How Do I Run Comps for a Property That Doesn't Exist Yet?

December 22, 2025 | Kristi Kandel

ASK:

How can I estimate rents or sales prices when my project hasn’t been built?

ANSWER:

When you’re developing something new, there won’t be a perfect comparable sale, and that’s okay. Developers use a mix of market data and logic to project what a finished project will be worth.

Here’s how:

1. Start with Location: Find the closest properties that match your concept in size and quality.
2. Adjust for Quality and Timing: If your project is new, it may rent or sell for 5–15% more than older ones nearby. This is completely market dependent. 
3. Check Active Listings: What are new or renovated properties asking in your area? That tells you the current ceiling.
4. Talk to Local Brokers: They’ll give you honest local insights on what’s leasing or selling beyond the listed prices. Brokers can be incredibly insightful in the early stages. 

Then, apply your conservative number to your pro forma. If new builds are renting for $2.50 per square foot, run your model at a more conservative rate (example: $2.25) to add buffer. However, test all assumptions with local market experts based on what they are seeing with other properties. 

This is how developers balance optimism with caution and why development is an art just as much as it is a science.

KEY TAKEAWAYS:

• Use nearby comps and adjust for quality and timing.
• Always project conservatively; don’t assume record-high prices.
• Brokers know the “real” market better than online listings.

PEOPLE ALSO ASK:

How recent should comps be?

• Within 6–12 months so they reflect current demand and interest rates.

What if there are no perfect comps?

• Use the closest type and explain your assumptions clearly in your model.

Should I trust online sites for data?

• Use them for ballpark numbers, but also verify through brokers, appraisers, 

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