Forest Xtend 3.0 Insulated Garden Office 2.98m x 2.9m (97mm)

Overview

The Forest Xtend 3.0 is a premium insulated garden office designed for year-round use. With 60 square feet of multi-purpose living space, this timber garden building is perfect for home working, a gym, hobby studio, or family living area. Built using cutting-edge Structural Insulated Panels (SIPs), the Xtend 3.0 delivers exceptional energy efficiency and comfort in all seasons.

Key Features

• Fully insulated walls, roof and floor for year-round comfort
• 177mm total wall thickness including SIPs, external cladding, internal cladding and cavity space
• A-rated double glazing throughout with toughened safety glass
• Energy efficiency rated Category C (potential to increase to B with solar panels)
• 50-year EPDM rubber membrane roof with 15-year structural guarantee
• Pre-painted interior ready for your choice of colour
• Fully glazed entrance door with adjacent full-length window panes
• Side full-length pane with quarter-height opening window
• Reinforced uPVC door frame with 7-point security lock

Construction

Forest Garden brings over 50 years of expertise to this innovative garden building. The Xtend 3.0 uses Structural Insulated Panels throughout – a high-performance material used in modern energy-efficient homes.

Wall Construction

Each wall SIP contains 75mm of insulation between two sheets of oriented strand board (OSB), creating a 97mm thickness. External cladding uses 15mm premium kiln-dried tongue and groove timber supported by 28x28mm framing. This interlocking structure provides superior weather protection and a contemporary finish. The internal cladding is pre-cut MDF with a vertical beaded profile, primed and ready for painting.

Floor and Roof

Unlike most garden offices, the Xtend 3.0 insulates the floor and roof, not just the walls. The floor SIP measures 108mm thick and is supported by wrapped floor bearers to prevent rot and damp. The floor is left uncovered, allowing you to add your choice of carpet or laminate flooring.

The roof SIP is 122mm thick and features an EPDM rubber membrane covering. This superior material comes with a 50-year guarantee, resists moss and algae growth, and requires no maintenance. Modern anthracite grey fascias complete the professional appearance.

Doors & Windows

The garden office features a fully glazed entrance door with 2 full-length adjacent window panes, plus a side full-length pane with a quarter-height opening window. All frames are uPVC 5-chamber specification with anthracite grey exterior and smooth white interior finish.

Double glazing is A-rated throughout with toughened safety glass for heat and noise insulation. The door frame is reinforced with a key-operated 7-point multi-lock featuring a Ultion three-star security barrel. The opening window is also lockable. A discrete window vent helps maintain a pleasant working environment.

Dimensions

• Length: 2.98m
• Width: 2.9m
• Total living space: 60 square feet
• Wall thickness: 177mm (including all layers)
• Floor SIP thickness: 108mm
• Roof SIP thickness: 122mm

Treatment & Guarantee

The timber is supplied untreated and requires treatment upon assembly and annually thereafter. Forest Garden recommend Sikkens Cetol HLS Plus, Restol Wood Oil, Timmersol ETS Double Protectant, Osmo Country Colour or Osmo Natural Oil Woodstain.

The wooden garden office comes with a 15-year structural guarantee from Forest Garden. The EPDM roof carries a separate 50-year guarantee.

Energy Efficiency

Pre-insulated SIPs ensure warmth in winter and coolness in summer. Combined with A-rated double glazing, the Xtend 3.0 achieves energy efficiency Category C rating, with potential to reach Category B when fitted with photovoltaic solar panels.

Assembly Information

Pre-made SIPs and pre-cut cladding are designed for straightforward assembly. However, if DIY installation isn’t suitable, Forest Garden offers a professional installation service using experienced fitters. The interior battens provide ample space for wiring and recessed ceiling lights should you wish to add mains electrics later.

Delivery Information

Free delivery is available to most UK postcodes, though some remote areas may incur a surcharge. Many garden sheds and offices from Forest Garden offer a free Pick-a-Day delivery option, letting you choose your preferred delivery date. Check the product page for availability.

Optional Upgrades

• Professional installation service
• Solar power options for lighting and electrics
• Photovoltaic solar panels to improve energy rating to Category B

Frequently Asked Questions

Can I add electrics to the Xtend 3.0?

Yes. The interior battens allow space for wiring and recessed ceiling lights. Sheds Direct offers solar power options, or you can arrange for a qualified electrician.

What size is the garden office?

The Xtend 3.0 measures 2.98m x 2.9m, providing 60 square feet of usable space – ideal for a comfortable home office or multi-purpose garden room.

Are other sizes available?

Yes, Forest Garden also offers the Xtend 2.5 and Xtend 4.0 with different dimensions and window/door configurations. Browse our summer houses and garden buildings for further options.

What is the guarantee period?

The garden office includes a 15-year structural guarantee. The EPDM roof carries a separate 50-year guarantee against cracking, splitting or rotting.