It’s been five years since Ann Arbor, Michigan, amended its zoning regulations to allow for accessory dwelling units, or ADUs. The increasingly popular typology has been hailed as a highly practical way to boost housing affordability, allow for multi-generational residential arrangements and gently increase density in urban neighbourhoods. But there was very little movement in this area – until recently.

In 2021, two principals of T+E+A+M – Ellie Abrons and Adam Fure – completed one of the city’s very first ADUs, in the backyard of an existing single-family home. Clad in structural insulated panels (a combination of metal, fibre-cement board and mesh that together create a tight, high R-value envelope) and internally lined in laminated strand lumber, the 68-square-metre dwelling feels both light and industrial.

It is, in fact, light on the ground: using shallow foundation technology, the WarmFörm system by ByggHouse, the duo was able to build on the ground rather than digging deep. Common in Scandinavia, the technique promises to be highly insulating and frost-protective.

Things are kept cozy inside by radiant heated floors and mini-splits – and by the intriguing use of the aforementioned LSL. Wrapping the upper walls and ceiling, the exposed joists create a warm energy, while staggered ceiling heights created by the convergence of the ADU’s main volume and its bedroom pavilion bring in light from variously positioned windows and skylights. Metal mesh reappears in the home as guardrails for the staircase and the mezzanine.

The project shows that it’s possible to build these types of projects, designed by architects, at non-astronomical costs (with a budget of $3,757/sqm, the dwelling came in at around $255,500) – and to experiment with form, texture and environmental construction techniques along the way.