Accessory Dwelling Unit Re-Think / Yeh-Yeh-Yeh Architects
Text description provided by the architects. ADU as we understand from the term “Accessory Dwelling Unit” implies an accessory house that belongs to the main house. Our initial design was driven by rethinking the value of ADU not as a secondary house and discovering any overlooked aspects that might be interesting and effective in design. There are many reasons people are building ADU, but the intended use of this ADU is for a rental unit. Therefore, we constantly envisioned the future potential renters and their lifestyles when we design the building.
The location of ADU has a beneficial effect on design. One of the typical locations of the garage in old houses in Los Angeles is the rear end of the property after a long driveway. The driveway is used as a parking space for the front house and also as a walkway leading to the back house. We want to make this walkway for the renters to feel entering their own place by designing a gravel path and gate with a front garden. Besides the ADU being located further inside the street, the view of the street beyond the new house is much deeper and more enjoyable.
Create a balance between the two houses. Since we know the new house will be used as a rental unit, privacy is one of the important considerations of design. There are no windows looking into the backyard of both houses for privacy but an oversized skylight in the hallway in the new house permits natural light and ambient mood in the space. The setback by the code allows another intimate outdoor space in the back of the house possible to utilize as a vegetable garden or for other purposes. Beyond the privacy for each other, there are two more design elements to consider.
First, many ADU is converted from garage space which is mostly used as a big storage space for the homeowners then they lose storage space immediately. To compensate for the need for storage space, 50sqf of accessible space is allocated to the existing house for storage. Second, the facing walls or elevations of the new house toward the existing house are important views from the backyard in the existing house. They need to be aesthetically pleasing for residents in the existing house.
Building shape and material become an identity. We applied a new building finish technique to make this hidden monolithic object grounded between two houses. Regarding the materials for the exterior, the old-time construction technique from Korea has experimented on the walls of the house. It is called “Jongseok Mijang” and it is a scraping process a few hours later after the cement/gravel mixture applies to the wall. The mock-ups had been implemented before it actually, applied to the walls. The variation of gravel sizes and shapes, the cement color, and the amount of sand affect the result of the finish. It is also affected by the weather. Its strong and brutal finish is visual when a scraped-out pocket gets a shadow effect in a metal-trimmed volume. The finish also becomes energy efficient.
The thermal mass that the walls provide to a building is able to absorb heat during the day and release it at night. This passive transfer smooths out heat transmission through the walls and limits the need for mechanical systems. The smooth white painted MDO panel and aluminum exterior finish contrast with the cement/gravel finish. The courtyard pavers continue the same aesthetic as the walls. The contained geometry always set the boundary for the natural or uncontrollable materials and this contrast is creating more effective materiality. Turfstone pavers are laid in a herringbone pattern and it generates natural edges for the landscape. The gravels contrast with the pattern. Functionally, the Turfstone permeable paver allows rainwater to be gradually filtered back into the soil naturally, resulting in the control and stabilization of soil erosion.
The volume initiated from a minimum length of overhang by the code is created into an angled geometry. It is attractive and functional. The exterior angled line of overhang continues the interior ceiling line to complete the rectangular shape. This creates soffit lights in the living/kitchen open space. The skylight in the hallway brings daylight into the space with minimum wall windows for privacy and acts as a focal design feature. The material palette of the interior is limited to white and light birch plywood to create the small space more expansive and recognizable by light and shadow and to give a canvas for furnishing.