# Partner Engineering and Science

Phase I assessments on lender timelines.

A national environmental and engineering consultancy whose Phase I Environmental Site Assessments are a fixture of lender closing checklists. Reports follow the current ASTM E1527-21 standard, the firm participated in creating and updating that standard, and its own page says it supports approximately one in five commercial real estate transactions nationwide, from a single site to a portfolio.

- Category: Closing Vendors
- Pricing model: Custom Pricing
- Where it fits: Diligence & Close the Deal
- Website: https://www.partneresi.com

## At a Glance

The default national name for the [Phase I](https://searchspheresource.com/glossary/phase-i-environmental) on a lender's checklist; confirm who orders it before you hire them yourself.

## What It Costs

No published pricing; engagements are scoped and quoted. The firm's Phase I page (read Aug 2026) describes the product and the standard but carries no rate card, which is normal for this vendor class.

## Best For

The Phase I your lender orders on any acquisition that includes real property, especially where a fueled, industrial, or dry-cleaning past use makes currency with the ASTM standard matter. If the deal is a leased-premises [asset purchase](https://searchspheresource.com/glossary/asset-vs-stock-sale), ask the lender whether a cheaper records search satisfies them first.

## Pros and Cons

- Pro: Scale you can verify on their own page: founded 2007 and supporting roughly one in five commercial real estate transactions nationwide
- Pro: Standard-setting depth: the firm participated in ASTM E1527 standard creation and updates, so reports track the current 2021 requirements
- Pro: Delivery model spans a single-site acquisition to a multi-state portfolio without changing vendors
- Con: Built for commercial real estate lender panels, so your lender may order the report directly and hiring your own copy duplicates the spend
- Con: No published pricing or turnaround; everything starts with a scoped quote

## What Searchers Say

Founded 2007; describes itself as one of the most experienced providers of ASTM-compliant Phase I ESAs in commercial real estate, supporting about 1 in 5 transactions nationwide (own site, Aug 2026).

## Compared With

- Which Phase I firm for your deal, the lender-panel fixture or the open-book one? (https://searchspheresource.com/resources/compare/partner-esi-vs-aei-consultants.md)

## Sources

- https://www.partneresi.com/services/environmental-due-diligence/phase-i-environmental-site-assessment/

Also on this site: https://searchspheresource.com/resources/category/closing-vendors.md
Source: https://searchspheresource.com/resources/partner-esi
Last checked: 2026-08-13

Site index for machines: https://searchspheresource.com/llms.txt