When researching different Garden Studies/Offices/Studios/Rooms/Pods/ Shoffices (shed + office apparently), it's difficult to understand the quality of each one. One of the major variances is insulation. Building regulations aside, if it's somewhere you're going to spend 8 hours a day, 5 days a week (or more), insulation is not something you'll want to compromise on.
How do I know how well insulated it is?
There are many different types and thicknesses of insulation, all of which have different thermal properties. The way to establish how well-insulated a Garden Room is is to check the U-Value of each element (wall, floor, roof, window and door). Unfortunately, for me, a bullet point saying "fully insulated" doesn't quite cut it.
What is a U-Value?
The U-Value of an element (wall, floor, roof, window or door) is the rate of heat loss through that element. The lower the U-Value, the slower the rate of heat loss i.e. the better insulated it is. By increasing the thickness or quality of insulation, you lower the U-Value.
Why does this matter?
Lets look at 2 example constructions:
Construction A
90mm thick timber stud wall with mineral wool insulation between the studs. There are various qualities of insulation but, taking an average spec, this gives a U-Value of say 0.3W/m2K.
That means that the heat loss through a 6m2 wall is 1.8W/K (Don't worry about what this means in technical terms, just look at it from a comparison point of view.)
Construction B
A 140mm thick timber kit with 140mm rigid insulation between the studs with an insulated external breather membrane and an insulated internal vapour control layer which gives a U-Value of 0.17W/m2K.
The equivalent heat loss through a 6m2 wall is 1.02W/K.
This means that there is 45% less heat loss through Construction B compared with Construction A.
The variance in specification can have a significant impact on the performance and fit-for-purpose...ness of your home office.
A Benchmark for Comparison
If you were considering an extension to your home to accommodate your new office, generally, your extension would need to meet the following U-Values:
- Wall - 0.22W/m2K
- Floor - 0.18W/m2K
- Flat roof - 0.18W/m2K
- Pitched roof - 0.15W/m2K
- Windows and Doors - 1.6W/m2K
Business doesn’t stop during the winter. If I intend to spend 8 hours a day 5-days a week in my Garden Office, I’d prefer it to be more than just a "fully insulated" garden shed.
This gives you a benchmark when looking at possible Garden Rooms to establish how well-insulated it is in comparison to your house.
This is a very broad brush introduction to U-Values. Please feel free to get in touch if you have any queries about a particular specification you want to explore.