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Mansard – 12′ x 20′ Detached One-Car Garage


The Mansard – A traditional practical design, this 12′ wide x 20′ deep traditional style one-car garage features 21″ overhangs, rough stucco siding beneath a mansard roof and 200 square feet of finished interior floor space.


Mansard – 12′ x 20′ Detached One-Car Garage

Mansard – 12′ x 20′ Detached One-Car Garage

Mansard Detached One-Car Garage Blueprint
Driveway approach

This 12′ x 20′ Mansard style detached one-car garage blueprint package is a contemporary styled and very popular garage plan from our bestselling Mansard Collection

Featuring a rough finished stucco cladding, 21″ deep overhangs, large casement windows and an 8′ wide x 7′ tall overhead door. These two-car garage plans make for easy permitting in places like Vancouver & Calgary.

Quick Facts

Mansard – 12′ x 20′ Detached One-Car Garage

The Exterior:

Mansard – 12′ x 20′ Detached One-Car Garage

The Mansard-style detached one-car garage blueprint package is a classically styled example of form follows function.

With the roof form driving the name, the same is true for its architectural design. The roof combines a 12:12 sloped roof with a small flat portion on top, allowing for the look of a heavy sloped roof garage with the benefits of reduced building height.

This unique roof structure offers an opportunity for storage in a small attic-style storage area above the garage parking, depending on your municipality.

This garage plan is available in a one, two and four-car option. If you’re looking for something similar without a flat roof, look at the  Elizabethan garage.

Measuring 12′ wide x 20′ deep, this generically styled garage features a 240 sf footprint and about 200 sf of finished interior space. The 21″ roof overhangs provide valuable protection from the elements while a central roof drain scoops away water into your two-pipe drainage system or rock pit.

Perforated aluminum soffits help decrease costs, while wall-mounted compact fluorescent lights are used rather than recessed soffit lighting. Several casement windows provide plenty of natural light to the interior. The rough finish stucco cladding with a complete rain screen provides a durable and aesthetically pleasing finish you can rely on.

Flat Roof of the Mansard Detached One-Car Garage Blueprint
Flat Roof of the Mansard Detached One-Car Garage Blueprint

The Interior:

Mansard – 12′ x 20′ Detached One-Car Garage

On the interior of this detached one-car garage blueprint, you have a painted drywall finish with two parking stalls; each measuring 18′-8″ deep x 9′-4″ wide.

Access to the garage comes from a dedicated garage entrance off a 36″ wide side entrance door or through the 9′ wide by 7′ tall rolling overhead garage door.

The Mansard 12′ x 20′ detached one-car garage has a finished floor-to-ceiling height of 9′-0″, thus leaving some room to amend the plans to a 7′ tall overhead door if you so choose. Windows are placed at 42″ above the concrete floor, making a workbench fit nicely beneath.

Ceiling-mounted compact fluorescent lights are typical inside, with ample wall receptacles specified off of a dedicated 60 AMP electrical sub-panel.

Have You Seen These Plans?

This Plan Package Includes:

Mansard – 12′ x 20′ Detached One-Car Garage

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Mansard – 12′ x 20′ Detached One-Car Garage
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Adaptive House Plans will happily exchange your first order for another blueprint or house plan package of equal or lesser value within 30 days of your original date of purchase.

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Mansard – 12′ x 20′ Detached One-Car Garage

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Mansard Detached One-Car Garage Blueprint
Adaptive House Plans
Adaptive House Plans & Blueprints is available to help you with all your questions. Please take the time to contact us if you have any questions at all.

Adaptive Plans Inc.

Product Line

Parking Stalls

1 Stall


12'-0" (3.66m)


20'-0" (6.10m)

Building height

Under 4m (13.12ft), Under 5m (16.40ft), Under 6m (19.68ft), Under 7m (22.97ft), Under 8m (26.25ft), Under 9m (29.52ft)


240 sf

Square Footage

200 sf

Interior Ceiling Height

9 Feet

Vaulted Ceilings


Garage Door Width

8 Feet

Garage Door Height

7 Feet



Climatic Zone

BC – Zone 4, BC – Zone 5 to 7a, BC – Zone 7b & 8

Cladding Type

Acrylic Stucco Siding

Roof Style

Mansard Roof

Roof Slope

12:12 Slope, No Slope

Roof Structure

Engineered Trusses

Roofing Material

Asphalt Shingle Roofing, Synthetic Torch-on Roof Membrane

Roof Overhang

21 Inches

Number of Windows

2 Windows



Covered Entry




Construction Details

Electrical Plan, Footing Detail, Foundation Plan, Reflected Ceiling Plan, Soffit Detail

Structural Engineering Included



24"x36" Architectural Bond Paper, CAD File, PDF File

Pottery Studio


Scratch Set



30-day Satisfaction Guarantee


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