The timeline for a home addition typically spans 8 to 12 months and involves several key phases. The design phase, lasting 1-2 months, involves planning the layout and features of the addition. The permitting phase, taking about 3-4 months, includes obtaining necessary approvals from local authorities. Finally, the construction phase, which can take 4-6 months, involves the actual building process. The exact duration may vary depending on the complexity of the project and specific site conditions.