Can You Build Custom Houses in The Sims 2 Pets (PSP)? No

No. The Sims 2: Pets (PSP) **does not have Build/Buy Mode** or free-form house construction. It is a **linear, story-driven "console-style" port** distinct from the PC/PS2 versions.

Why It's Missing

• Hardware Limits: PSP (333 MHz MIPS, 32/64 MB RAM) cannot stream the texture/mesh data for dynamic lot editing + Sim AI simultaneously.
• Design Choice: Focus on **pet care, mini-games, and narrative goals** (vet career, pet contests) rather than sandbox simulation.
• Different Engine: Built on The Sims 2 (Console) engine (shared with PS2/GameCube/Wii), not PC engine.

What You *Can* Do (Customization)

• Choose Pre-Built Lots: Select from ~10 neighborhoods/lots at move-in.
• Decorate Interiors: Buy/Place furniture, wallpaper, flooring, pet items in **Buy Mode** (accessed via phone/menu inside house). Rooms fixed; walls cannot be moved.
• Create-A-Pet: Full breed/color/trait/voice customization (best feature).
• Train Pets: Tricks, behaviors, contests (Agility, Obedience, Show).
• Socialize: Townies, other pets, romance, WooHoo (off-screen).

Versions Comparison

If you want building: Play The Sims 2 on **PC (Ultimate Collection / Super Collection)**, **PS2**, **Wii**, or **GameCube**. PSP version is a pet-centric adventure, not a house builder.