TY JOUR TI Modern Problems and Prospects of Major Repairs of Multi‑Apartment Buildings with Expiring Service Life KW physical deterioration of housing KW major repairs KW multi-apartment buildings KW housing stock KW repair and restoration works KW regulatory framework KW financial sustainability JO Construction production AU Lapidus, A.A. AU Kuzmina, T.K. AU Mamonova, A.I. AU Gavrilova, A.G. PY 2026 IS PB Publishing Center RIOR