1. Check Zoning and Permits in Montgomery County
Before starting any construction, confirm if your property meets local zoning regulations and obtain permits from Montgomery County. Even small additions like bathrooms require approvals to ensure code compliance.

2. Plumbing Access and Layout
The cost and complexity of your new bathroom depends heavily on proximity to existing plumbing lines. Bathrooms built near existing ones or above basements are typically more cost-effective.

3. Water Pressure and Supply Line Upgrade
Older homes in Bethesda may need upgraded water supply lines to support an additional bathroom, especially if the current system is undersized.

4. Septic vs. Sewer Connection
If your property uses a septic system, you’ll need approval to increase usage. For sewer connections, coordinate with WSSC to ensure proper drainage and capacity.

5. Structural Considerations
Adding a bathroom on the second floor or over a crawl space may require structural reinforcements. Always consult a licensed contractor or structural engineer.

6. Space Planning and Functionality
Make sure the new bathroom adds real functionality. A cramped layout can hurt resale value. A well-designed bathroom should be at least 5×8 ft to comfortably fit a toilet, sink, and shower or tub.

7. Moisture Control and Ventilation
Bethesda’s seasonal humidity makes ventilation a must. Install a proper exhaust fan (connected to the exterior) to prevent mold and protect finishes.

8. Material and Finish Selection
Choose durable, water-resistant materials. Bethesda homeowners often prefer timeless finishes like porcelain tile, quartz counters, and high-quality plumbing fixtures for long-term value.

9. Electrical Code Compliance
A bathroom needs GFCI outlets, proper lighting, and a dedicated 20-amp circuit. Always hire a licensed electrician to meet Maryland electrical codes.

10. Budget and Timeline Realism
Expect costs to range from $20,000–$40,000+ depending on scope, location, and quality. Plan for 4–8 weeks from demolition to finish. Hidden issues (like old pipes or rot) may extend the timeline.