Apers vs. CoStar

Overview

CoStar is the dominant provider of commercial real estate data, analytics, and market intelligence. It owns CoStar, LoopNet, Apartments.com, and Ten-X. If you work in institutional CRE, you almost certainly have a CoStar subscription. It's the source for comparable sales, market rents, vacancy rates, and property-level data.

Apers is a deal underwriting and modeling system. It reads documents, builds financial models, and generates IC-ready Excel workbooks. It doesn't provide market data — it uses data (from whatever sources your team relies on, including CoStar) to build models.

These tools operate at different layers of the investment stack. CoStar provides the data. Apers builds the model. Comparing them is like comparing Bloomberg Terminal to Excel — different tools, often used by the same person, for different parts of the same workflow. For more on how Apers fits in the CRE stack, see the full comparison overview.

Different Layers of the Stack

Table 1 — CoStar provides market intelligence; Apers builds financial models. They occupy different layers of the institutional investment workflow.

Pricing Context

CoStar and Apers occupy different budget line items entirely. CoStar subscriptions typically run $300-500 per user per month for the analytics suite, with enterprise contracts reaching significantly higher depending on the modules included (CoStar, LoopNet premium, STR, Apartments.com analytics). It's a market data subscription — the cost of access to comparable sales, market rents, and property intelligence.

Apers starts at $19/month for the Basic tier (100 Smart Request Credits per month), with Pro at $99-129/month (1,000 credits) and Enterprise pricing for larger teams. It's a modeling tool subscription — the cost of generating financial models, extracting deal documents, and running sensitivity analysis.

These aren't competing budget items. CoStar is a data cost. Apers is a productivity cost. The question isn't "CoStar or Apers" — it's whether your team needs market data (yes, almost certainly) and whether your team needs faster modeling (depends on deal volume). Most institutional shops will carry both subscriptions, and the combined cost is still less than a junior analyst's monthly salary.

When CoStar Wins

• Market data and comps. There is no substitute for CoStar's comparable sales database, market rent data, and property-level intelligence. If you need to know what multifamily assets traded for in Phoenix last quarter, you go to CoStar.
• Deal sourcing. Property search, listing alerts, and broker contact databases. CoStar (and LoopNet) are where many institutional teams find deals in the first place.
• Market analysis. Submarket trends, supply pipeline, absorption data, rent forecasts. CoStar's analytics inform the assumptions that go into your financial model.
• Portfolio benchmarking. Comparing your properties' performance against market averages. CoStar's dataset makes this possible at scale.

When Apers Wins

• Turning data into models. CoStar tells you the market cap rate is 5.25%. Apers' knowledge engine builds the acquisition model that uses 5.25% as an input, calculates the purchase price, sizes the debt, models the waterfall, and produces a sensitivity table showing returns at 5.0%, 5.25%, and 5.5%.
• Document-to-model pipeline. You found the deal on LoopNet. The broker sent an OM. Now you need to extract the rent roll, reconcile it against the T-12, and build a model. CoStar doesn't participate in this workflow. Apers does.
• Complex deal structures. Waterfall distributions, LIHTC basis calculations, multi-tranche debt sizing, development pro formas. These are modeling problems, not data problems.
• IC preparation. Going from a populated model to a recommendation with auditable assumptions and sensitivity analysis. CoStar informs the assumptions; Apers builds the model that presents them.

What CoStar Doesn't Do

CoStar is indispensable market infrastructure. But teams regularly overestimate what it covers in the underwriting workflow. Here's what CoStar does not do:

• Generate financial models. CoStar provides analytics dashboards and market data. It does not produce Excel workbooks with cash flow projections, return calculations, or auditable formulas. The model still needs to be built.
• Extract data from deal documents. When a broker sends an OM, rent roll, and T-12, those documents need to be read, reconciled, and mapped into a financial model. CoStar doesn't touch broker documents — its data lives in its own database.
• Size debt. CoStar can tell you what debt terms look like in the market. It cannot calculate maximum loan proceeds based on DSCR, LTV, and debt yield constraints across senior, mezz, and preferred equity tranches.
• Model waterfall distributions. Multi-tier promote structures, catch-up provisions, GP co-invest, clawback — these are financial modeling problems. CoStar doesn't model partnership economics.
• Run sensitivity analysis. CoStar provides point estimates. It doesn't generate sensitivity tables showing how returns change across a matrix of assumptions — exit cap rate vs. rent growth, leverage vs. hold period.

The gap between CoStar's output and an IC-ready recommendation is the entire underwriting workflow. CoStar informs the assumptions that go into your model. It does not build the model that uses them. Teams that assume CoStar's analytics are sufficient for underwriting discover this gap the first time they try to present a deal to their investment committee without a populated financial model behind it.

Using Both

Almost every Apers user also uses CoStar. The workflow is natural:

1. Source the deal — find it on CoStar/LoopNet, or receive the OM from a broker.
2. Pull comps from CoStar — comparable sales, market rents, cap rate benchmarks for the submarket.
3. Upload documents to Apers — the OM, rent roll, T-12, and any other deal documents.
4. Apers generates the model — using extracted deal data and your market assumptions (informed by CoStar) to produce a complete Excel workbook.
5. Review and adjust — refine assumptions based on CoStar's market data, run sensitivities, prepare for IC.

CoStar and Apers aren't competing for the same budget or the same workflow step. CoStar is market infrastructure — essential and irreplaceable. Apers is analytical infrastructure — the tool that turns CoStar's data and broker documents into investment decisions.