Sustainable strategies for vacant houses ( akiya ) in shrinking Japan: balancing demolition and heritage preservation

Purpose Japan’s vacant houses (akiya) simultaneously threaten public safety and embody cultural heritage, creating a policy dilemma between demolition and preservation. This study investigates how four municipalities balance demolition with adaptive reuse and which policy mixes prove most effective across urban–rural contexts. Design/methodology/approach A systematic content analysis of 74 primary documents (Kyoto 22, Setagaya 17, Nagano 16, Tottori 19) was conducted in MS Excel. A structured codebook with five dimensions—intervention type, legal basis, fiscal magnitude, policy objective and heritage linkage—was applied to all documents. A 10% sub-sample was re-coded after a four-week interval, yielding intra-coder reliability = 0.80. Dimension scores were normalised and combined to plot a two-axis demolish–preserve strategy matrix. Findings Kyoto deploys a reuse-dominant portfolio (68%) with strong heritage clauses, placing it in a “preservation-intensive” quadrant of the strategy matrix. Setagaya allocates almost half of its akiya spending to demolition, exemplifying a “hazard-mitigation” approach. Rural Nagano and Tottori emphasise incentive-led renovation (>70% reuse instruments) but diverge on regulatory force, both falling into a reuse-oriented quadrant. Practical implications The demolish–preserve matrix enables local governments to benchmark and adjust their instrument mix. Heritage tax relief and demolition-notice ordinances suit Kyoto-type cities, while targeted demolition subsidies and estate-planning clinics better serve Setagaya-like suburbs. Originality/value This offers a cross-level, instrument-scale comparison of Japanese akiya policy. By bridging demolition and preservation perspectives, it offers a framework that planners in other shrinking regions can use as a rapid diagnostic to align safety, cultural continuity and fiscal capacity.