Description

Why choose this large 8 x 20 model for your outdoor workspace?

As one of the largest of our premium fully insulated garden rooms, the 8 x 20 Shire Fortis provides a mammoth outdoor workspace that actively defends against harsh seasonal weather. Engineered with a robust 72 mm total thickness wall profile, this structure combines an 11 mm LP® engineered wood cladding board on the exterior with an 11 mm engineered wood interior lining board. Supported by an 11 mm engineered wood base panel, a heavy-duty 12 mm marine plywood structural subfloor, and 44mm x 70mm pressure-treated timber floor bearers, these insulated garden buildings provide an incredibly stable foundation. The exterior 11 mm LP® engineered wood cladding board is treated using a zinc borate-based process, presenting primed external walls that give you the freedom to apply your own final colour.

What are the main benefits of the thick SIP panels?

Building your space with SIP panel garden rooms ensures exceptional thermal efficiency, preventing rapid temperature drops inside your cavernous SIP garden office or SIPs shed. The walls and floor both utilise a dense 50 mm EPS-PLUS high-efficiency insulation core, whilst the roof upgrades to a staggering 100 mm EPS-PLUS thermal insulation core sandwiched between dual 11 mm engineered wood structural panels, creating a massive 122 mm total thickness roof construction. This closed-cell 50 mm and 100 mm EPS-PLUS insulation helps regulate the internal climate of your SIP garden rooms, significantly reducing heating costs during winter months. As dependable insulated garden rooms, the tightly bonded structural insulated panels create a highly rigid frame that defends against wind deflection and structural warping.

Can I customise the door position on this 20-foot model?

You can freely alter the door position on these SIPs garden room kits to ensure convenient daily access, no matter how you position the 20-foot length across your garden layout. As standard, this model features the end door positioned on the left side, with light from the steel-reinforced uPVC double-glazed opening windows filling the space. However, you can easily opt for an end door right side, front door left side, or front door right side during checkout. This unparalleled adaptability makes it an excellent SIP workshop kit, ensuring easy access regardless of where the SIP kits are erected within your outdoor boundary.

What are the best ways to utilise this massive 8 x 20 space?

An insulated garden workshop of this magnitude provides a highly versatile, weatherproof footprint that easily adapts to dual or multi-zone professional uses. Many buyers partition the enormous 8 x 20 interior to create a dedicated remote working environment on one side and a lounge or meeting area on the other. You can safely store expensive equipment beneath the premium exterior EPDM rubber membrane waterproofing and 122 mm total thickness roof construction, keeping electronics dry and secure. Furthermore, the heavy-duty 12 mm marine plywood structural subfloor resting on 44mm x 70mm pressure-treated timber floor bearers comfortably supports the weight of heavy fitness equipment, large drafting tables, or machinery, making it an ideal year-round creative space backed by a 10-year anti-rot guarantee.

What advanced technology protects the exterior cladding and access points?

Our 11 mm LP® SmartSide® engineered wood cladding relies on the sophisticated SmartGuard® process for ultimate defence. This includes zinc borate treatment, water-resistant waxes, advanced binders and resins, and a tough resin-saturated surface overlay. It presents a highly authentic embossed wood-grain surface without any of the natural weaknesses of real wood. Additionally, the building features top-tier steel-reinforced uPVC doors equipped with a secure multipoint locking system. By choosing these steel-reinforced uPVC doors and windows, you benefit from substantially improved resistance to swelling and distortion and a much reduced requirement for seasonal adjustment compared to standard timber joinery.

How does the climate control compare to a heavy-duty log cabin?

Surprisingly, the tightly packed 72 mm total thickness wall construction rivals the insulation of roughly 200mm of solid softwood log walling, providing a warmer space without eating into your internal room dimensions. The structural integrity guarantees fewer gaps and potential draught paths to keep the heat locked in. The walls feature a heavy-duty structural OSB internal face for mounting tools, while the 72 mm insulated floor system actively prevents the cold-floor effect commonly experienced in conventional timber workshops. The building is capped with a 122 mm total thickness roof construction clad in an EPDM rubber roofing system, ensuring long-lasting weatherproofing because it does not become brittle in the same way as many traditional mineral-felt coverings.

What is the flooring made of, and how should the base be prepared?

Designed for heavy traffic, the 72 mm insulated floor system is constructed with an industrial-grade 12mm plywood with an EN 314-2 Class 3 exterior bond, supported by treated 44mm x 70mm pressure-treated timber floor bearers. For a valid warranty and maximum lifespan, you must prepare a level, free-draining base with the specified damp-proof separation and underfloor airflow. The rigid panel design allows for a much faster and more accurate assembly process from start to finish. Finally, the sleek low-pitch roof design is expertly trimmed with high-quality fascia and roof-edge finishing components to ensure water runs off efficiently.

Features:

Wall Construction (72 mm total thickness):

• Exterior: 11 mm LP® engineered wood cladding board
• Core: 50 mm EPS-PLUS high-efficiency insulation core
• Interior: 11 mm engineered wood interior lining board

Floor Construction (72 mm total thickness):

• Top Layer: 12 mm marine plywood structural subfloor
• Core: 50 mm EPS-PLUS insulation core
• Underside: 11 mm engineered wood base panel
• Substructure: Supported by 44mm x 70mm pressure-treated timber floor bearers

Roof Construction (122 mm total thickness):

• Covering: Premium exterior EPDM rubber membrane waterproofing
• Core: 100 mm EPS-PLUS thermal insulation core sandwiched between dual 11 mm engineered wood structural panels (top and ceiling)

Windows - Steel-reinforced uPVC double-glazed opening windows

Doors - Steel-reinforced uPVC doors

Treatment - Zinc borate-based process with primed external walls, with the freedom to select the final exterior colour

Guarantee - 10-year anti-rot

About Your Order

The Shire Fortis range is made in the UK with sustainably sourced timber. You get a top-quality timber with a low carbon footprint made from ethically sourced materials. The clean and straightforward design makes it easy to assemble, please note that the fixtures and fittings required are not included as part of your order. The buildings has a 10-year anti-rot guarantee and a 12-month manufacturer's warranty to enjoy it for many seasons.

Garden Office Aftercare:

The home garden office workshop has been treated using a proprietary zinc borate-based process. The exterior is supplied factory primed and ready to receive compatible exterior-grade paint with the freedom to select the final exterior colour choice. Light general maintenance required with the customer to apply final top coat with suitable roller. 

About Shire

Shire is one of the UK's leading manufacturers of garden buildings. It is the proud manufacturer of the most extensive UK timber garden building range, which includes Garden Sheds, Log Cabins, eco homes, Home Offices, Sheds, Workshops, Summerhouses, Playhouses, Arbours, Storage units, and Pet houses.

Their UK production facilities cover 23 acres, including stock holding facilities and an advanced high-speed timber planing mill. There is also a modern, well-equipped joinery production facility and semi-automated production lines. All Shire garden buildings are manufactured in the UK using the finest spruce timber, imported directly, and manufactured using the most up-to-date machines to ensure the best quality and best value for money garden sheds in the UK.

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Delivery

We provide FREE delivery to most mainland UK postcodes; however, certain regions might have an additional surcharge, and a few postcode areas are outside our coverage. To verify availability and potential surcharges, please use the 'Delivery cost checker' tool above with your postcode.

Delivery and Installation Timeframes

We offer same-day delivery and installation services. While we strive to complete the installation on the same day, larger buildings may require more than one day for installation. You can find the estimated delivery and installation lead time for this product on the product page above. Our lead times are calculated in working days (Monday - Friday) and do not include Bank Holidays. These estimates are sourced from the manufacturers and serve as a general guideline, subject to fluctuations in demand. We provide this information in good faith to represent the expected delivery during that period. Please note that some remote areas might experience slightly longer lead times.

Booking Delivery and Installation

By entering your postal code in the ‘Pick a delivery day. ENTER POSTCODE’ Box above you can select a delivery/installation date. 

Delivery and Installation Procedure

Within five working days, Shire, the manufacturer, will contact you via text message or an automated phone call. If a mobile number is unavailable, the automated call will be used. This message will include a link to shire’s website where you can review and accept the installation terms and conditions. To avoid delays, it is essential to promptly review and agree to these terms.

After you accept the terms, Shire will contact you within the specified period to schedule the delivery and installation of your order. Please be aware that during peak seasons, this process may take additional time.

For the installation, the team will require:

• Unobstructed external access to your garden.
• At least 18 inches of clearance around the building.
• A solid, level foundation.

Important Note: The installation team cannot carry the building through your home, garage, or any other type of dwelling.

Delivery Day

The manufacturer, Shire, handles the delivery process. Typically, this item will be delivered using a 17-ton flat-bed vehicle, similar in size to a council refuse lorry. Deliveries are scheduled within the time frame of 7 am to 7 pm."

Specification

Quickview

The large 8 x 20 Shire Fortis Insulated Workspace & Garden Office delivers a highly thermal, expansive structure designed specifically for professionals demanding a massive, dependable year-round outdoor work environment. Serving brilliantly as an insulated garden office or a sprawling insulated garden studio, this premium building offers unparalleled temperature regulation and a customisable entryway layout to complement your plot. Key features include:

• 72 mm total thickness wall construction: Defends against the harshest seasonal weather to maintain a stable internal temperature across your insulated garden buildings.
• Premium exterior EPDM rubber membrane waterproofing: Completely seals the enormous 122 mm total thickness roof construction to keep your interior space bone dry.
• Steel-reinforced uPVC double-glazed opening windows: Enhances natural light across the 20-foot length whilst providing excellent thermal efficiency and security.
• Various entryway layouts: Opt for different steel-reinforced uPVC door positions during checkout to perfectly suit your garden boundary.