ADU Pad Prep in Sacramento — Full Sequence
Sacramento ADU pad prep typically starts with removing whatever occupies the rear yard — a detached garage, an old pool, or accumulated debris — and ends with a compacted, graded pad matched to the foundation plan. We do the full sequence.
- Existing structure removal (garage, pool, shed) if present
- Slab removal or leave-in-place depending on structural engineer spec
- Rough excavation to pad subgrade elevation
- Subbase import and compaction (aggregate base or engineered fill per soils report)
- Compaction testing — nuclear gauge or sand cone to confirm spec
- Finish grade to foundation plan elevation
- Documentation for permit close-out and foundation inspection
Sacramento Clay Soils and Compaction
Sacramento Valley clay loam is expansive — it swells when wet and shrinks when dry. Pad prep on clay requires careful moisture conditioning before compaction to achieve consistent density. Building a foundation pad on improperly compacted clay leads to differential settlement.
- Native clay loam may need moisture adjustment before compaction — too dry or too wet both fail
- Compaction spec for ADU foundations typically 90–95% Modified Proctor
- Import aggregate base (Class II or Class III) recommended for pad subbase over clay
- Subbase depth determined by soils report — typical 6–12 inches over compacted native soil
- Compaction tests documented and provided with project close-out
- Structural engineer or geotechnical engineer may specify over-excavation and recompaction on older lots
Sacramento Neighborhoods with Highest ADU Pad Prep Volume
Pad prep demand in Sacramento is concentrated in older in-fill neighborhoods where rear yards have space and ADU projects are already in the permit pipeline.
- Land Park — detached garage removals, tight lots, alley access
- Curtis Park — similar to Land Park, heavy ADU activity
- East Sacramento — mix of garage removal and pool conversion pads
- Tahoe Park — 1950s lots, original gunite pools common, high pool-to-pad conversion volume
- Midtown — tight lots, infill ADUs, GC coordination required
- Natomas — newer construction, less legacy structure removal needed
Frequently asked questions
How much does ADU pad preparation cost in Sacramento?
A typical Sacramento ADU pad prep — garage removal, slab demo, rough grade, subbase compaction, and finish grade — runs $6,000–$18,000. If there's no existing structure to remove, just grading and compaction, the range is $3,500–$8,000. Final cost depends on what's being removed and the foundation spec.
Do I need a soils report for an ADU pad in Sacramento?
It depends on your ADU design and the city's requirements for your specific permit. Many standard ADU designs in Sacramento use prescriptive foundation specs that don't require a separate geotechnical report. Your architect or structural engineer will know whether a soils report is required for your project.
How long does ADU pad prep take in Sacramento?
The physical work — removing structures, grading, and compacting — typically takes 2–5 days depending on scope. The permitting and SMAQMD steps before demolition can add 4–8 weeks to the overall timeline. If there's nothing to demolish first, just grading and compaction can often mobilize within a week.
Can you coordinate with Sacramento's ADU fast-track permit process?
Yes. We're familiar with Sacramento's ADU approval process and can work concurrent with permit review in some cases. We coordinate with your GC or ADU builder and can sequence demo and grading to match the construction timeline. Provide your permit drawings and we'll align our scope to the foundation spec.