I am looking into getting a home garden room for an office. One thing I am worried about is the heating cost. They all come with 2KW or 3KW heaters but if you need that on all day, it's going to cost a lot. So trying to find out more about insulation options. Some do 100ml rockwool, others sip panels. But I guess you only really know when you have the thing. Has anyone any advice on a garden room you may have got recenly and how the insulation and subsequent heating went, thanks
Cellulose insulation is a good option for heat retention. Good glazing is also a must. Where are you based?
I have a DIY garden room with 80mm (wall) and 100mm (roof) external woodfibre insulation, with DIY triple glazed window and French doors and reasonable amounts of permanently open ventilation (gaps around the doors!).
It is used daily as my office and at weekends for hanging out.
In the last 30 days it has averaged 5kWh/day electricity consumption on the 2kW resistive heater.
In practice this means around an hour at full blast and then trickling for the rest of the day.
If I wanted more economy I would add internal insulation, close up the gaps and use a single room heat pump/HRV instead of a resistive heater.
Glazing will make a big difference. If you have a window that gets direct sun (I don't) then the room will stay warm during the day without heating, just needing a boost in the morning. Obvs that may cause overheating in summer so consider shading. The risk of overheating from a poorly insulated roof is greater.
So in your position I would max out the insulation spec as that's awkward to increase later, fit closeable ventilation, and think about solar gain and shading.
Remember that a small building has a massive surface area. Mine has maybe 25% the surface area of the house even though it's only 7% the floor area.
North County Dublin.
One company was wall: 70mm log wall, 100 mm rock wool. Ceiling: 100 mm rock wool, Floor 40mm Kingsoan
Is there a company you'd recommend that does garden rooms and is really good at insulating them?
@Tim Robbins hey I'm looking at doing the same as your self. Did you ever get a lead on a decent company doing these?
I figure worst comes to worst, go for which ever one seems like the best and buy a bunch of kingspan insualtion boards to glue on the inside. Or at least that's my current fail safe plan.