Brian O'Brian's Hemlock House Turns Ontario Farmland Into Architecture

A 72-acre property in Markdale, Ontario, now holds a 3,250-square-foot (302-square-metre) weekend house that Toronto-based architect Brian O'Brian dressed in corrugated metal and topped with a planted green roof. He calls it the Hemlock House.

The commission didn't start that way. The client originally wanted to renovate a 1930s farmhouse on the land, but the brief grew until renovation stopped making sense.

"What started as a modest renovation evolved into a full replacement of the small, 1930s farmhouse," O'Brian said.

The client found him after seeing another of his projects nearby: a 19th-century schoolhouse with stone walls that O'Brian converted into a cottage.

What does the house actually look like?

The building sits on a flat site ringed by woods and farmland. It's composed of two parts:

• a long, linear bar spanning two levels
• an adjoining box holding the shared living spaces

The bar volume carries a sloped, metal-clad roof. The attached box gets an angular green roof planted with vegetation. A carport sits under a canopy of wood and metal.

A long entry driveway sets the tone before anyone reaches the front door. It, in O'Brian's words, "traces the lineage of the site", passing the old farmhouse and a century-old barn on the way in. The new house "extends the language of agricultural buildings into a contemporary domestic form", the architect said.

How does the envelope work?

The two long elevations behave very differently, which is the whole trick of the design.

The north side is a slanted wall of corrugated metal — austere, shed-like, deliberately so. Three windows are cut into it, each covered by an external perforated steel panel that slides up and down. A boxy protrusion with wood cladding interrupts the rhythm.

"This is meant to feel like an agrarian building at first view, but one that begins softening and opening on approach," said O'Brian.

The southern elevation drops the disguise. It overlooks patios and a swimming pool and opens up with hemlock siding and ample glazing. Roof overhangs of varying depths shield the rooms from sun and snow — a practical detail in southern Ontario, where both arrive on schedule.

How is the interior organised?

Inside, the plan splits cleanly between public and private. The two-level linear volume holds a principal suite, a secondary suite, and two bedrooms sharing one bathroom. The adjoining box contains the kitchen, dining area and living room.

The palette stays neutral, mixing earthy and industrial materials without much fuss.

"Concrete and hemlock define every surface, carrying a steady material logic through the house," the architect said.

Two materials, held to consistently, in a house that replaced a farmhouse it was meant to fix. The Hemlock House joins other recent Ontario work, including UUfie's renovated 1970s chalet and Barbora Vokac Taylor's black cabin with wedge-shaped clerestory windows, in a quiet run of rural projects testing how far farm building language can stretch.