Plan HG-2708•Duplex / Multi-Gen•70' × 50' Footprint

3,500 Sq Ft (50x70) 3 Bed 2 Bath Duplex / Multi-Gen Floor Plan (STC-60 Mirrored Acoustic Party-Wall Duplex)

3,500 sq ft heated living • 3 Bedrooms, 2 Baths • Free 2D CAD Blueprint (.SVG)

Download Free CAD (.SVG)

Room Dimensions & Zones

70' × 50' Shell

UNIT A SUITE

484 sq ft

21'-6" × 22'-6"

UNIT A BATH

304 sq ft

13'-6" × 22'-6"

UNIT A LIVING

591 sq ft

21'-6" × 27'-6"

UNIT A KITCHEN

371 sq ft

13'-6" × 27'-6"

UNIT B BATH

304 sq ft

13'-6" × 22'-6"

UNIT B SUITE

484 sq ft

21'-6" × 22'-6"

UNIT B KITCHEN

371 sq ft

13'-6" × 27'-6"

UNIT B LIVING

591 sq ft

21'-6" × 27'-6"

Build Cost Estimator

Estimated Cost to Build (70' × 50' Duplex / Multi-Gen)

Region:

Shell / Building Kit

$134,500 – $171,500

Framing package, roof trusses & exterior shell for 3,500 sq ft base.

Owner-Builder

$354,500 – $465,500

Saves ~$159,500 by managing local slab & interior trades.

Turnkey Builder

$514,000 – $625,000

Full general contractor finish including slab, HVAC, kitchen & baths.

Est. Monthly Payment

$2,955 / mo

$455,600 financed (30-Yr)

Down Payment:20%

Interest Rate:6.75%

Free Vector CAD Blueprint • Plan HG-2708

Download 70' × 50' Duplex / Multi-Gen Floor Plan (.SVG)

Scalable 2D architectural vector drawing with exterior and room dimensions, door swings, and fixture layout. Opens in AutoCAD, Illustrator, Inkscape, or any browser.

Material Takeoff & Framing Specifications

Concrete volume (57 yd³), roof surface (~4,247 sq ft), wall framing & architectural notes

Building Package	Specification	Quantity	Est. Range
Structural Shell & Trusses	70'×50' 2x6 Exterior + Double-Stud Insulated Acoustic Party Wall	3,500 sq ft shell kit	$134,500 – $171,500
Concrete Slab & Grade Beams	Monolithic Concrete Slab w/ Dual Sewer/Water Stub-Outs	57 Cubic Yards (4,000 PSI)	$33,750 – $43,000
Roofing & Underlayment	Architectural Shingle or Standing Seam Metal Hip/Gable (5:12 Pitch)	47 Roofing Squares (4,700 sq ft)	$19,740 – $31,960
Closed-Cell Spray Foam / Insulation	3" Closed-Cell Wall & Roof Deck Thermal Envelope (R-21 to R-38)	18,915 Board Feet	$25,535 – $34,993
Windows & Exterior Doors	Low-E Argon Black Architectural Glazing + 36" Fiberglass Entry	4 Windows • 6 Doors	$3,800 – $6,020
HVAC & Multi-Zone Mini-Split	High-SEER2 Heat Pump / Ductless Mini-Split System	7 Ton (84,000 BTU/hr)	$18,200 – $28,700

Exterior Perimeter

240 Linear Ft

Interior Partitions

~245 Linear Ft

Est. Concrete Slab

57 Cubic Yards

Roof Deck Area

~4,247 Sq Ft

Plan HG-2708 (3,500 Sq Ft (50x70) 3 Bed 2 Bath Duplex / Multi-Gen Floor Plan (STC-60 Mirrored Acoustic Party-Wall Duplex)) is an IRC R304/R310-vetted duplex / multi-gen blueprint engineered around a 70'-0" × 50'-0" structural grid (3,500 sq ft base footprint, 0.71:1 Square-Bay Proportion). Configured on the STC-60 Mirrored Acoustic Party-Wall Duplex topology, this layout delivers 3,500 sq ft of conditioned residential living area and 420 sq ft of covered outdoor porch deck.

Inside the conditioned envelope, the floor plan is organized into 8 distinct architectural zones: UNIT A SUITE (21'-6" × 22'-6", 484 sq ft), UNIT A BATH (13'-6" × 22'-6", 304 sq ft), UNIT A LIVING (21'-6" × 27'-6", 591 sq ft), UNIT A KITCHEN (13'-6" × 27'-6", 371 sq ft), UNIT B BATH (13'-6" × 22'-6", 304 sq ft), UNIT B SUITE (21'-6" × 22'-6", 484 sq ft). Plumbing rough-ins are consolidated across UNIT A BATH, UNIT A KITCHEN, UNIT B BATH, UNIT B KITCHEN to minimize sub-slab trenching and manifold pipe runs. Sleeping quarters (UNIT A SUITE at 484 sq ft; UNIT B SUITE at 484 sq ft) are acoustically buffered from the primary living core and positioned on exterior elevations for code-compliant egress glazing.

From a builder takeoff standpoint, the 70' clear-span width utilizes 2x6 exterior + double-stud insulated acoustic party wall bearing on 240 linear feet of 6" exterior wall framing (~244 framing studs/posts) and 245 linear feet of interior partitions. The 5:12 architectural shingle or standing seam metal hip/gable requires approximately 4,247 sq ft of roofing material (47 roofing squares), while the monolithic concrete slab w/ dual sewer/water stub-outs pours at an estimated 57 cubic yards of 4,000-PSI concrete.

Frequently Asked Questions • Plan HG-2708

Building costs, foundation specs, egress & CAD customization questions

How much does it cost to build the 70x50 3,500 Sq Ft (50x70) 3 Bed 2 Bath Duplex / Multi-Gen Floor Plan (STC-60 Mirrored Acoustic Party-Wall Duplex) (HG-2708)?

Based on current national residential construction data for duplex / multi-gen structures, the dried-in structural shell for Plan HG-2708 (3,500 sq ft base footprint) ranges from $134,500 to $171,500 ($40/sq ft baseline). A complete turnkey build—including the 57-yard concrete foundation, 245 linear feet of interior framing, MEP rough-ins for 2 bath(s), and interior finishes across 3,500 sq ft of heated space—ranges from $514,000 to $625,000. Use the interactive Regional Cost Multiplier on this page to adjust for your local labor market and owner-builder sweat equity.

What are the exact room dimensions inside this 3,500 sq ft 3-bedroom layout?

Plan HG-2708 features 8 architecturally solved spaces inside its 70' × 50' footprint: UNIT A SUITE (21'-6" × 22'-6", 484 sq ft), UNIT A BATH (13'-6" × 22'-6", 304 sq ft), UNIT A LIVING (21'-6" × 27'-6", 591 sq ft), UNIT A KITCHEN (13'-6" × 27'-6", 371 sq ft), UNIT B BATH (13'-6" × 22'-6", 304 sq ft), UNIT B SUITE (21'-6" × 22'-6", 484 sq ft), UNIT B KITCHEN (13'-6" × 27'-6", 371 sq ft), UNIT B LIVING (21'-6" × 27'-6", 591 sq ft). Every habitable room meets or exceeds IRC R304 minimum area (70+ sq ft) and minimum horizontal dimension (7'-0"+) requirements.

Can this 70' × 50' floor plan be built with post-frame, red-iron steel, or 2x6 stick framing?

Yes. Because the outer envelope is engineered on an even 70'-0" × 50'-0" structural grid (240 LF perimeter) with clear-span 5:12 trusses, a local structural engineer or building kit supplier can adapt the blueprint for 2x6 Exterior + Double-Stud Insulated Acoustic Party Wall, conventional 2x6 stick framing at 16" o.c., laminated post-frame columns at 8' o.c., or structural insulated panels (SIPs).

What files are included in the free CAD blueprint download for Plan HG-2708?

Downloading Plan HG-2708 provides the high-resolution scalable vector floor plan (.SVG) with crisp architectural lineweights, exterior dimension strings (70'-0" × 50'-0"), room-by-room callouts, door swing arcs, and window schedules, plus instant browser printing for contractor bidding and preliminary municipal zoning review.