Heartwood

A mid-rise timber solution to affordable housing and climate change.

Heartwood is an eight-storey, 6,267 m² residential building delivering 126 housing units on a compact urban site. As the first US project built “as-of-right” under new Type IV-C tall timber codes, it proves mass timber’s viability at a mid-rise project scale.

Responding to Seattle’s twin crises of climate change and housing affordability, it offers middle-income apartments with shared courtyards and active ground floors to foster social interaction and urban vitality.

Completed in 2023 and constructed with 1,020 m³ of locally sourced glulam, CLT, and LVL, Heartwood cut its structural carbon by 38% compared to concrete and achieves a carbon-negative balance when stored biogenic carbon is included. Designed for adaptability and disassembly, 80% of its timber can be reused—offering a replicable, climate-positive model.

 

 

 

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