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ATT Fabrications Garden Building Anthracite Grey 4370mm Wide x 2540mm Depth

Code: GB ANTH 4200X2550
  • From £10,745.00 (inc. VAT)
  • FREE Delivery
Stocked Item   |   Usually delivered within 5-15 working days
Personalisation (More Info)

PLEASE NOTE: Our installation service is for the erecting of the building onto a suitably sized, square and level base provided by you.  The service includes installing the building, including any doors and windows and the roof, giving a fully finished building externally.  The service does not include any internal finishes, lighting, electrical work or fitting of the insulation (if purchased).  After you place your order we will contact you to request photographs showing access to the site and of the base along with an installation checklist to be signed off. 

ORDER BY PHONE: 01388 817 683

Our Garden Buildings are an affordable way to create extra room. Sometimes moving is not an option or you have no spare rooms available, but just need a little more space. They can be built for multiple uses including and not limited to Home Office, Play Room, Gym, ‘Man Cave’ or ‘She Shed’, Library, Music Room, Pool Room, Gin Bar, Sun Room, Yoga Room, Gaming Room, TV Cinema Room, Salon and of course general family outdoor living!

Our stylish pre-insulated Garden Buildings will give a certain ‘wow’ factor to your garden and enhance any open space. Unlike timber clad buildings, our buildings offer a virtually maintenance free option which include our standard doors and windows (as an option) that comply with building regulations.

Our Garden Buildings are available in a range of standard sizes and several door and window configurations – Should none of our standard sizes meet your requirements please contact us and our in house team will design a bespoke building for you. 

The buildings come as standard with Patent Pending through colour composite cladding which contains no wood fibres or any other organic materials, it will not absorb moisture, won’t rot or split and doesn’t attract insects that can be a nuisance or could damage its fabric. 

We can supply the buildings in a range of colours as below;

Anthracite Grey

Moondust Grey

Soft Green

Oyster White

Pigeon Blue


Please contact us if you would like a building in these colours.

This makes it especially robust, even in the most extreme weather conditions.  The cladding has excellent wind, hail and impact resistance.  Even after years of service, it never needs painting or treating, and all it takes to bring it back to its best, is the occasional light clean with a garden hose.

To complement the cladding we use a specially designed powder coated aluminium corner, end and connecting trims that will not warp, crack or distort. 

The wood-grain embossed Matt finished boards and aluminium trims give a high quality decorative finish.

Our buildings are manufactured using SIP Panels (Structurally Insulated Panels) as used in modern new build homes.  The panels are made up of Oriented Strand Board (OSB) to both external faces with insulation sandwiched between them to form a very strong, ridged and pre insulated wall panel.

The walls, roof and floor are all manufactured the same, meaning that the building is extremely well insulated.  The method of pre-insulating the panels also maximises the space within the building and means it is usable from the day of installation.  The structure reinforced with reinforcing splines with a thermal break or advanced thermal performance or high Grade C24 Timber where required for additional strength.

Internally the buildings have a Timber / OSB finish so once installed are ‘ready to use’ which can be left as the internal finish or there is the option to add a secondary internal finish of your choice. The SIP wall and floor panels are 97mm thick and the roof is 122mm thick.

A 25mm breathable gap and waterproof breathable membrane is then present between this and the external composite cladding giving an overall wall thickness of 130mm.  The system not only gives excellent strength and durability but also excellent thermal and water resistant properties.

We also offer an installation service. Please see our Product FAQ for further information.

Modern SIP Panel construction gives excellent panel thermal performance with a panel U-Value of 0.39W/m2k.
Unique UV-Stable Patent Pending through colour maintenance free composite cladding that will not split / crack or require treatment like normal timber.
Powder coated + Qualicoat Seaside Guarantee Aluminium Corner, Edge and Joint trims that require no ongoing maintenance which also give the buildings a great finish and look.
EDPM rubber roofing kit supplied with contrasting fascia boards.
Full height residential specification doors with a clear opening height of 1870mm (uPVC French Doors), 1866mm (uPVC Bi-Fold Doors), 1920mm (uPVC Sliding Patio Doors)
Colour matched UPVC doors complete with;
    o Steel reinforced profiles 
    o Adjustable hinges (French Doors and Bi-Fold doors only).
    o High Security Multi-point locking system.
    o Internally beaded for improved security.
    o 28mm Double Glazed Toughened Safety glass to BSEN1279 & BSEN12150
    o Exceptional thermal efficiency with low-e Argon filled glass units.
    o Supplied complete with handles, cill and overhead ventilator 
    o Peace of mind that not only are the Buildings manufactured by us but so are the windows and doors.
Supplied with full installation instructions for both the building and the doors.
Components Tested and Comply to BBA T1/04, BSENISO3451-1, BBA T1/07, BSENISO-180, BBA T1/06, BSENISO-2409, BSEN12608 clause 5.8.3, BSEN13245-2 Annex B & C, BSEN1279, BSEN12150.
10-Year product guarantee against warping, cracking & discolouration – terms apply.
Manufactured by us in the UK (including the doors and windows).
Installation service available if required.
FREE UK Mainland Delivery by our 2-person delivery teams.
COVID-19 Update

COVID-19 Update - We are Open and Manufacturing again. 


Like most businesses we closed to reduce the spread of the COVID-19 Virus however as of 15th May we reopened and are manufacturing and delivering using new procedures and adhering to Government Guidelines.  

Our showroom however remains closed until further notice.

Take Care & Best Wishes from all the Staff at ATT Fabrications Ltd

Can you manufacture Bespoke Garden Buildings?

Yes we can.  If you would like to send us some details our in house team can look into different sizes, shapes, doors and building colour options etc for you.

What type of base will I require for my Garden Building?

If unsure, as with all building work, we recommend consulting a builder or similar professional as the best base can vary depending on the type of ground where the building is going to be located.  The most common base used is a concrete slab base but a paved base or other options can also be used. As an alternative option, Ground Screws can be used which can be purchased from ourselves and be fitted as part of the installation.

Are your Garden Buildings easy to assemble?

Our Garden Buildings are supplied with modular, floor and roof panels and the walls are also provided pre-clad so are relatively easy for 2-3 people to assemble.  The floor panels need to be screwed together and the wall panels built around these. The roof will then be into place in sections and then the rubber roof needs to be fitted. Any fascia and finishing boards / trims are supplied oversize and are cut and fitted on site.  The doors are from our standard door range that we have been manufacturing for over 10 years so are well proven for ease of installation. All fixtures and fixings that should be required to assemble the building are included.

How will my Garden Building be delivered?

We use a 2-person delivery team to deliver your building and you will be contacted by phone or email to arrange your delivery. The building base, walls and roof all come in prefabricated sections.  The walls are pre-clad where possible although a few lengths may need to be fitted to the front to avoid joins above the doors.  The roof also comes in sections and the EDPM rubber roof will be delivered beforehand direct from our supplier.  The fascia and trim boards are supplied oversize and need to be cut and installed onsite.

Do I need planning or any other form of permission for my Garden Room?

As our Garden Rooms are below 2.5 meters in height planning permission is usually not required to locate one at the rear of your property provided you are not located in conservation areas etc.  We always recommend however that with any building work or additions / alterations to your home that you always check with your local planning office.  More useful information on planning can be found at the Planning Portal link below for Out Buildings.

It is important to avoid planning permission that the overall building height including base is not over 2.5 meters so take care with the height of your base.


What sort of applications can I use my Garden Building for?

Anything and Everything!!!  We get enquires for Garden Rooms for a whole host of uses including but not limited to, Home Office, Play Room, Gym, ‘Man Cave’ or ‘She Shed’, Library, Music Room, Pool Room, Gin Bar, Sun Room, Yoga Room, Gaming Room, TV Cinema Room, Salon and of course General Family Outdoor living.

Do you manufacture the Garden Buildings?

Yes we do!  We have a large production facility in Co. Durham in the North East of England where not only do we manufacture the Garden Buildings, but we also manufacture the doors and windows that are used in them along with all the other products on our website.

Do you have a Showroom?

We have a showroom in our factory in Co. Durham in the North East of England showing a range of Garden Buildings and the doors we manufacture.

What kind of internal finish can I put on my Garden Building Walls and Ceiling?

We supply the buildings with an OSB finish internally. This can be left as a final finish or you can add plaster board, Grooved MDF panels, various types of cladding or decorative panelled sheets etc.

What maintenance will be required on my Garden Building?

As we fully clad our Garden Buildings with composite through colour boards with powder coated aluminium edge trims that will not warp, split or require treatment etc. like conventional wood, our Garden Buildings are virtually maintenance free.  It is recommended that you ensure the buildings are on a suitable base and not left in standing water or wet ground and that there is always adequate air circulation and that any nearby trees or shrubs etc. do not start to grow into or onto the building.

Do you offer electrics?

Due to the large variety of electrical requirements and locations of switches and sockets etc. we do not offer electrics.  Any suitably qualified Electrician would be able to assist you with your personal requirements.

Can you install my Garden Building?

We can supply only, or supply and install your garden building. Our installation service is for the erecting of the building onto a suitably sized, square and level base provided by you, unless you choose for us to supply and fit Ground Screws at the same time as installing the building.  The service includes installing the building, including any doors and windows and the roof, giving a fully finished building externally.  The service does not include any internal. After you place your order, we will contact you to request photographs showing access to the site and of the base along with an installation checklist to be signed off. If you decide to install yourself, the buildings are supplied so they can be installed by competent DIY customers with suitable help as it’s a 2-3 person job due to the size and weight. If you are not comfortable installing your base and Garden Building yourself suitability qualified Joiners, Builders or similar trade’s persons will be able to assist.

Why should I choose your Garden Building?

We are a long-established company trading for well over 10 years and manufacture all our own products all of which come with a 10 Year Guarantee.  Our Garden Buildings come with unique external through colour composite cladding and powder coated aluminium trims.  The composite cladding and trims are not only unique but also will not split, warp and attract moss like normal timber making them virtually maintenance free.

Please see our full delivery terms and conditions page (link below) for our COVID-19 updated delivery terms and conditions.

Delivery is to any mainland UK address using a specialist Home Delivery Company who we have worked in partnership with for many years.  Unlike a normal 'courier' our Delivery Team will contact you by phone to arrange a suitable delivery date.  The day before the delivery where possible the driver will be in touch again to give a better indication on the time of your delivery.  The two man Delivery Team will also deliver the product to the location / room of your choice.

If in the unlikely event there are any damages or shortages to your delivery, please in the first instance call or email us within 48 hours to report this.  Please also take photos of the delivery if possible. 

For full delivery and returns terms and conditions please click here

We accept payment by most forms of Credit and Debit Card either via our website or over the phone (01388 817683).

Payment  can also be made by PayPal or Bacs Bank Transfer. 

If the products you require are over the minimum value required you can also apply for our interest free payment plan or one of the credit options.  These are then handled by Deko our Finance provider.

For our full policy, please click here