Alton Greenhouse | Westminster Cedar Half-Boarded Greenhouse

Make a bold statement in your garden with the Alton Westminster Wooden Greenhouse — a premium cedar-and-glass structure that blends impressive size, timeless elegance, and exceptional durability. At 10’9″ wide with an 11’1″ peak height, the Westminster offers a spacious interior and grand presence, perfect for serious gardeners or anyone looking to create a versatile outdoor retreat.

Crafted from Grade 1 Western Red Cedar with precision mortice-and-tenon joinery and a robust aluminum base frame, this greenhouse delivers superior weather resistance, stability, and insulation. Its half-boarded cedar panels and 3mm toughened safety glass create a bright, airy environment ideal for year-round growing, entertaining, or relaxing. Whether you envision it as a gardening powerhouse, a sunroom, an event space, or a hot tub enclosure, the Westminster offers unmatched versatility and performance.

Premium Construction

• Mortice & Tenon Joinery – Precision-crafted joints add superior strength and make assembly straightforward.

• Western Red Cedar Frame – Naturally rot-resistant, insect-deterring, warp-resistant, and moisture-stable; Grade 1 cedar ensures knot-free beauty and long-term durability.

• Aluminum Base Frame – Elevates wood away from moisture-prone ground areas and allows glass panels to rest directly on metal, preventing common rot spots.

• Thick Glazing Bars – 44x44mm and 44x69mm cedar bars for enhanced stability compared to thinner greenhouse frames.

Distinctive Design

• Oversized Dimensions – 11-foot peak height and wider footprint create an open, airy interior for better air circulation and comfort.

• Classic Cedar & Glass Styling – Elegant half-boarded construction blends seamlessly with any landscape.

• Steep 45° Roof Pitch – Enhances visual appeal and ensures snow slides off easily in winter climates.

• Knee Brace Spandrels – Added at every rafter intersection for exceptional structural strength.

Advanced Growing Environment

• Generous Roof Ventilation – Each roof vent includes an automatic opener that adjusts with temperature changes, no electricity required.

• Louvre Windows – Work with roof vents to draw in fresh air and maintain optimal growing conditions.

• Rainwater Management – Oversized Victorian-style guttering and downspouts allow for efficient collection.

Dimensions & Configurations

• 10’9″ W x 16’8″ L – 179 sq.ft. – 4 roof vents / 3 louver vents

• 10’9″ W x 18’9″ L – 202 sq.ft. – 5 roof vents / 4 louver vents

• 10’9″ W x 20’10″ L – 224 sq.ft. – 6 roof vents / 4 louver vents

Sidewall Height: 5’7″
Peak Height: 11’1″
Frame Color: Natural Wood with Moss Green Aluminum Capping
Warranty: 10 years on framing
Made in the UK

Included in Every Kit

• Complete cedar framing, glazing, and stainless steel hardware

• Base frame and aluminum capping for added water protection

• Hinged inward-swinging door with keyed lock

• Roof vents with automatic openers (varies by size)

• Louver vents with manual openers (varies by size)

• Integrated oversized Victorian gutter system with downpipes

• Ridge decorations and shelving (optional depending on package)

Why Choose the Alton Westminster?

The Westminster isn’t just a greenhouse — it’s a multi-purpose structure that elevates your entire outdoor living experience. Use it as a year-round gardening haven, an elegant outdoor lounge, a hot tub enclosure, or an intimate event venue. If you don’t see the size or configuration you need, give us a call — we’ll help you find or customize the perfect model to fit your vision.

Order the Alton Westminster Wooden Greenhouse today and enjoy a stunning structure that offers the perfect balance of tradition, innovation, and versatility for decades to come.