Outdoor Garden Buildings
Base work and building construction
The base work for these buildings is mess free and does not require us to do any digging or laying of cement. What we use are ground screws, there are a set number we must use depending on the building size. At Window Systems Ltd, the first thing we must do is a utility services and water pipe survey – if any are found these would need moving first or we would need to relocate the siting of the building.
Watch the video to see how this is done:
Insulated walls
Grained effect wood composite encapsulated in a co-extruded high polymer skin providing an impermeable layer of protection from staining, scratching, mildew and fading.

55% recycled timber 35% recycled PVC polymer
Skinned / co-extruded system
3x times more thermally efficient than traditional timber garden building
Embossed woodgrain effect
Rich authentic wood tones with dual finish options
Low maintenance
Thermally efficient to use your Garden Building all year round
No plastering or decorating as the walls are self-finished
Highly Insulated Walls
Our low maintenance, authentic timber grain effect walls are available in a range of single and dual colour options
Insulated roof
Fully Insulated Roof
Engineered timber roof featuring 100mm insulation panels and proven high performance EPDM BBA certified rubber membrane
Engineered lightweight timber roof trusses
EPDM Coating with a life expectancy of at least 50 years
One piece roofing sheet – no joints – no leaks
Maintenance free
100mm cellular insulation
Sedum Roofs available
Sedum Roof
Sedum Roofs are often referred to as green roofs or living roofs, are a remarkable addition to your Composite Garden Building or Granny Annex.
These unique roofing systems bring the beauty and benefits of nature to the very top of your structure, turning your outdoor space into a captivating, eco-friendly area.
A Sedum Roof consists of a carefully designed and cultivated layer of low-growing, drought-resistant sedum plants, which thrive in the rooftop environment. These plants are chosen for their ability to flourish in a shallow, well-drained growing medium, making them a perfect choice for your garden building.