single skin breeze block garden room + insulation

butterpie

Hi all,
Does anybody know if a single skin breeze block garden room, with peirs, insulated with something like 120 mm Kingspan and maybe external insulation boards would be warm enough to use as an office?

I've spoken to a building control surveyor at the local council and he says it does not have to be double skin with a cavity as it is not classed as a habitable room.

I thought single skin would take up less floor space, require shallower foundations, and also be a bit cheaper and quicker to build.

On the other hand if its too cold to type or draw properly and I need heaters on full blast then it's a false economy

any advice kindly appreciated
bp

Doozergirl

Solid insulation is more efficient than rockwool. 120mm of kingspan would be warm, yes.

What would concern me is the possibility of damp. It will need to be drylined with foil backed boards. Don't skimp on the quality of the plasterer you use.

System

I would be looking at timber frame for this...

warmhands.coldheart

the_r_sole wrote: »

I would be looking at timber frame for this...

A good Quality custom made garden shed, insulated inside should do the job and would be cheaper than building something... I had a shed built years ago at a previous house I lived in, When I approached the company they pointed out they don't make sheds, they make portable buildings, and boy they were right. TOP JOB and you could have lived in the thing..

jamesmorgan

warmhands.coldheart wrote: »

A good Quality custom made garden shed, insulated inside should do the job and would be cheaper than building something... I had a shed built years ago at a previous house I lived in, When I approached the company they pointed out they don't make sheds, they make portable buildings, and boy they were right. TOP JOB and you could have lived in the thing..

I would also echo this. I have a timber based garden office which is fully insulated, and is fine to use any time of the year (even to sleep in if required). However, this type of construction won't come cheap. Expect to budget £800-£1400/m2 - http://www.thegardenroomguide.co.uk/garden-office-guide-pricing/2011/09/12/. This is possibly marginally cheaper than traditional building approaches. If the cost of your construction is coming out a lot cheaper, you need to understand why - it is possible that you are making too many compromises.

It is interesting that most of the new build properties near us are also using a timber based approach rather than breezeblock/bricks. Not sure whether this is for cost reasons or other (eg timescales, energy efficiency).

cyclonebri1

There will be no saving on foundation cost between a single and double block 1 storey build, they still need to be substantial and deep enough to to withstand earth conditions and freezing.

There are actually no building reg requirements for a garden building such as this, it simply has to be safely constructed, ie, not be a risk to yourself or others.

You can't get away from the fact that it will need heating, there will be no thermal input form any thing or anybody else.

And yes if you try to keep it warm by closing down ventilation then condensation may be an issue.

The other thing is most of the heat will disappear up through the roof, this is where you should concentrate your efforts regardless of single or double skin.

warmhands.coldheart

Good thing about a "Portable Building" (I'll not call them a shed) is they can be insulated all round (roof, walls and floor) pretty easily... meaning more energy efficient from a heating point of view

cyclonebri1

warmhands.coldheart wrote: »

Good thing about a "Portable Building" (I'll not call them a shed) is they can be insulated all round (roof, walls and floor) pretty easily... meaning more energy efficient from a heating point of view

You need to re-check that against the insulation charts that are available, it's more easily done with a solid/brick/block built unit.


No one has mentioned the re-sale value yet, mse remember, a solid construction will add value, a "shed" will be valued simply as a shed, ie, something in the garden.

System

tbh my suggestion wasn't really for a shed, I meant a proper timber frame construction, properly insulated and not designed to be portable… could even do block/brick for an outer leaf if you wanted more substantial… although initial thoughts were to have lighter founds/slab etc and save a bit there over traditional construction.

butterpie

Thanks for feedback everyone. Thinking about it, a single skin block building still needs piers so I wouldn't be saving much floor space over double skin. If a good quality block building is not much more expensive than a good quality timber framed one, then I may opt for the block

cyclonebri1

the_r_sole wrote: »

tbh my suggestion wasn't really for a shed, I meant a proper timber frame construction, properly insulated and not designed to be portable… could even do block/brick for an outer leaf if you wanted more substantial… although initial thoughts were to have lighter founds/slab etc and save a bit there over traditional construction.

I understand that, but it's just peoples perception of a wooden garden building compared to a masonry 1.


I'm talking off the top of my head here and I realise the thread is about done but there may even be insurance implications here, ie, again if valuables are left in there it may be perceived to be more secure is solid built.


Yes you or I could make either equally secure, but..................