In order to build on a small footprint, most Accessory Dwelling Units (ADUs) sacrifice circulation space. This project leverages a shared corridor as the central spine of the ADU to create a new typology for housing that is both programmatically flexible and adaptable to a variety of sites. The corridor is marked by a pair of lightwells which extend the space vertically and horizontally, bringing light and passive ventilation through the house. They provide a space for rest and separation of private rooms from the central space of the house. These lightwells give the building a unique presence from the street, while maintaining privacy for the resident, subverting the paradigm of the ADU as a secondary dwelling hidden behind the primary house.
Instead of parametrically generating a single “optimized” plan for a given site, the above matrix offers a set of options that can be chosen from based on an iterative design process. Plans are designed to fit on a variety of typical lot types in Houston to maximize efficiency. Each ADU plan starts with the corridor, containing a pair of lightwells. Rooms branch off the corridor and can stack, producing a series of alternating interior and exterior spaces.
The right hand lightwell serves as the entry threshold, with doors leading to the front and back porches. The end conditions of the plan are the private bedrooms, which have sliding doors opening onto the shared corridor. They are separated by the lightwells from the common space of the kitchen and living room. In this plan, a larger L-shaped kitchen accommodates more dining space. The addition of a second bedroom introduces a lightwell garden looking onto the kitchen. The fenestration is primarily organized along the horizontal axis, maximizing privacy.
Sliding doors allow the bedrooms to spill out onto the corridor, extending the spaces into the common area of the house. The syncopation of rooms down the corridor expands the space horizontally, and the lightwells extend it vertically, making it a light and open space that is meant to be occupied. Individual rooms feel visually and spatially connected, allowing for a variety of activities within a relatively small footprint. The hallway doubles as both a circulation and programmed space, momentarily redefining what constitutes the corridor.
Corrugated metal siding for the wall and the roof assembly is used for both its reduced cost and prevalence in Houston, where it has been appropriated as both a high and low-end material.
The choice of a singular cladding material also enforces the ambiguity between roof and walls. The height of the light wells further emphasizes this ambiguity. At 18', this double-height volume can be read as both a one or two-storey structure.
The second bedroom at the end of the hallway can double as an office and offers views through the lightwell garden and into the kitchen beyond. The corridor features a built-in storage unit with open shelving to create a more defined space for the living room, which sits behind it.
When placed together in a neighborhood, the ADUs form a visual connectivity across sites. The home’s distinctive materiality and form produce a new type of urban collectivity organized around the rear of the site, emphasizing both the verticality of the lightwell.