Dunster House Ltd.
Incorporated. 1994
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What is a U-Value?

A U-Value is a measure of heat loss found within building materials used for walls, floors and roofs. U-Values are always measured in W/M2K (Watts per Metres2Kelvin). The higher the U-Value of a material is, the worse it performs in relation to retaining heat. So materials with a low U-Value have high levels of insulation.


Why should you insulate?

Good insulation will help protect you from paying large heating bills. For this reason, you should always look at the U-Value of the materials used within the construction of a garden building. As the majority of a building's heat is lost through the roof, walls and floor, insulating these areas is important.


Delivering quality, reliability and value with better insulation

We believe our excellent insulation provides you with a reliable garden building of superior quality at better value for money. Keeping your garden building insulated helps you to control its environment, which protects it from damage. This means you get a garden building which you can use all year round, that is built to last and one that represents a fantastic investment.


All round Insulation: walls

As a rule, timber isn't as good an insulator as materials like polyurethane, which are designed for insulation. For example, a log cabin with a 70mm wall has a U-Value of 1.41. But our best insulated walls, the 130mm TripleTherm™ walls, have a significantly lower U-Value of just 0.27. The reason for this is that we fill the cavity of these walls with 70mm thick foil-backed polyurethane insulation.



This first graph displays the U-Value of timber walls according to thickness. The blue bars in the graph display materials used within the construction of our garden buildings. Whereas the red bars display other materials that we don't use.


All round insulation: roof

Heat rises, so a poorly insulated roof will let out a lot of heat. Although U-Values for roofing are typically higher, the method of measurement is the same. Our Log Cabin roof insulation includes an 11mm MFP/25mm Polyurethane sandwich panels on top of our 19mm roof boards. This offers excellent roof insulation, compared to standard roof boards, and a U-value of 0.69.



All round insulation: floors

When it comes to insulating a building, the floor is all too often forgotten. Unlike some of our competitors, we don’t forget, and offer optional 25mm thick polyurethane insulation sheets for our Log Cabin floors to suspend below our 19mm or 28mm floor boards, which provides U-Values of 0.68 or 0.66. In comparison the typical 19mm timber floor board has a U-Value of 2.81. Our Garden Offices also feature insulated floors as standard with the lowest U-Value being just 0.38! 



Brickwork comparison graph

Some of you might be thinking "how does the U-Value in the timber used by Dunster House compare to the brickwork of my home?" Well, as you can see our TripleTherm log cabins and Garden Offices beat the insulation value of traditional Brick/Cavity/Breezeblock walls used in house construction. In fact, they even have a similar value to the brickwork found within more modern house construction, all at a fraction of the cost!



Typical House Construction - 102mm Brick Wall / 50mm Air Cavity / 100mm AAC Blocks / Mineral Wool / 12mm Plasterboard