Open-plan loft design presents unique opportunities for creating fluid, multi-functional living spaces. The approach draws heavily on the architectural vocabulary of raw industrial structures – exposed concrete, timber columns, and full-height glazing – where the building shell itself becomes a primary design feature. In projects like the 100 m² His Loft in Amsterdam-Noord, architects work with an existing “casco” or shell-and-core delivery, adapting the interior to suit residential and professional needs while preserving the spatial character of the original structure.
The Casco Building as a Design Starting Point
A casco building delivers a completed structural shell – floors, columns, roof, and façade – with all internal fit-out left to the occupant. This delivery method originated in the Netherlands and has become popular in loft developments across Europe. The architectural dictionary term “casco” refers specifically to this shell-and-core approach, where the building’s concrete slabs, columns, and glazed envelope are finished, but interior partitions, services, and finishes are not.
The His Loft project sits inside the Top-Up building, constructed according to this open building idea. The structure features concrete slabs and a concrete ceiling held together by massive timber columns. A full-height glazed facade runs along one side, flooding the space with natural light. These elements together create what architects call a “strong spatial concept” – the raw building fabric sets the tone, and the interior design responds to it rather than competing with it.
Structural Exoskeletons versus Interior Infill
In traditional construction, the structure and interior finishes are designed and built together. In casco projects, they are separated by both design phase and contractor. The structural elements become permanent sculptural features, while everything inside can be reconfigured over time. This separation offers several practical benefits:
- Lower upfront cost – the developer delivers only the shell, reducing initial capital requirements
- Design flexibility – each occupant customizes the interior to their own needs without demolishing existing work
- Simplified maintenance – services running in raised floors or exposed ceilings remain accessible without breaking into finished walls
- Longer building lifespan – the structure can outlast multiple interior fit-outs, reducing demolition waste
How the Open Building Concept Serves Residential Lofts
The open building concept treats a building’s support structure as a long-term investment and the interior infill as a short-to-medium-term layer. This aligns naturally with loft living, where occupants often want large, unobstructed spaces rather than subdivided rooms. The concrete slabs and timber columns in the Top-Up building are not hidden behind drywall – they define the aesthetic. Architects then add only what is necessary for living: flooring, cabinetry, services, and minimal interior partitions.
Working with a Restricted Material Palette
The design team at Kevin Veenhuizen Architects committed to no more than two added materials for the entire loft interior. A continuous smoked oak floor runs across all zones, unifying the disparate functions under a single surface treatment. Three sculptural boxes clad in ash timber house the kitchen, bathroom, storage, and workspace. The Kevin Roche scholarship program similarly emphasizes that young architects learn to achieve maximum effect with minimal means – a design discipline that applies directly to material selection in residential interiors.
Limiting materials forces deliberate decisions. Each surface, joint, and transition matters because there are no secondary materials to distract the eye. The smoked oak flooring provides warmth and visual continuity. The ash timber boxes introduce a lighter, grainier texture that contrasts subtly with the oak while remaining within the same tonal family. Together, they create a calibrated interior where the concrete shell remains the dominant visual mass.Comparing Material Strategies in Open-Plan Interiors
| Approach | Materials Used | Visual Effect | Suitability |
|---|---|---|---|
| Minimal palette | 2–3 materials | Calm, unified, spacious | Small lofts, studios |
| Moderate palette | 4–6 materials | Warm, layered, textured | Family homes, larger lofts |
| Eclectic palette | 7+ materials | Dynamic, bold, expressive | Commercial, showpiece homes |
The His Loft sits firmly in the minimal palette category. Every added surface performs at least two roles: the smoked oak flooring is both a walking surface and a visual unifying element, while the ash boxes are simultaneously storage, room dividers, and architectural features.
Selecting Flooring as the Primary Unifying Surface
In open-plan lofts, the flooring material carries an outsized visual responsibility because it is the one surface visible across every zone. A continuous material – whether smoked oak, wide-plank pine, polished concrete, or large-format tile – eliminates visual breaks and makes the space feel larger. The His Loft uses a single smoked oak flooring throughout, including under and around the ash timber boxes. This treatment makes the boxes read as furniture placed on the floor rather than as permanent construction, reinforcing the conceptual separation between shell and infill.
Zoning Interior Space with Architectural Boxes
Rather than building walls that reach the ceiling, the His Loft organizes its functions around three freestanding boxes clad in ash timber. These boxes function as large pieces of furniture, each housing a specific set of activities. Spaces flow between and around them, creating zones without doors or corridors. Understanding who owns an architect’s plans and design rights becomes relevant when adapting such bespoke interior solutions for repeat use in multiple units – the intellectual property in a custom box system may require licensing agreements for reproduction.
Box One: The Kitchen-Dining Island Hybrid
The first box sits on a tiled recess in the floor and combines an angular kitchen island with a circular dining table. This single piece of tailor-made furniture links cooking, eating, and social functions within the daytime activity zone. The tile inset anchors the box visually and protects the oak flooring from water and food splashes in the kitchen area. This hybrid approach reduces the number of freestanding furniture pieces and creates a deliberate transition from the cooking zone to the living area.
Design Parameters for Multi-Function Furniture
- Height transitions – the island surface (standard counter height, 900 mm) and dining surface (standard table height, 750 mm) must be resolved in a single form
- Material continuity – the box cladding should transition cleanly between functional zones without visible seams
- Service integration – plumbing and electrical for the kitchen must route through or under the box without compromising the clean exterior
- Accessibility – the combined piece should accommodate seated dining on one side and standing food preparation on the other
Box Two: The Two-Faced Room Divider
The second box presents two distinct faces. On the living room side, open shelves form a small library and house appliances. On the reverse side, the box contains a bathroom and WC, with an intimate sleeping zone tucked behind it. The key design choice is that the box does not reach the ceiling and does not form a full-height wall. Instead, it creates a visual and acoustic screen while preserving the volumetric continuity of the overall space. The sleeping zone feels private but remains visually connected to the rest of the loft.
Integrating Professional Workspaces into Residential Interiors
The His Loft dedicates twenty-five percent of its physical envelope to professional activities. This ratio reflects a growing trend in residential design – the lines between home and work have blurred, and contemporary lofts must accommodate both without sacrificing either. The third ash timber box defines the workspace while also housing a closet, storage room, visitor toilet, pantry, and open shelves. This box functions as a fully autonomous guest room with a shower and kitchenette, separated by a wall that slices through the box volume. Career pathways for senior project architects increasingly emphasize skills in flexible residential-commercial hybrid design, as more clients request home offices that meet professional standards.
Service Distribution for Flexible Zones
All services – electricity, heating, running water, and ventilation – are delivered at the doorstep of two primary areas rather than distributed throughout the entire loft. A raised floor system carries these services, providing maximum flexibility to reconfigure the interior without breaking into concrete slabs or running exposed conduit. This approach reduces installation time and material waste compared to chasing services into walls that may later be relocated.
| Service System | Traditional Method | Raised Floor Method | Benefit |
|---|---|---|---|
| Electrical | Embedded in walls | Under-floor raceways | Re-routable |
| Plumbing | Chased into partitions | Floor-level distribution | Accessible |
| Ventilation | Ceiling ducts | Under-floor plenum | Flexible outlets |
| Heating | Wall radiators | Under-floor radiant | Even coverage |
Constructing the Box System for Repeatable Installations
The ash timber boxes in the His Loft are built as cabinetry rather than as structural walls. This distinction matters for construction cost, timeline, and future adaptability. Carpenters or cabinet makers construct the boxes off-site, then install them as finished units. The result is a clean, precise interior with minimal on-site finishing work. Aluminum-framed interior wall systems offer an alternative approach for projects where the boxes need higher fire resistance or sound isolation than timber cabinetry can provide, combining the flexibility of furniture-scale construction with the performance of permanent partitions.
Cost and Timeline Comparison for Interior Partition Strategies
- Drywall partitions – lowest material cost, longest on-site time, creates permanent rooms, difficult to modify
- Freestanding furniture boxes – moderate cost, off-site fabrication, fully reconfigurable, requires skilled cabinet makers
- Aluminum-framed demountable walls – higher upfront cost, fast on-site assembly, good acoustic performance, reconfigurable with proprietary components
- Glass partitions – highest cost per linear meter, preserves visual openness, provides acoustic separation, limited privacy without blinds or film
Applying Zoning Strategies in Residential Loft Conversions
The principles demonstrated in the His Loft translate to a wide range of residential projects beyond the Amsterdam original. Any open-plan space – a converted warehouse, a barn renovation, a double-height extension – can benefit from the box-zoning approach. The key steps involve identifying which functions need enclosure (bathroom, storage, workspace), designing those as freestanding volumes, and letting the remaining space flow around them. Professional organizations continue to shape these conversations; AIA New York’s push for architects to reconsider the types of buildings they design reflects a broader re-examination of how architectural skills are deployed across residential, civic, and commercial projects.
The three-box solution in this 100 m² loft achieves a remarkably complete residential program: sleeping, cooking, dining, living, working, bathing, guest accommodation, and storage – all within a space smaller than many one-bedroom apartments. Each function is clearly defined by its relationship to the boxes, yet no function is fully enclosed. The result is a home that feels larger than its floor area because the visual field is never blocked by full-height partitions. For architects and designers working on compact interiors, the lesson is straightforward: subtract walls, add boxes, and let the space do the work.