Making an existing window bigger always requires some construction, but the extent varies by project. Vertical expansions involve less structural work because they often don't affect load-bearing elements. Even so, any enlargement requires removing siding or drywall, cutting framing members, and installing appropriate support. Non-load-bearing walls allow for simpler modifications, while load-bearing walls require proper headers and structural support. A consultation with a structural engineer is advisable before beginning any window enlargement project.
Building permits are required for window enlargement projects in most municipalities. Since enlarging windows involves structural modifications to your home's exterior walls, local building departments need to review and approve the plans. Permit costs range from $100 to $300, though projects requiring significant structural changes may incur permit fees of $500 or more. Additionally, homes in historic districts or those governed by HOAs may need special approvals. Always check local requirements before beginning work.
An average window enlargement project takes between five hours and three days to complete. Simple projects with minimal structural changes might be finished in five to ten hours, while more complex enlargements requiring significant structural modifications could take up to three days. Factors affecting the timeline include the window's location, wall construction, weather conditions, and the need for specialized materials. The process involves demolition, framing, window installation, and interior/exterior finishing work.