover the engineering in more detail in building on a slope with column foundations.
On a hillside, the cheapest foundation to pour is rarely the cheapest foundation to own.
What Does Concrete Villa Construction in the Dominican Republic Look Like?
The standard method is a frame of reinforced concrete columns and beams, with walls of concrete block filling the spaces between them. Most new villas in the country are built this way, and Sienna uses the same method because local trades know it well and it holds up in storms.
Frame first, walls second
The columns and beams carry the loads. Rebar is tied inside wooden or metal formwork, checked, and then the concrete is poured. Before forms are stripped and the next level goes up, the concrete has to cure, and rushing that step is a common mistake. The block walls go in after the frame, with the window and door openings already placed for cross-ventilation and for the view. 28 of the 30 Zone 1 lots have ocean views.
What to verify at this stage
What should you ask for while the frame goes up? Ask for confirmation that the rebar was inspected before each pour, ask how curing was handled, and check that the openings match your approved plans. Openings can't be moved cheaply once the block walls are built around them.
Why Does a Sienna Villa Have a Flat Concrete Roof Slab?
A flat reinforced-concrete slab stands up to hurricane winds much better than lightweight sheet roofing, and it gives the villa a solid deck for solar panels. Sienna's building guidelines don't allow aluminum roofs. We explain why in this guide to tropical building materials.
How the roof slab is poured
Formwork and temporary props are set across the top of the frame. A mat of rebar is laid on top, and every conduit, drain outlet and roof penetration is placed before any concrete goes in. Ideally the slab is poured in one continuous session so there are no weak joints. After curing, the roof gets a waterproofing membrane, a slight slope toward the drains, and insulation or a heat-reflective top layer.
Why the roof matters for energy
Concrete holds heat, so without insulation a slab roof will warm the rooms below it at night. Getting the roof right affects more than comfort. According to the International Energy Agency, buildings account for roughly 30% of global final energy consumption, and much of a tropical home's energy goes into cooling. Sienna's infrastructure is solar-ready, and the slab is where the panels go, within the 40 cm roof cap set by the building guidelines.
When Do Systems and Finishes Go In?
Systems go in once the walls and roof are up, and finishes go in only after the systems are tested. Plumbing and electrical conduits are laid in channels cut into the block walls, and the wiring to the roof is prepared for solar. The rainwater cistern and the villa's own wastewater treatment unit are installed and connected. Internet comes by satellite (Starlink) or a local wireless provider, so the plan includes a place to mount the receiver and a route for its cable.
Finishes built for humidity and salt air
Then the surfaces close up. The walls are rendered, and the exterior is painted in an earth tone because white walls aren't permitted. Windows and doors are chosen to cope with humidity and salt air, then the tile, kitchen and bathrooms go in. Landscaping is done last and uses mostly native species: 70% of the planting at Sienna is native.
Want different finishes? Changes cost the least before the stage they affect. Moving a socket is easy before plastering and expensive afterwards. After this stage comes the handover inspection checklist.
What Are You Paying For at Each Milestone?
On a Sienna-built villa, each payment milestone corresponds to physical work you can check, and the owner portal reports milestones for your own villa. Knowing the stages lets you look at a site update and tell whether the work matches what you paid for. For example, you can see whether the foundations are poured and cured, or whether the slab is waterproofed.
Sienna-built vs self-build: the tax difference
Whoever builds the villa, the construction stages are the same. The tax treatment is not. Under Law 158-01, CONFOTUR exempts qualifying projects from the 3% transfer tax and the 1% annual IPI. Sienna holds provisional status under Resolution 203-2024, extended by Resolución 61-2026. The definitive classification was filed in July 2026 and is still pending, and the benefits take effect once it is issued. If that happens, the exemption covers what Sienna builds and delivers, and it applies only to the first buyer from the developer. If you buy a lot and build with your own contractor, you would be exempt on the land value only, and you stay taxable on rental income.
Following your build from abroad, in French
Las Terrenas has a large French-speaking community, including 1,200+ French-speaking Quebec residents, and many buyers want to follow their build in French. Sienna's team works in English, French, Spanish and German, so your milestone updates can be in your own language. The villa models and layouts page shows what each stage eventually produces.
Frequently Asked Questions
How long does each construction stage take?
It depends on the villa's size, the slope of the lot and the weather, so we don't give generic durations. Your contract sets out the schedule. The sequence in this article doesn't change, but the calendar can.
Can I change finishes after the frame is up?
Usually yes, but the cost goes up as the work moves forward. Changes that affect walls, plumbing or electrical routes are cheapest before the systems stage. Surface finishes can be changed later, up to handover.
Does a self-built villa follow the same stages?
Yes. Self-built plans still go through Sienna's design review against the building guidelines, including the column-foundation approach, the 40 cm roof cap and the earth-tone exteriors. The difference is CONFOTUR scope: the exemption covers the land value only, not the villa.
Is a concrete hillside villa safe in a hurricane?
No building is storm-proof. Still, a reinforced-concrete frame and roof slab on a site 150-300 m above sea level, well away from coastal surge, is a much stronger starting point than lightweight construction on the shoreline.
The Bottom Line
A Sienna villa goes up in a fixed order of site prep, columns, frame, roof slab, systems and finishes, and each stage is shaped by the slope. If you know what each stage looks like, you can check every milestone you pay for. To go through the build sequence for a specific lot or floor plan, book a no-pressure consultation with our team.
Have questions about this?
Talk to our sales team directly — we'll answer on WhatsApp or by phone.
Written by
Sienna Terrenas Editorial Team
The Sienna Terrenas editorial team covers buying, owning, and living in Las Terrenas, Dominican Republic — from the purchase process and CONFOTUR tax strategy to villa construction and Caribbean community life, drawing on the team's on-the-ground experience in the area. Meet the Sienna Terrenas team.
