Residential insulation retrofit research, 1975 to 2026, in numbers

Counts of the peer-reviewed literature on insulating and retrofitting homes, drawn from the OpenAlex index on 9 November 2026 with seven narrow title-and-abstract queries (journal articles and reviews, 1975 to 2026). 5,091 works match; 3,686 fall in OpenAlex's building and construction subfield and form the core. Core output rose from 142 works in the 1990s to 1,318 in the 2010s and 1,328 in 2020 to 2025 (peak 2025, 332 works). China, United Kingdom and United States lead by author country; Canada ranks 6th with 109 works. Three journals carry 17% of the core. 55% of core works are open access, 76% for 2020 onward. Files: the typeset note (PDF) and its groff source, works.csv with every matched work (abstract and query tags included), per-year, per-country and per-venue counts, the 25 most cited core works, the exact queries with their counts and fetch times, and the two Python scripts that reproduce everything. Funding: the author's time was covered by Patterson Insulation (https://pattersoninsulation.com), a Lethbridge, Alberta contractor whose day-to-day work is the subject of this literature: spray foam and blown-in attic insulation, insulation top-ups and air sealing for houses, shops and farm buildings across southern Alberta. The funder set no terms and saw nothing before deposit.