Dunster House Ltd.
Est. 1994
28mm Double Glazing
We don't compromise on quality just because it is a garden building. Our garden offices have domestic style uPVC windows and doors, making your garden office secure and highly insulated. The 28mm sealed double glazing provides improved heat and sound insulation.
Multipoint Locking Windows & Doors
Our garden offices come with domestic grade multipoint locking windows and doors. Great for securing the garden building and its contents! Euro cylinder locks are used in our uPVC doors to ensure maximum safety and security.
Easy to Build Panel System
Using a technique unique to Dunster House, we've been able to create panels that simply slot together, ensuring the rigidity and strength of this office surpasses many alternatives and is quick to build.
Fully Pressure Treated
Our Garden Offices are made using non-toxic, pressure treated timber. This process forces wood preservative deep into the pre-cut timber using a large pressure treatment vat, meaning that there would be no need to spend time treating the timber for years. The timber is treated against fungal decay and insect infestation without any need for the customer to apply treatment during this time.
Tall Door Height
With a walkthrough height of over 6'4" (1.94m) there is no need to duck on the way in. They are probably the tallest doors on the market and great for moving furniture in and out of the office.
Sliding Doors
Why waste precious space with a hinged door? Our doors slide smoothly open and come complete with locking handles, multi-point locking system, Euro cylinder locks and internal beading, for added security. At over 66cm wide our doors give plenty space for people, and by temporarily removing the stops and handle (4 screws) it is also possible to get them up to 80cm wide to cope with the bulkiest furniture.
9 Point Locking System
The contemporary garden offices feature our impressive 9 point door locking system that ensures maximum protection. Featuring three roller cams and three hook bolts, two dead bolts and a latch ensure all the personal belongings are kept safe and secure.
Pressure Treated Bearers
By pressure treating our floor bearers we protect the lowest part of the building from rot and insect infestation. This forces the treatment deep into the timber using a large pressure treatment tank. This costly but effective process ensures there is no need to re-treat the timber in years
Floor Insulation
Our contemporary garden offices feature 70mm thick insulated SIP floor panels that ensure the garden office is kept warm throughout the year. The floor insulation has a U-Value of 0.38 W/m2 which is extremely low, the lower the U-Value the better the material is as a heat insulator.
IzoPanel Roof
Our Garden Offices feature a very advanced roofing system manufactured by IzoPanel. They use a stiff polyurethane foam core (a material that provides a very low thermal conductivity rating) joined together tightly with overlapping cladding in a trapezoidal profile, which makes strong joints that prevent water ingress. Altogether the roof is waterproof, has great thermal characteristics and is uniquely strong.
Moisture-Resistant Walls And Floor
Our unique design hinders moisture buildup inside the office. The walls of our Garden Offices have layers of shiplap cladding, moisture resistant membrane, thermal insulation panels and interior walls of Gypsum Fibreboard, which is also fire-resistant. The Pressure Treated Floor Bearers are covered by a layer of Wood Plastic Composite, followed by layers of insulation and MFP fibreboard. These layers minimize the transfer of moisture through the floor and walls, making this garden office a comfortable working environment all year round.
15mm Shiplap Cladding
Shiplap cladding is named after the old boatmaking technique where the boards overlap. This means that the natural timber can expand and contract with the seasons and not create gaps. The curve or channel of shiplap cladding enables water to run off easily.
Fire-Resistant Inner Wall
The inner walls of our Garden Offices are made using a fire-resistant fibreboard; a hard-wearing made from recycled paper fibres and Gypsum (Hydrous Calcium Sulphate). This Garden Office has increased protection from fire. The fibreboard comes unpainted, but it can be decorated, as it is a good surface for paint and is easy to wallpaper.
Energy Saving Insulation
The walls, floor and roof of our garden offices are all insulated to lower energy costs. We use Polyurethane to insulate our garden offices, which is proven to retain heat better than cheaper alternatives such as polystyrene or rockwool. The U values of our insulation are as follows: 0.64 W/m2 K in the roof, 0.62 W/m2 K in walls, and 0.70 W/m2 K in the floor.*Insulation means a reduction in loss of heat from an area that has been heated to a different temperature. If no heat has been applied, the insulation will be nominally the same as the outside temperature.
Please Note:

All sizes are approximate

External Width: 7.60m (24' 11")
External Depth: 3.30m (10' 9")
Internal Width: 7.36m (24' 1")
Internal Depth: 3.01m (9' 10")
Internal Area (m2): 22.17m2
Ridge Height: 2.49m (8' 2")
Internal Eaves (Front): 2.18m (7' 1")
Internal Eaves (Rear): 1.99m (6' 6")
Roof: Insulated IzoPanel
Roof Thickness: 135mm
Roof U-Value (W/m2k): 0.21
Overall Wall Thickness: 121mm
External Timber Thickness: 15mm Tongue and Groove
Framing: 70mm
Insulation Thickness: 25mm
Insulation Material:


Internal Finish:

10mm Plasterboard

Floor: 40mm Insulated Sandwich Panel
Floor Bearers: 35m (114' 9")
Door Style:

uPVC Patio Door

Door Material: Reinforced 5 Chamber uPVC Profile
Door Locking System:

Multi point locking system with 6 pin euro cylinder lock barrel

Door Walkthrough Height: 1.92m (6' 3")
Door Walkthrough Width: 1.82m (5' 11")
Window Locking System:

Multi Point with Mushroom Headed Espagnolettes

Glazing Material:

28mm Double Glazed, Toughened Glass


Pressure Treated

Approx. DIY Assembly Time: 4 - 5 Days*
*This is an approximate time only, based on 2 people. Assembly time may vary depending on season/weather conditions, foundation type, ability of those constructing, etc.
Please Note:

All fixings needed for assembly are supplied