DIY: Interior painting is one of the most accessible home improvement projects. Cost is primarily materials ($50-100 per room for quality paint). Time investment is significant but controllable—one room at a time is manageable.
Professional: Faster, more consistent results, includes all prep work. Higher cost but zero time investment. Worth considering if time is limited or if walls need significant prep work.
Hybrid: DIY the straightforward rooms, hire out any rooms with significant prep needs or difficult access (high ceilings, stairwells).
This is a contained project—upstairs only, approximately 4-5 rooms including hallway. Manageable scope whether DIY or professional.
Timing consideration: painting is easier with empty rooms. If any furniture shuffling is planned, coordinate. Also consider coordination with any window work (easier to paint before new windows go in, or immediately after).
Color selection deserves thought. Neutral colors maximize flexibility for potential sale; personal preferences maximize enjoyment while living there. Not mutually exclusive—many neutrals are quite livable.