Realistic Costs

Understanding True Building Costs — No Surprises.

Many contractors advertise $200–$300 per square foot. These figures are often misleading because they typically cover only basic building costs and exclude site development, foundations, utilities, permitting, and challenging lot conditions common in our region. At DIGS, we believe in complete honesty from day one. The numbers below reflect realistic all-in costs for well-built projects in the Greater Seattle area (2025–2026).

01 — Real Build Costs

What a real build actually costs.

These are all-in figures for 800–1,000 sq ft projects — design, permitting, site work and construction together, not the stripped-down number that ignores everything below grade. Where your lot lands in the range depends on slope, soils, utilities and finish level.

DADU / ADU01

All-In Range

$375,000 – $600,000+

Per Square Foot$350 – $600+/sq ft

Single-Family Home02

All-In Range

$400,000 – $700,000+

Per Square Foot$400 – $700+/sq ft

Where the dollars go

Every dollar, accounted for.

Typical 800–1,000 sq ft project. The advertised “cost per square foot” almost always hides the first two rows — but on a real Pacific Northwest lot, that's where the surprises live.

CategoryTypical Contribution% of TotalKey Notes

Design & Permitting (Soft Costs)

Typical Contribution$40 – $80 / sq ft

% of Total10–15%

Key Notes

Architecture, engineering, permits, geotech

Site Development & Difficult Lots

Typical Contribution$50 – $150+ / sq ft

% of Total15–30%+

Key Notes

Slopes, ECAs, utilities, grading, retaining walls

Actual Construction (Hard Costs)

Typical Contribution$250 – $480 / sq ft

% of Total70–85%

Key Notes

Foundation through finishes

“DIGS did a fantastic job clearing and prepping our land exactly how we needed. The results look great.”

Joe Bou-ChedidGoogle Local Guide· 5.0 on Google

02 — The Smartest First Step

Start with a Pre-Construction Planning process.

Nearly every expensive surprise on a build traces back to something that could have been discovered before breaking ground. That's exactly what our Pre-Construction Planning Service is for — a focused, paid engagement where we pressure-test the feasibility of your project so your budget is built on facts, not guesses.

We research zoning, Environmental Critical Areas, setbacks, utilities and soils, then hand you a clear feasibility report and a realistic starting price for your specific lot. It is the single best way to protect your investment before the big commitments begin.

What you walk away with