Bob Smith wrote:
I am considering building a home office in the garden (kind of elaborate
shed). Size would need to be around 6ft x 10ft.

I am thinking of starting with a regular commercial shed, and doing a DIY
conversion.

Has anyone done this? I need to add the maximum insulation to help keep it
warm/reduce heating costs/keep cooler in summer, and add a double glazed
window, and extenal door.

I haven't done it myself, but have sen it done several times.

Your approach is corect in teh essentials. Don't forget floor insulation.


What is the best way to add insulation, and what thickness is required to
meet the highest insulation standards. I want to end up with a
white/magnolia flat finish on the walls, and a laminate floor.


Mmm. You should be able to wedge about 50mm of celotex between the
structural bits, and plate over with foil backed plasterboard. Paper or
skim or both and paint.

Floor is a bot more of an issue. Ether replace it completely with an
insulated tupe or put studowrk across it,celotex insulate, chip out and
laminate it.

What would be cheapest way to heat the "office". Some heat will be gained by
the computer/lighting etc. Would it be better to use underfloor heating
under the laminate, or a aircon unit (as a heat pump), or something else?


To be honest, the computer/lighting stuff should be enough. Backed up
with an electric heater for really cold days.

UFH means really designing a custom floor from scratch and unless wet is
no saving at all. Aircon isn't bad..but its an expensive install.

You have to balance installation costs (a couple of quid for an electric
heater versus thousands for aircon or UFH) - against running costs over
the units lifetime. A couple of grand buys a lot of electricity.

A small shed well insulated should only need 200-500W to be cosy. The
lower end of that is about what all the installed gear+ human will
generate like as not. That leaves 300W to find.