Energy-efficiency has received much attention from policy makers and the issue of reducing energy consumption in buildings has faced a true challenge in balancing incitements, restrictions and cost-effectiveness for required changes. The literature shows that technological change and technology diffusion is an important factor in overcoming cost barriers. On the other hand, before adaptation process begins the new technology must show possibility for profit and return on costs. This paper aims at discussing technological change in building construction in context of diffusion and adaptation of very low-energy technological solutions. We are tracing technological development in three aspects: wall construction, windows energy-efficiency improvement and mechanical ventilation, solutions used preliminary in construction of passive houses. We examine how those technological changes influenced cost-effectiveness and profitability of low-energy building projects. The investigation is approached by analysis of market and policy incentives and the role those factors had on diffusion of new energy-efficient technologies.