After Polish architecture firm KWK Promes won a competition in 2016 to design a luxury single-family home in suburban Vilnius, Lithuania, a law slashed the allowable building footprint in half. While the client saw this as a reason to move the project to another site, KWK Promes saw the problem from the unique view of architects – where constraints aren’t obstacles but essential drivers of innovation. Thus, the striking triangular form that would be known as the Trim House was born.
The original design was a remarkably luxurious rural home that centered around an atrium to maximize light. This came down to clever stacking. By raising the structure one level, it could double the sky exposure of the central courtyard.
This design placed the public and living spaces downstairs with the bedrooms elevated above the ground floor volume. It was the perfect blend of privacy without losing the connection to the garden. When the new law came in 2017, it threw a curveball at the project that could have cost the architecture firm years of work.
Jakub Certowicz
At the time, Lithuania had a newly elected government that went on to reduce the permissible building coverage by 50%. The regulations also forced the driveway, which allowed for site access, to cut through what was meant to be garden space. To convince the client to stay, KWK cut 40% of the floor area, and to the client’s surprise, this ended up improving the house. It meant more garden space, leading to better lighting conditions for enjoying Lithuania’s northern latitude and tree-covered setting. So the client stayed.
The Trim House spans 299 sq m (3,218 sq ft) and has an unusual triangular footprint. The geometry is quite dramatic too, especially where the building narrows to a sharp point (known in the world of architects as a flat-iron condition). Concrete and glass meet at sharp angles, while a curved courtyard wall softens the harshness.
Jakub Certowicz
As for the inside, a local design and architecture company kept the finishes to a minimum. A white spiral staircase serves as the focal point. Most of the space is adorned with neutral colors, but the kitchen island – with its patterned marble surface – is a standout.
A lush pine forest surrounds the structure. The bedrooms on the upper level have a terrace overlooking these trees while being high enough to provide privacy from the street. Below, living areas open directly to the courtyard, which acts as an outdoor room that brings daylight deep into the house.
Jakub Certowicz
The Trim House was completed in 2025 with no compromises made due to regulatory constraints. KWK Promes has demonstrated this principle before with projects like Open House and Quadrant House, but Trim House’s backstory is particularly compelling: when regulations force your hand, redesign and present the new plan to the client with conviction.
Source: KWK Promes