A house built in 1970 carries decades of modifications, material wear, and outdated systems. The rehabilitation of a single-story residence in the Las Condes district of Santiago demonstrates how systematic intervention can transform a tired post-war structure into a contemporary home that meets modern energy and comfort standards. Part of a set of 25 houses originally designed by architects Christian de Groote, Victor Gubbins, and Hector Mery, this 130-square-meter project used reinforced masonry, slab, and reinforced concrete beams — construction methods common to the era. The renovation strategy focused on removing ad-hoc modifications, upgrading the thermal envelope, and reconnecting interior spaces with the surrounding gardens. This approach aligns with passive house design for warm climates where opening a building to natural ventilation and daylight takes priority over sealing it tight against cold weather.
Assessing the Existing Structure in 1970s Residential Construction
The first step in any rehabilitation project is understanding what the existing building offers and what needs removal. In this case, the original house had accumulated light frame extensions and material additions over five decades that showed clear signs of wear and did not match the original construction quality. The design team eliminated all these modifications before planning any new work.
Reinforced Masonry and Concrete Beam Construction
The original structure used reinforced masonry walls topped with a concrete slab and reinforced concrete beams — a system common in South American residential construction from the 1960s and 1970s. This type of construction offers good compressive strength and durability but limited flexibility for reconfiguration. Load-bearing masonry walls cannot be removed without alternative support, so any new openings must be carefully planned with lintels or moment frames to redistribute loads. The rehabilitation maintained the same construction logic for all new surface area, extending the existing reinforced masonry and concrete beam system rather than switching to a different structural typology. Projects like the modern barnhouse vision demonstrate similar principles of respecting original structural systems while adapting them for contemporary use.
Identifying and Removing Non-Original Additions
A systematic survey of the property identified several categories of non-original work:
- Light frame extensions to the service area with incompatible materials and detailing
- Enclosed sections of the original courtyard that blocked natural light paths
- Surface-applied finishes covering original concrete masonry with paint and tile that had deteriorated
- Plumbing and electrical runs surface-mounted through interior spaces during previous renovations
Removing these additions revealed the original spatial organization and allowed the design team to plan interventions that respected the building’s structural logic while meeting the needs of a family with three children.
Opening Perimeter Walls for Courtyard Views and Natural Light
The original 1970 layout arranged 25 houses so that each one adjoined its neighbors, sharing dividing walls that consolidated an intermediate walled yard. Each house had a garden to the north and another to the south — a land-efficient arrangement typical of planned communities from that period. But over time, modifications had closed off the visual and physical connections between interior rooms and these gardens.
The rehabilitation strategy proposed opening perimeter walls to integrate the views of the courtyards. This involved cutting new openings in the reinforced masonry walls, framing them with concrete lintels, and installing full-height glazing where previously there were solid walls or narrow windows. The existing skylight was enhanced, and a new light well was introduced to bring deeper daylight penetration into the center of the floor plan.
The Chimney Removal and Floating Wall Replacement
One of the more significant interventions was removing the original chimney, which occupied a central position and blocked visual flow between the living and dining zones. In its place, the design team introduced a floating concrete wall that performs two functions simultaneously: it separates the living area from the dining space while also functioning as a shelf for display and storage. This floating element does not extend to the ceiling, preserving sightlines and light flow across the upper portion of the room while defining distinct zones at ground level.
Adding Light Yards and Skylights
The service area was completely rebuilt to incorporate two light yards and a new skylight on its roof. These light yards follow the same logic as the existing ones — small, open-to-sky spaces that channel daylight and natural ventilation into the interior. The new skylight uses the same geometry and orientation as the original, creating a consistent vocabulary of roof openings across the renovated house.
| Intervention Type | Original Condition | Rehabilitation Solution | Light Improvement |
|---|---|---|---|
| Perimeter walls | Solid masonry with narrow openings | Full-height glazed openings with concrete lintels | 60 to 80 percent more daylight in adjacent rooms |
| Chimney location | Central masonry structure blocking sightlines | Floating concrete wall shelf | Unobstructed upper-level light flow |
| Service area | Dark, enclosed rear addition | Two new light yards plus roof skylight | Consistent daylight in previously dark zone |
| Existing skylight | Single small roof opening | Enhanced size and glazing area | Deeper daylight penetration to center of plan |
Upgrading Windows With Thermopanel Glazing
The renovation called for thermopanel crystals in all openings — essentially double-glazed units with a sealed air gap between two panes of glass. Thermopanel windows provide a substantial improvement over the original single-glazed units common in 1970s residential construction. The window selection for the farmhouse in similar renovation projects shows how choosing the right glazing can transform both thermal performance and occupant comfort.
Performance Comparison: Single vs. Double Glazing
| Parameter | Single Glazing (1970s original) | Thermopanel Double Glazing | Improvement |
|---|---|---|---|
| U-value (W/m²K) | 5.7 to 5.8 | 2.7 to 3.0 | 48 to 53 percent better |
| Sound reduction (dB) | 25 to 27 | 33 to 38 | 6 to 13 dB reduction |
| Condensation resistance | Poor — frequent internal condensation | Good — warm inner pane surface | Eliminates most interior condensation |
| Winter heat loss | High — primary thermal weak point | Moderate — sealed air gap slows heat transfer | 40 to 50 percent less heat loss |
The thermopanel units specified for this project also incorporate low-emissivity coatings that reflect infrared heat back into the room while transmitting visible light. This technology was not available during the original 1970 construction and represents one of the largest single improvements available for showcase homes that inspire real-world design retrofits.
Modern Heating Systems: Aerothermal Heat Pumps and Radiant Slabs
The entire heating system was replaced as part of the rehabilitation. The original system — likely a gas boiler with radiators — was removed and replaced with a high-efficiency aerothermal heat pump paired with a radiant slab system. Aerothermal technology extracts heat from outside air using a refrigeration cycle, achieving efficiencies that far exceed combustion-based heating.
How Aerothermal Heat Pumps Work in Residential Applications
An aerothermal heat pump captures thermal energy from ambient air even when outdoor temperatures drop below freezing. The system uses a compressor and refrigerant loop to concentrate this energy and transfer it to a water circuit that feeds the radiant slab. In cooling mode, the cycle reverses to extract heat from the interior and discharge it outside. The coefficient of performance (COP) for modern aerothermal units ranges from 3.0 to 4.5, meaning they deliver three to four and a half units of heat for every unit of electricity consumed.
Radiant Slab System Benefits
Complementing the heating upgrade, the bedroom sector received a new bathroom added to serve a family with three children. The exterior wall at the bedroom wing was modified by releasing it from the main structure and building a structural element that hangs separated from the facade. This hanging wall element creates greater spaciousness inside the bedrooms while improving privacy and brightness — a detail that parallels the passive house design and construction lessons where envelope improvements double as spatial enhancements.
Material Palette: Honoring Original Structure With Contemporary Additions
The predominant materials used in this rehabilitation are wood, stone, glass, steel, and exposed concrete. The design team deliberately chose materials that put the original structure in value while adding a contemporary language that integrates vegetation into the overall composition.
Exposed Concrete, Wood, and Stone in Practice
The existing concrete structure was cleaned rather than covered. Adding a new curved wall of exposed concrete at the street entrance reconfigures the approach to the house, guiding visitors from the gate to the front door. This curved element also defines the new parking area and barbecue zone on the north side of the property. The floating concrete wall inside the house — the chimney replacement — demonstrates how a single structural element can organize an entire floor plan. Wood appears primarily in the form of a timber deck in the intermediate courtyard, chosen to give warmth and permanence to the outdoor seating area. The remaining palette stays restrained: stone for select wall cladding, glass for the new openings, and steel for railings and structural brackets.
| Material | Location in Project | Function | Relationship to Original Structure |
|---|---|---|---|
| Exposed concrete | Curved entrance wall, floating interior wall | Spatial definition and circulation guidance | Matches original concrete beam aesthetic |
| Wood | Intermediate courtyard deck | Warmth and permanence for outdoor seating | Contrasts with original masonry |
| Stone | Selected wall cladding | Texture and connection to garden | Complementary to exposed concrete |
| Glass | All new openings, skylights | Daylight admission and courtyard views | Enables visual connection to original gardens |
| Steel | Structural brackets and railings | Support and safety | Minimal visual weight against heavy masonry |
Courtyard Consolidation for Fluid Indoor-Outdoor Living
The consolidation of three courtyards creates a fluid journey through the property at a single level. Before the renovation, these outdoor spaces were disconnected — the north garden was visually separate from the south garden, and the intermediate walled yard functioned as a service area rather than a living space. The rehabilitation unified these three zones into a continuous sequence of outdoor rooms that flow into the interior through the new glazed openings.
The intermediate courtyard received a wooden deck that extends the living area outdoors during warmer months. The barbecue area near the new concrete entrance wall allows the family to entertain without tracking through the main house. Each courtyard maintains a distinct character — the north garden for morning sun, the south garden for afternoon shade, and the intermediate deck as the social hub — while remaining visually connected to the interior through the extensive new glazing. This holistic approach to passive house remodeling demonstrates how courtyard-focused renovation strategies can improve both thermal performance and quality of life in existing residential fabric.