opening up a wall for a new window is not a small job; it's a complex construction project that involves structural work, requires specialized trades, and necessitates careful planning to ensure safety and compliance with building regulations. The process involves cutting through the building's structure, potentially installing structural supports, and requires expertise in carpentry, masonry, and finishing work, making it a significant undertaking for even experienced. Opening a wall to install a new window typically costs between £750 on a basic non-load-bearing wall, with costs potentially rising to £2,000 or more for load-bearing walls due to structural requirements, engineer fees, and more complex work like installing an RSJ (rolled steel joist). Factors such as the wall's type, location (especially if on an upper floor requiring scaffolding), the size of the opening, the structural engineer's assessment, and the finishing details all influence the final price... And that does not include cost of window plus fitting