Larsen Truss vs Exterior Insulation: Which Is Better? A homeowner planning a cold-climate small house often faces one core decision: reduce thermal bridging by adding a continuous layer of insulation outside the structural frame, or increase cavity depth with a Larsen truss and dense-packed fibrous fill. This comparison—larsen truss vs exterior insulation—walks through how each approach performs for thermal comfort, moisture management, cost, and DIY fit so an owner-builder can choose with confidence. The article explains assembly details, failure modes, and real-world scenarios where one approach usually makes more sense than the other. TL;DR: - Larsen truss gives 2–8 inches of extra cavity for dense-packed cellulose or mineral wool, reducing thermal bridging at studs by separating structure and insulation; best for retrofit depth increases and low-cost fibrous fills. - Continuous exterior insulation (rigid foam, mineral wool boards, nailbase) delivers the cleanest thermal-bridging re...