Underground parking structures offer long-term benefits, even though they can be more expensive to build and maintain. Here are some key points: 

1. Maximizing Land Value: By constructing parking underground, developers can reserve valuable surface space for mixed-use, commercial, retail, or residential properties. This approach allows cities and developers to take full advantage of available street frontage for retail and commercial uses. 

2. Economic Impact: Consider a typical three-level above-grade parking structure accommodating 450 cars. It requires an approximate footprint of 50,000 square feet. If this space were used for above-grade commercial purposes, it could generate jobs, retail activity, and significant tax revenue. 

3. Costs and Benefits: The average cost per parking space in an underground lot ranges from $25,000 to $50,000, depending on site-specific conditions. Structural support for below-ground garages significantly impacts costs, with up to 70% tied to the structural system. 

4. Site and Design Considerations: Underground parking is often utilized in densely developed urban areas. Temporary and permanent earth retention stabilize the site perimeter during excavation. Understanding design and construction issues is crucial for successful projects. 

5. Entitlement Challenges: Lurking issues include municipal parking requirements, entitlements for subterranean parking, and ADA compliance. Remember that while underground parking may be costlier upfront, its long-term benefits can justify the investment. 

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