Row houses and attached dwellings in dense urban areas often suffer from monotonous facades and repetitive interior layouts. The uniformity that makes them efficient to build also makes them visually bland and functionally rigid. The Stacking Box project in Ho Chi Minh City tackled this problem directly by merging two adjacent row houses into a single residence, then reshaping the exterior into a series of stacked cubic volumes. The result demonstrates how stacking box principles can transform cookie-cutter urban housing into something distinctive and livable without requiring a larger footprint.
The Problem of Uniformity in Row House Construction
Row houses built in new urban zones across Southeast Asia share a common problem: planning advantages on paper, but architectural monotony in practice. Identical facades, identical floor plans, identical material palettes – the repetition makes individual units hard to distinguish and entire neighborhoods feel generic. The original condition of the Stacking Box site consisted of two adjacent houses, one sandwiched in the middle of the row and the other on a corner. They were identical in form, separated by a party wall, and suffered from the same lack of diversity that plagues many vertical stacking developments.
Why Uniformity Hurts Livability and Property Value
When every unit looks the same, occupants report lower neighborhood satisfaction and properties tend to appreciate more slowly than those in architecturally diverse areas. The problem is not just aesthetic. Identical floor plans rarely suit the varied needs of different households – a retired couple, a young family, and a work-from-home professional all need different spatial arrangements. Over time, poorly suited layouts lead to vacancy and deterioration. The Vietnamese project site was heading in that direction before the owners decided to merge their two units into a single customized home.
Creating Box-Like Volumes Through Balcony Design
The design team transformed the building’s appearance by rethinking the balcony system. Rather than treating balconies as simple projecting slabs, they wrapped each balcony with twisted wrought-iron barriers and placed a green buffer zone behind the railing. This treatment made each balcony read as a distinct cubic volume attached to the main facade, creating the effect of separate boxes stacking on top of and beside one another. The visual effect is similar to how a stacking tool box system organizes individual containers – each module is distinct yet part of a coordinated whole.
Proportions and Dimensions of Balcony Boxes
Each balcony box in the project measured approximately 1.8 meters wide by 1.2 meters deep, creating a projection that reads as a solid volume from the street. The depth-to-width ratio of 1:1.5 gave each box enough visual mass to register as a cube rather than a thin ledge. Wrought iron barriers curved gently outward, increasing the apparent depth of each box without extending the physical slab. Climbing plants in integrated planters added texture and softened the transition between the rigid box geometry and the open air.
Green Buffer Zones for Thermal Control
The planting behind each railing served a functional purpose beyond decoration. The green buffer absorbed solar radiation before it reached the wall surface behind the balcony, reducing heat gain to the interior rooms by an estimated 15 to 25 percent on the western facade. The plants also filtered dust and provided visual privacy from neighboring buildings, making the boxes both ornamental and thermally beneficial.
| Balcony Treatment | Visual Effect | Structural Approach |
|---|---|---|
| Plain concrete slab | Flat, linear | Cantilevered slab only |
| Wrought-iron barriers | Curved, sculptural | Slab plus railing frame |
| Wrought-iron plus planters | Cubic volume, layered | Slab, frame, green buffer |
| Full enclosure with glazing | Solid box, interior space | Reinforced frame plus glass |
Merging Adjacent Structures for Larger Floor Plates
The most dramatic move in the project was removing the wall that separated the two row houses. The merged building followed the natural horizontal topography of the site rather than the artificial vertical division that had defined the original construction. This created a single floor plate of 250 square meters – substantially larger than either individual unit – and allowed the design to flow freely across the full width of the property. The approach is a practical example of urban residential architecture on compact sites and avoids the cramped feeling that many narrow row houses create.
Structural Implications of Removing Party Walls
Removing a load-bearing party wall requires transferring the loads it previously carried to new beams and columns. In the Stacking Box project, the existing party wall was not fully load-bearing – each house had its own structural frame – so the removal was more straightforward than a full structural retrofit. The staircase location was reconsidered and relocated to improve circulation across the merged floor plate. The corner house was remodeled for communal use while the interior house retained more private functions. This spatial zoning gave the young couple owners a clear separation between public entertaining areas and private living quarters.
Load Paths After Wall Removal
When a party wall comes down, engineers must verify that the remaining columns, beams, and slabs can carry the redistributed loads. In typical row house construction, floors span from the external walls to the party wall, so removing that central support creates a longer span. Steel or laminated veneer lumber beams installed within the ceiling void can bridge the gap without changing floor-to-ceiling heights. In the Ho Chi Minh City project, a steel transfer beam was installed at the second-floor level to pick up the loads from the removed wall section.
Foundation Considerations for Box-Stacking Buildings
When a building expands horizontally by merging adjacent units and vertically through stacked volumes, foundation loads change. The original footings were designed for two separate lightweight structures; the merged building with its added box volumes and potential roof terrace imposes different load distributions. Engineers must check whether existing foundations can handle the new configuration or require reinforcement. The concept of floating foundations can apply when soil conditions are weak and spread footings need to distribute loads over a wider area.
Assessing Existing Footings Before Modification
Before any structural modifications begin, a condition survey of the existing foundations is essential. Test pits at the base of existing columns reveal the depth, width, and material condition of the footings. If the footings are undersized for the merged structure, options include underpinning with concrete, adding micropiles, or installing a reinforced concrete ground beam that connects multiple footings to spread the load more evenly. In this project, the corner property’s footings required minor enlargement to support the added cantilevered box volumes on the western facade.
Curved Façade Elements and Structural Glass
On the western facade of the building, the design team faced a common urban problem: a wall exposed to intense afternoon sun. Rather than blocking the light entirely with an opaque screen, they installed a curved wall made of glass to enclose the staircase. The curvature catches sunlight at different angles throughout the day, creating a changing play of light and shadow on the stair treads. The glass transforms what would otherwise be a utilitarian circulation space into a dynamic experience.
Glass Selection for Curved Facades
Curved glass walls require tempered or laminated units that can handle the bending stresses of installation and the thermal stresses of direct sun exposure. Laminated glass with a low-emissivity coating reduces heat gain while maintaining transparency. The frame material must match the curvature – aluminum extrusions can be curved to match the glass profile, while steel frames require custom fabrication. The Vietnamese project used a steel frame with laminated glass panels, chosen for its ability to handle the thermal load of the western exposure.
Structural Framing for Box-Volume Buildings
The structural system for a box-volume building must handle the loads from projecting balconies, cantilevered box elements, and the spanning requirements of merged floor plates. Reinforced concrete frames with infill masonry walls remain the most practical choice for this type of project in dense urban environments. The concrete frame handles the eccentric loads from offset box volumes and provides the stiffness needed to resist wind loads on the exposed corner facade. For larger spans, steel transfer beams or box girder sections can bridge the gap where internal walls have been removed.
Load Paths for Cantilevered Box Elements
Each projecting balcony-box creates a cantilever that transfers moment forces back to the main structural grid. Reinforcement detailing at the slab-column connection must account for the reversal of bending moments – at the face of the support, the top fibers are in tension, requiring additional top reinforcement. For boxes that project more than 1.5 meters from the facade, a deeper edge beam or post-tensioned slab section is typically required to control deflection and vibration. Wind uplift forces on the underside of projecting boxes must also be considered, particularly on exposed corner sites where wind pressures are higher than in sheltered mid-block positions.
Stacking box architecture offers a practical method for upgrading mediocre row houses into distinctive urban homes. By merging adjacent units, reimagining balconies as cubic volumes, and using structural glass to enclose circulation, the approach creates generous interiors on tight footprints. Foundation assessment, careful load path detailing, and appropriate gutter box integration for rainwater management complete the package, making the building perform as well as it looks.