Pre-Slab Floor Plan Walkthroughs: Walk Your Slab Before You Pour It

Big Floor Plans prints your floor plan at true 1:1 scale on a durable synthetic sheet that ships folded in a box. Lay it on the building pad before the pour, and the owner, builder and plumber can stand in every bathroom, check the kitchen and laundry, and see how the house sits on the lot while drains and stub-ups can still move. Printing is $0.45 per square foot with a $100 minimum: about $675 for 1,500 sq ft, $900 for 2,000 sq ft and $1,125 for 2,500 sq ft, before shipping. Price your plan

Why before the pour

Once concrete is placed, moving a toilet, a floor drain or a shower means cutting the slab. Before the pour, it means changing a drawing. A walkthrough moves one more round of review to the cheapest moment. Why earlier changes cost less

What to walk on the pad

Plumbing: toilets, sinks, showers, tubs, kitchen, laundry and floor drains against the room layout
Bathrooms, kitchen and laundry: fixture spacing, island clearances, appliance doors, door swings
Garage and entry: the approach, door locations and the walk inside
Orientation: which rooms face the view, the sun, the street and the neighbors

A walk that turned a house 60 degrees

Big Floor Plans customer Sam Derrickson laid out his slab-on-grade home on the lot in Illinois and realized the house needed to sit nearly 60 degrees differently from what he’d pictured from the drawings. The walk also helped him settle the garage approach and plumbing questions with his team before the slab. Results are project-specific.

Custom homes, barndos, ADUs and light commercial

The same pre-pour walk works for production and custom homes, barndominiums, ADUs and aging-in-place homes. Commercial and light-industrial teams use it for equipment footprints, drains and service areas. Equipment layouts

How it works

Send a scaled PDF exported from your design software; vector PDFs print sharpest.
Approve the digital proof, typically ready in about 48 hours.
Production takes 5 to 7 business days after approval; FedEx Ground shipping is extra. Count back about 2 to 3 weeks from your pour date.
Walk it on the pad, mark questions, and get approved changes into the plans before the pour.

What the print doesn’t do

It doesn’t locate plumbing in the field, set the building on the lot, or replace surveying, foundation engineering or inspections. On post-tension slabs it doesn’t show tendons or approve penetrations; that stays with the structural engineer. Once dimensions are settled, a concrete calculator can help with a rough volume estimate.

For homeowners · For builders · Full-scale spatial validation · Spatial risk score · Rework exposure calculator · Research

Updated October 2026.