Exaco Janssens Modern M34 Greenhouse 10 x 15 ft

The Modern Greenhouse trades the ornamental curves of a traditional Victorian for a clean, architectural shed-roof silhouette. A single-directional glass wall floods the interior with light and opens up unobstructed garden views, making it as much a design statement as a growing space. Crafted in Belgium by Janssens — a family-run greenhouse manufacturer with over 75 years of experience — the Modern combines European engineering with a distinctly contemporary aesthetic, distributed in North America by Exaco.

The frame is built from sturdy 17-gauge tubular aluminum portal frames with extra-strength tubular gutters running along all four sides, giving the structure dependable strength through changing seasons. Every panel is glazed with 4mm tempered safety glass for durability and clarity, finished in a black powder coat (RAL 9005) that reinforces the Modern's minimalist look. The foundation frame is 2.25" wide with corner anchor posts (1.5" x 1.5") that extend 12" below ground for secure anchoring — models 19'11" and longer include an additional anchor pair at the midpoint of the long wall for extra stability.

Climate control comes from a coordinated system of roof vents, a louvre side window, and push-out side windows, positioned so the roof vents exhaust rising hot air while the lower windows draw in cooler air for natural cross-ventilation. Roof vents can be fitted with manual stick openers, heavy-duty manual spindle openers for windy sites, or automatic Ventomax piston openers that respond to temperature. Every model ships standard with a set of double hinged doors, and the layout is flexible — doors and windows can be positioned in any bay of the structure to suit the space, with door placement optimized based on each model's panel configuration.

The Modern line comes in three footprints to fit a range of gardens: the compact M23 (10'2" x 7'9", 79 sq ft), the mid-size M34 (15' x 10'2", 150 sq ft), and the expansive M36 (19'11" x 10'2", 200 sq ft), each with a 15-degree roof pitch and sidewall height suited to comfortable full-height use. Designed for hobby and serious gardeners alike, the Modern Greenhouse works equally well as a dedicated growing space or an inviting light-filled garden retreat — though as with any glass greenhouse, seasonal heat, condensation, and site preparation should factor into placement and use.

• Aluminum frame (17-gauge tubular extrusions, Black RAL9005)
• 4mm tempered safety glass
• Aluminum foundation/base frame
• Rubber seals/gaskets
• Lockable double hinged doors
• Automatic + manual spindle roof vent openers
• Louvered window(s) with manual opener
• Push-out side windows
• Gutters and downspouts
• Hardware (bolts, brackets, anchors)

Build and materials

Brand: Janssens, distributed by Exaco, manufactured in Belgium

Frame: 17-gauge tubular aluminum extrusions, powder-coated Black (RAL 9005)

Wall glazing: 4mm tempered safety glass

Roof glazing: 4mm tempered safety glass

Roof pitch: 15°

Foundation: Integrated aluminum base frame, 2.25" wide, with corner anchor posts (1.5" x 1.5") extending 12" below ground for anchoring

Ventilation

Roof vents: Manual stick opener standard; upgradeable to manual spindle opener or automatic Ventomax wax/oil-piston opener (opens between 68–70°F, no electricity required) — qty 2 per model

Louver windows: Manual opener standard, automatic opener (Sesam Liberty) available as upgrade, with optional winter cover — qty 1 (M23) or 2 (M34/M36)

Roof vent glass dimensions: 28¾" × 32½" (730mm × 825mm)

Performance ratings

R-value: Not listed in source materials

Rainwater collection: Integrated gutters with downspouts, standard on all models

Wind/snow load ratings: Not formally rated; manual notes optional reinforcement (self-tapping screws at rafter/ridge/gutter joints, stainless steel turnbuckle cable) for high-snow-load areas

Other

Door: Double hinged doors, lockable, opening width 56¾" (1441mm) for double doors; door placement flexible across any bay

Staging shelves: Optional — Top Shelf (4" wide), 2-Slat Shelf (9" × 59"), 5-Slat Shelf (21" × 59"), Seed Tray/Seedbed (20" wide, 4" planting depth)

Victorian ridge cresting: Not included (clean shed-roof line, no ornamental cresting)

Expandable: Not specified in source materials

Stem wall compatibility: Yes — door extension kit required, max stem wall height 30" with standard kit

Warranty: 15 years on frame

Assembly typically takes 2–3 days with a crew of 2–3 people — this isn't a same-afternoon build, largely due to the glass glazing work and the size of the larger models. Buyers should plan the timeline and labor accordingly, especially if they're coordinating with a foundation contractor beforehand.

Manual

Free shipping to all 48 contiguous states

Delivery time: 8–13 business days

Ships via LTL freight (curbside): liftgate drops the pallet at ground level; plan on 2–3 people to move it from the curb to your install site

Outside the mainland US (Alaska, Hawaii, international)? Shipping terms need to be confirmed separately

Warranty


Damages

Please inspect the packaging of your item(s) upon arrival. If you notice any damage, make note of it when signing for delivery. If your item(s) arrive damaged, please contact us with photos and we will process an insurance claim on your behalf.

Cancellations & Refunds

Orders cancelled after 48 hours are subject to a $20 administration fee, whether or not the order has shipped. If the order has already shipped, the buyer is also responsible for actual return shipping charges. Refunds are issued only to the original credit card used at the time of purchase.

Many of our items are large and heavy, and cannot be returned for buyer's remorse. In these cases, all sales are final.

Returns (RMA)

In certain situations, we will accept a return through our RMA department. The buyer is responsible for full return shipping costs. All returns must be pre-approved by our RMA department before being shipped back.