Running your first underwrite: end-to-end walkthrough

Overview

This walks you through your first complete underwrite in Archer — from finding a property to having a populated Excel model on your screen. The whole process takes about 5-10 minutes.

Step 1: Find your property

On the Archer web app (app.archer.re), use the property search bar in the top left. Type an address or property name.

If the property exists in Archer's database, click on it. If not, the search will create a new property record.

Once on the property page, check the property attributes (unit count, class, year built). Click "Edit" to correct anything — accurate attributes improve your comp data.

Step 2: Start the underwrite

Click Run Underwrite (green button, top right).

A modal appears with:

Financials file: Click "Upload new T12" and select your file. You can upload multiple T12s at once for multi-year history.
Rent roll file: Click "Upload new rent roll" and select your file.
Chart of Accounts: Select your COA (Archer Standard or your custom COA if you have one).
Model: Select which model to use (Archer Standard or your custom BYOM model).

Click Run Underwrite.

Step 3: Review the rent roll mapping

Archer extracts your rent roll and presents the mapping for review:

Header mapping: The left column shows Archer's standard fields (unit type, bed, bath, square feet, etc.). The middle column shows what Archer matched from your rent roll. Green means a match was found. If something is wrong, use the dropdown to select the correct column.

Charge code mapping: Archer maps every charge on the rent roll (lease rent, parking, pet rent, etc.) to its standard charge codes. Review these — if "parking storage" should actually be "amenity fee," change the dropdown.

Floor plan mapping: Confirm bed and bath counts for each floor plan. Red cells mean Archer needs you to fill in missing data — it won't let you proceed until beds and baths are confirmed. This is also where you can set renovation status (classic, partial, renovated) using the dropdown or bulk edit.

Click Next after each step.

Step 4: Review the T12 mapping

Subtotal verification: Archer identifies what it thinks is total revenue, total expenses, and NOI. The green bar at top confirms they reconcile (revenue minus expenses equals NOI). If something's off, use the dropdowns to select the correct subtotal rows.

Line item mapping: Every line item from the T12 is mapped to your Chart of Accounts. Archer's AI does this automatically based on what it's learned from 130,000+ line items. Review the yellow column — that's where your COA category is assigned.

If a line item is mapped incorrectly, use the dropdown to change it. Archer learns from your correction for next time.

Yellow-highlighted monthly cells indicate outlier values — amounts outside the normal variance range for that line item. This is informational, not an error.

Click Next when the mapping looks correct.

Step 5: Generate your model

Click Finish and Run Underwrite. Archer compiles everything — your parsed rent roll, mapped T12, rent comps, expense comps — and pushes it into your Excel model. This takes about 60 seconds.

Click Download when it's ready.

Step 6: Open and explore your Excel model

Open the downloaded file. You may need to click "Enable Editing" and enable macros.

The model opens to the Start Here tab. From here:

Rent Roll Analysis: Your parsed rent roll data, floor plan summaries, and analytics
Financials: Your mapped T12 data with dropdowns to make further adjustments
Rent Comps / Expense Comps / Sale Comps: Comps pulled from Archer's database plus any custom comps you've built
Your model tabs: Your pro forma, assumptions, cash flows, and outputs

Step 7: Save to Archer

When you're done working, hit Save to Archer on the Excel ribbon. This saves your underwrite to the web app, trains the mapping AI, and updates your comps.