The biggest mistake new exterior cleaning contractors make is treating a house wash like a concrete driveway. You cannot blast vinyl siding or delicate Dryvit stucco with 4,000 PSI. If you do, you will inject water behind the siding (causing massive hidden mold damage) or blast holes straight through the stucco. House washing is entirely a game of chemistry, known as soft washing. And because it relies on expensive chemistry, quoting it requires extreme precision.

If you guess the price of a house wash from the street, you risk underestimating the gallons of Sodium Hypochlorite (SH) required. This guide reveals how to quote soft washing jobs perfectly using remote satellite estimation.

Phase 1: Calculating the Linear Perimeter

When you wash a house, you are washing the vertical walls, not the roof footprint. To determine how much siding you need to wash, you first need to find the linear perimeter of the house.

Using RemoteQuoter, pull up the residential property. Use the line-measurement tool to trace the entire outer boundary of the house structure. Let's say the tool tells you the house has a perimeter of 250 linear feet.

Phase 2: Estimating Vertical Height via Street View

A linear footprint is only half the equation. A 250-foot perimeter on a single-story ranch house requires drastically less chemical than a 250-foot perimeter on a towering three-story colonial.

Drop into the Google Street View pane within the software. Look at the front elevation.

Single Story: Assume 10 feet of vertical height to the eaves.
Two Story: Assume 20 feet of vertical height.
Three Story: Assume 30 feet of vertical height.

If Street View shows a standard two-story house, your math is simple: 250 linear feet × 20 feet high = 5,000 square feet of vertical siding. You now have a hyper-accurate baseline for your quote.

Measure linear perimeter instantly.

Stop walking around houses. Trace the perimeter from the sky and quote in seconds.

Start Quoting Now

Phase 3: Material Identification (Vinyl vs. Stucco vs. Brick)

Not all substrates are created equal. While in Street View, you must identify the material.

Vinyl Siding: Extremely easy to clean. A standard 1% SH mix applied via downstream injection will melt the green algae instantly. You can price this aggressively (e.g., $0.10 to $0.15 per vertical square foot).

Stucco & Dryvit: Highly porous. A 1% mix might not touch deep-rooted algae in the pores. You may need to run a hotter 2% or 3% mix through a dedicated 12-volt system. Because you are using three times the chemical, you must charge more (e.g., $0.20 to $0.25 per vertical square foot).

Brick: Often requires multiple applications and heavier rinsing. By identifying these materials remotely, you ensure your chemical costs are perfectly aligned with the contract price before you ever arrive on site.