Finnish architects have long understood how to build homes that work with harsh northern climates while maximizing livable space. The Matchbox Houses in Espoo, Finland, designed by Avanto Architects Ltd, demonstrate how compact detached houses can achieve both privacy and openness on a single plot. These twin homes, completed in 2019, pack 360 square meters of gross area per unit into forms that read as modest volumes. The design principles behind them apply well beyond Finland, especially for builders and homeowners exploring passive solar design vs sun tempered houses approaches to energy-efficient layout.
The Matchbox Concept: Stacked Volumes for Privacy and Views
The name “Matchbox Houses” comes from the way the buildings appear as simple rectangular boxes placed on the landscape. Each house consists of two shifted volumes stacked on top of one another. The upper floor overhangs the lower floor on one side, creating a covered terrace below and a roof terrace above. This volumetric shift serves three purposes at once: it provides shade for the ground-level terrace, creates a sunny outdoor space on the roof of the lower section, and breaks up the massing so the houses feel less imposing on the site.
The site slopes gently toward the sea near Espoo, with the street bordering the north side. Existing stone fences, rocks, and pine trees provided a temporal perspective that the architects preserved. The two houses sit close enough to form a visual pair but are positioned to give each one privacy and the best possible views toward the water. Private clients commissioned the project, which moved from design in 2016-2017 through construction from 2017 to 2019.
Site Planning and Orientation
The surrounding buildings represent the architecture of single-family homes typical to Finnish suburbs, but the Matchbox Houses depart from convention in their siting. Rather than dropping a single large mass in the center of the lot, the architects split the program into two distinct forms that frame views and outdoor spaces. The lower volumes extend toward the sea view, while the upper volumes sit back, creating layered sightlines from both levels. This approach relates closely to how tight houses and moisture problems are managed through careful envelope design in northern climates.
Structural System: Load-Bearing Durability
The houses use a dual structural system combining in-situ cast concrete with a warm oak wood core. The load-bearing structures are designed to last longer than typical wood-frame construction. Concrete provides thermal mass that stabilizes indoor temperatures, while the oak core introduces warmth and texture to interior spaces. This combination of materials mirrors what builders have discovered through houses design case straw bale houses and other natural building systems – the right material mix can serve both structural and environmental roles.
Material Breakdown
| Structural Element | Material | Primary Function |
|---|---|---|
| Main structure | In-situ cast concrete | Load bearing, thermal mass |
| Interior core | Oak wood | Warmth, fixed furniture integration |
| Exterior cladding | Concrete-based | Weather enclosure, durability |
| Floating shelving | Oak | Lightweight storage, visual softness |
| Terrace surfaces | Concrete overhang | Outdoor living, solar shading |
Structural designer R J Heiskanen Oy handled the engineering, while Laastu Oü served as the structure contractor. Muurausliike Sami Vanne Oy handled brickwork, and ground works went to Poika ja ämpäri Oy. The project team included a structural engineer, HVAC designer, electrical designer, and garden designer – a full consultant roster that demonstrates the complexity behind what looks like a simple building form.
Concrete and Wood Working Together
The concrete structure provides fire resistance, sound isolation between floors, and the thermal mass that moderates daily temperature swings. The oak core, by contrast, handles the human-scale experience: it contains fixed furniture, shelving, and defines the architectural dictionary of 108 words used by architects describe as “warm” spaces. Architects Anu Puustinen and Ville Hara at Avanto Architects Ltd made the wood core the heart of each house, with smaller, more private rooms tucked inside it.
Interior Layout: Open Living Around a Wood Core
Each Matchbox House centers on an oak wood core that contains the fixed furniture, kitchen integration, and private spaces. Around this core, the living areas open up. The living room features a wood core made of oak alongside in-situ cast concrete surfaces. The formal dining room includes custom lighting and a floor-to-ceiling wall designed for natural ventilation. The kitchen is light-filled, with fixed furniture integrated directly into the wood core. The open layout of kitchen and dining area creates a continuous space that feels larger than the footprint suggests.
Key interior features include:
- Oak wood core at the heart of each house, visible from the entrance
- Floating oak shelving in bedrooms for a lightweight, airy feel
- Modern bathrooms with white and gray finishes
- Floor-to-ceiling windows that bring in natural light from multiple sides
- Custom lighting fixtures in the dining area
- In-situ cast concrete floors in high-traffic zones
The entrance lobby offers a long view straight through the house, ending at what the architects call the “stairway to heaven” – a sculptural staircase that draws the eye upward. This visual axis connects the ground floor to the upper level and makes the house read as a single, unified volume rather than a collection of separate rooms.
Natural Ventilation Strategy
Rather than relying entirely on mechanical systems, the Matchbox Houses use operable windows and the floor-to-ceiling wall in the dining room to create cross-ventilation. The architectural terms and concepts behind this approach are well established: stack effect ventilation draws cool air in at low levels and exhausts warm air through high openings. The overhangs from the upper volume shade the lower-floor windows during summer, reducing cooling loads while still admitting low-angle winter sun.
Outdoor Spaces: Terraces and Site Integration
Every level of the Matchbox Houses connects to an outdoor space. The covered terrace sits beneath the upper floor overhang, sheltered from rain and direct sun. A sunny roof terrace sits above the lower floor roof, accessible from the upper level. This dual-terrace arrangement gives occupants options depending on weather, time of day, and season. In Finland’s climate, where summer days are long and winters are dark, having both sheltered and sun-exposed outdoor areas extends the usable season significantly.
The site plan preserves existing landscape features. Old stone fences, glacial rocks, and mature pines were retained as site anchors. The gently sloping plot, located near the sea, dictated the stepped massing. By how to look at houses like an architect, you can see that the building form emerged directly from site constraints rather than being imposed on them.
Garden Design and Landscape
Garden designer Hanna Hentinen of Piha- ja puistosuunnittelu worked with the existing topography. Native plantings tie the houses to the coastal landscape. The stone fences that predate the construction serve as boundary markers and visual anchors. Pine trees soften the building edges and provide privacy from the street to the north.
Thermal Envelope and Energy Strategies
Although the Matchbox Houses do not carry a formal passive house certification, their design incorporates several principles that reduce energy demand. The concrete structure provides thermal mass that absorbs heat during the day and releases it at night. The compact form factor – two overlapping boxes rather than a sprawling layout – minimizes the surface area exposed to the outside, reducing heat loss through the envelope. This compactness is the same principle behind the goldilocks approach tight houses balance airtightness ventilation that modern energy codes increasingly require.
| Energy Strategy | How It Works in Matchbox Houses | Benefit |
|---|---|---|
| Compact form | Overlapping rectangular volumes | Lower surface-to-volume ratio = less heat loss |
| Thermal mass | In-situ concrete structure | Temperature stabilization, reduced peak loads |
| Natural ventilation | Operable windows, floor-to-ceiling openings | Reduced mechanical cooling needs |
| Solar shading | Upper floor overhangs | Summer cooling, winter passive gain |
| Roof terraces | Upper level accessible roof | Outdoor living without land consumption |
The HVAC design, handled by LVI-Suunnittelu BRL Oy under Ben-Roger Lindberg, supports these passive strategies with efficient mechanical systems sized for the reduced loads. The electric design by Sähkö Solutions Oy / Jukka Ruottinen ensures that lighting, appliances, and systems operate efficiently within the compact volumes.
Construction Timeline and Project Scale
The project moved through a predictable timeline: two years of design (2016-2017) followed by two years of construction (2017-2019). Gross area totals 360 square meters per house, or 720 square meters combined. The client remained private throughout. Project management came from Settle Oy, with Junnu Haapio, Timo Toropainen, and Niko Hänninen coordinating the multiple consultants and contractors.
Design Team Coordination
The project required coordination among nine distinct consulting roles. Interior architects Poiat Office Oy handled the interior finishes, with Timo Mikkonen and Antti Rouhunkoski overseeing the integration of fixed furniture into the oak core. The wood core itself was fabricated and installed by Woodoo Design Oy under Mikko Kittilä, working from detailed shop drawings that aligned with the architectural plans. HVAC contractor PP-Putki Oy and electric contractor Sähkö-Wiik Oy completed the building services in coordination with the structural shell. This level of specialization on a pair of 360-square-meter houses shows how compact projects still demand expert input across multiple disciplines to achieve the level of finish these homes display.
The fixed furniture integrated into the wood core – shelving, cabinetry, and kitchen elements – was designed as part of the architecture rather than added afterward. This integration reduces the need for freestanding furniture and allows the interior volume to read as a continuous space. The oak floating shelving in the bedroom is a clear example: it appears to float against the wall, supported within the wood core structure, eliminating the visual clutter of brackets or legs.
This scale – a matched pair of 360-square-meter houses on a coastal plot – offers a replicable model for compact housing. The architects achieved the feel of a much larger home through careful volumetric manipulation, strategic glazing, and the central wood core that organizes circulation without wasting space on corridors.