Cardwell3
The building system

Factory-informed. Site-built where it matters.

The Cardwell3 is engineered as a repeatable product — a SIP-panel building system designed for speed, energy performance, comfort, and consistent quality.

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Independent units per lot
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Defined build phases
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Repeatable system design
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Bedrooms · 6 bathrooms
The 5-phase build

A defined path from lot to handover

  1. Phase 1

    Planning, Permits & Foundation

    What happens

    Site evaluation, design fit to the lot, permitting, utilities, and the foundation system are completed up front.

    Why it's faster

    Front-loading design and approvals on a repeatable plan is intended to shorten the slowest part of most projects.

    Less labor, waste & complexity

    A standardized footprint reduces redesign, rework, and one-off engineering on every build.

    What the owner sees

    Approved drawings, a permitted project, and a finished foundation ready for vertical construction.

  2. Phase 2

    Dry-In Shell

    What happens

    Framing, sheathing, roof, windows, and exterior doors go in to make the building weather-tight.

    Why it's faster

    Reaching dry-in quickly protects the interior and lets trades work in parallel, sheltered from weather delays.

    Less labor, waste & complexity

    Repeatable framing packages and pre-planned openings cut measuring, cutting, and material waste.

    What the owner sees

    A recognizable building — walls up, roof on, openings sealed — a clear, photogenic milestone.

  3. Phase 3

    Interior Rough-Ins

    What happens

    Electrical, plumbing, HVAC, low-voltage, insulation, and air sealing are roughed in and inspected.

    Why it's faster

    Coordinating mechanical systems against one known plan reduces conflicts and on-site problem-solving.

    Less labor, waste & complexity

    Pre-coordinated routing means fewer specialized trades reworking each other's paths.

    What the owner sees

    Passed rough-in inspections and a building ready to receive finishes.

  4. Phase 4

    Interior Finishes

    What happens

    Drywall, flooring, cabinetry, fixtures, tile, paint, and trim complete the living spaces.

    Why it's faster

    Standard finish schedules let the same crews repeat a known sequence with predictable quality.

    Less labor, waste & complexity

    Repeatable specifications reduce decision fatigue, ordering errors, and finish-stage waste.

    What the owner sees

    Three move-in-ready units with a consistent, premium interior.

  5. Phase 5

    Furnishing, Commissioning & Handover

    What happens

    Systems are commissioned and tested; the optional furnishing package is installed; the owner is walked through and handed the keys.

    Why it's faster

    A defined commissioning step is intended to confirm comfort, safety, and performance before handover.

    Less labor, waste & complexity

    A productized furnishing package turns a custom scramble into a repeatable install.

    What the owner sees

    A documented walkthrough, commissioned systems, and — if selected — a fully furnished, rent-ready building.

Exploded assembly

One repeatable stack

Foundation → structure → envelope → roof
Exploded assembly

One repeatable stack, layer by layer

Drag to rotate. The Cardwell3 is engineered as a stack of repeatable assemblies — foundation, structure, envelope, and roof — so the same system can be built again and again with consistent quality.

  • Roof & solar-ready shell (SIP)
  • Upper level — bedrooms & bath
  • Main level — living, kitchen, garage
  • Foundation — slab & capillary break
What makes it different

Engineered for productivity, performance, and quality

Construction productivity

A known plan and repeatable assemblies let crews repeat a proven sequence instead of solving a new building every time.

Material efficiency

SIP panels arrive as engineered components, designed to reduce on-site cutting, measuring, and waste.

Energy efficiency

A continuous, well-sealed SIP envelope with mini-split heat pumps is designed to lower conditioning loads.

Factory + on-site balance

Factory-built panels for the envelope, paired with skilled on-site assembly where craft matters most.

Fewer specialized trades

Pre-coordinated mechanical routing is intended to reduce conflicts and rework between trades.

Build repeatability

Designed as a product, so the system can improve and standardize build over build.

Quality control

A defined commissioning step is intended to verify comfort, safety, and performance before handover.

Security

Secure entries and a garage-integrated ADU, planned for modern locks, cameras, and smart-home readiness.

Soundproofing

Assemblies detailed to reduce sound transfer and support privacy across a multi-door building.

HVAC comfort

Wall-mounted mini-split heat pumps plus fresh-air ventilation, designed for quiet, even comfort.

Solar readiness

Roof and electrical planning intended to accommodate photovoltaics where site conditions allow.

Systems

Explore the assemblies

Proven performance

Government-lab-backed airtightness

Independent testing referenced by Oak Ridge National Laboratory found SIP construction dramatically more airtight than conventional framing — the foundation of a comfortable, low-energy home.

~15×more airtight

SIP vs. conventional framing, identical-structure test (ORNL)

~90%less air leakage

vs. a comparable framed structure (Whole Building Design Guide, citing ORNL)

0.8–1.2target ACH50

expected for the Cardwell3 (SIP + HRV/ERV); current U.S. energy code is ~3–5

Airtightness figures reference research performed or referenced by the U.S. Department of Energy's Oak Ridge National Laboratory (ORNL), DOE Building America, the Whole Building Design Guide (WBDG), and the Structural Insulated Panel Association (SIPA). Final airtightness is verified by blower-door testing on the completed building.

Energy & HERS

Built to score low — and cost less to run

SIP homes routinely earn strong HERS Index scores. Here's where the Cardwell3 is designed to land, the DOE envelope finding, and real measured SIP projects for reference.

35–50Estimated HERS Index

vs. ~100 for a code-built home — and 0–30 with solar. Lower is better; an estimate pending a certified RESNET rating.

12–14%Whole-house savings, envelope alone

DOE Building America finding for SIP shells — before solar or heat pumps.

25–50%Lower heating & cooling cost

Comparable SIP + heat-pump + HRV homes vs. code-built, depending on rates and occupancy.

Measured SIP projects (third-party rated)

Real homes built with SIPs, with verified HERS scores — evidence that the envelope delivers.

36HERS · Park Rapids, MNSIP · 0.47 ACH50 · ERV
59HERS · Olympia, WASIP + HRV · ENERGY STAR · 2.5 ACH50
33HERS · Fort Worth, TXSIP · DOE Zero Energy Ready · LEED Platinum

HERS figures for the Cardwell3 are estimates based on comparable SIP projects and DOE/RESNET performance data — not a certified rating. A certified RESNET rater (using REM/Rate or Ekotrope) produces the official HERS Index; final energy and cost savings depend on finishes, windows, HVAC, occupancy, and utility rates.

Built smarter

Luxury feel without luxury waste

Less energy use

A continuous SIP envelope — designed for roughly 30–50% better real-world wall performance than 2×4 framing — is intended to lower conditioning loads.

Less waste

Repeatable specifications and standard cut packages are intended to reduce material waste.

Less material complexity

One refined parts list replaces dozens of one-off decisions.

Fewer specialized trades

Pre-coordinated routing reduces rework between trades on site.

Faster construction cycles

A known sequence lets crews repeat what they already know how to build.

Factory + on-site balance

Factory-built SIP panels for the envelope, paired with on-site assembly where it matters most.

Repeatable production

Designed as a product, so quality and pace can improve build over build.

Bring The Cardwell3 to your city

Three doors on one lot. Designed for family, ownership, and income.