Building a lofted garage - some questions please

Manuel

Hi,
I have planning approved for a lofted garage, 40ft by 20ft, away from the house.

I'd like to get some advice please regarding heating/insulation.

The downstairs is solely for storage - garden equipment, bikes, fuel, etc.
Our plan for the upstairs is for a playroom for the kids and an office for ourselves.

So I need heat/insulation for the loft only. How feasible is this? Can I insulate/heat the loft adequately without insulating the garage beneath?

Can it be done with a cavity block construction, or would I need to build cavity walls? If - God forbid - myself and herself ever needed to move out to live in the "garage" so one of the kids could have the house, I guess I would need to plan for that possibility now, and again, would that mean that a cavity wall construction would be imperative?

I see lots of lofted garages around the place, so I guess others have had to consider these things ....

Any advice appreciated. Thanks.

BryanF

Manuel wrote: »

So I need heat/insulation for the loft only. How feasible is this? Can I insulate/heat the loft adequately without insulating the garage beneath?

give your comment further on re further proofing, ask yourself how you can easily retro-fit at a later date. I would say its better to just do the whole lot now.

Manuel wrote: »

Can it be done with a cavity block construction, or would I need to build cavity walls? ... would that mean that a cavity wall construction would be imperative?

you have lots of options
block on flat, wide cavity, timber frame, ICF, strawbale, etc. If you go cavity block then your talking about external insulation, if you go cavity wall your talking about pumping or placing insulation as you go.
which every you go for, get the details, specification/drawings right and if your not in the trades get a professional to inspect and ensure works are done to a high standard and at the very minimum the current required Building regulations

Manuel wrote: »

I see lots of lofted garages around the place, so I guess others have had to consider these things .....

seriously consider high levels of insulation and air-tightness, especially if your working from there through the winter. if this is the case don't bother asking anyone who is not spending extended amounts of time in there 'office' sitting at a desk.

PS if you have received planning for an office above garage does this mean you need a BER ?

Manuel

Hi Bryan,
Thanks for that.
No, the planning doesn't include an "office" as such. I'm just thinking of somewhere quiet I can go to sit for an hour or so in peace. It would need to be warm though! It's not intended as a commercial office.

But you raise another important issue. If this should in time become a residence (out of necessity, say), are there safety concerns if it was constructed as a garage? Pardon my ignorance, but for example is there a radon barrier in the foundation of a garage, as for a house, etc?

I do intend to employ a professional, I'm just bouncing ideas at the moment. I'm just a bit nervous about skimping on insulation for example in the short term, in case I find years down the line that I need the whole garage to be habitable. That's not a plan at the moment, just a contingency the way the country is going .....

Thanks again.

BryanF

Manuel wrote: »

Hi Bryan,
Thanks for that.
No, the planning doesn't include an "office" as such. I'm just thinking of somewhere quiet I can go to sit for an hour or so in peace. It would need to be warm though! It's not intended as a commercial office.

But you raise another important issue. If this should in time become a residence (out of necessity, say), are there safety concerns if it was constructed as a garage? Pardon my ignorance, but for example is there a radon barrier in the foundation of a garage, as for a house, etc?

I do intend to employ a professional, I'm just bouncing ideas at the moment. I'm just a bit nervous about skimping on insulation for example in the short term, in case I find years down the line that I need the whole garage to be habitable. That's not a plan at the moment, just a contingency the way the country is going .....

Thanks again.

Manuel,
threat the structure as if it were a house, put in a sump and radon barrier, in the scheme of things there not expensive, you are building the mother of all garages:) if this loft is usable to the external walls, thats circa 160msq of garage/office/kidsroom of space. my terraced two bed house is smaller than your proposed first floor:D

I'd recommend you go to an Arch tech with experience in low energy buildings, with an eye to how you can build with ease of future proofing in mind. Id also be specifically be looking at orientation and how you can gain the maximum 'free' heat from the sun by placing large windows in the south elevation and minimising openings on the north

*just a caveat that conversion and planning for changing a garage to house is not always plain sailing, especially if the planners believe that was you intention from the outset (I'm not suggesting this is your motive)

galwaytt

I have 2 garages, one a lofted garage -12m x 8m. If you do not insulate the GF, you are wasting your time and money - as the garage below will act as a fridge under the loft above. Build the whole thing one common method, incl insulation, and whether of TF/blocks etc is up to yourself.

Mine is insulated out the wazoo, including the roof, and needs no heating at all. Indeed, park a car with a warm engine in it, and it takes hours and hours for it to cool down, during which time............the garage gets 'free' heat as well !! Win-Win ! It also means that long-term, stuff left in it doesn't rust.......which is what happens in cold garages.

Slig

This really is a can of worms isue, Technically a garage may be built along with a residence exempt from planning permission (under strict conditions). Anything bigger than 25sqM floor area (which is realistically what you are talking about) will need planning and will be subject to inspection by the planning authority. This becomes an issue because they dont like people creating living space in garages. It is almost always done to a standard far below building and planning regs, rented out as a seperate dwelling or used for unregulated commercial purposes.

However, another issue is that these things always grow, what starts with a small storage space in the attic of the planning approved car garage quickly gets insulation added, and a toilet & shower, and then a little extra head room in the attic space, and a few extra foot added to the end, and a few more windows.................

By the time you have your ideal garage finally finished you get a letter from the enforcement section of the local authority requiring you to apply for retention permission or enivetably demolish the whole thing or substantial sections of it.

galwaytt

Slig wrote: »

This really is a can of worms isue, Technically a garage may be built along with a residence exempt from planning permission (under strict conditions). Anything bigger than 25sqM floor area (which is realistically what you are talking about) will need planning and will be subject to inspection by the planning authority. This becomes an issue because they dont like people creating living space in garages. It is almost always done to a standard far below building and planning regs, rented out as a seperate dwelling or used for unregulated commercial purposes.

However, another issue is that these things always grow, what starts with a small storage space in the attic of the planning approved car garage quickly gets insulation added, and a toilet & shower, and then a little extra head room in the attic space, and a few extra foot added to the end, and a few more windows.................

By the time you have your ideal garage finally finished you get a letter from the enforcement section of the local authority requiring you to apply for retention permission or enivetably demolish the whole thing or substantial sections of it.

I think you need to re-read OP's post.....he HAS planning for it.

OP has already stated he has PP for his 40 x 20ft garage.

What he builds it out of, and the standard to which he builds it, is entirely up to him. If he wants to build it to 'passive' or other hight standard etc, he's entitled to do so, and the planner's have no say in it.

High standard building does not make it a dwelling.

Slig

ya sorry about that, dont know how I missed little bit of information:rolleyes:


You are perfectly correct about the standard of build, the LA has no say in how its built but remember that it has only planning permission as a garage not a dwelling. My latter (more relevant) points still stand though.

Manuel

Thanks for the feedback. OK, so it looks like I'll go with:

- Cavity wall construction
- Foundation with radon barrier and sump and insulated floor
- Maybe 2 inch rigid board in the cavity while it's going up, or maybe hold out for the option of pump fill some time in the distant future if ever needed
- insulate the bejayses out of the loft , floor, walls and roof.

I haven't looked at insulated garage doors, just a bit of browsing on the web, but are they in general any good? Are they very expensive? If I am going to insulate the cavity from the start I guess I should consider insulating the garage door to some extent, within reason.

Thanks again for any help. I couldn't find much on insulating garages, lofted or otherwise, on this forum, but if this has all been covered somewhere else please let me know.

BryanF

Manuel wrote: »

Thanks for the feedback. OK, so it looks like I'll go with:

- Cavity wall construction
- Foundation with radon barrier and sump and insulated floor
- Maybe 2 inch rigid board in the cavity while it's going up, or maybe hold out for the option of pump fill some time in the distant future if ever needed
- insulate the bejayses out of the loft , floor, walls and roof.

I haven't looked at insulated garage doors, just a bit of browsing on the web, but are they in general any good? Are they very expensive? If I am going to insulate the cavity from the start I guess I should consider insulating the garage door to some extent, within reason.

Thanks again for any help. I couldn't find much on insulating garages, lofted or otherwise, on this forum, but if this has all been covered somewhere else please let me know.

Manuel,
you need to read http://www.environ.ie/en/TGD/#Part%20L%20Supplementary%20Documents and basically all the documents on this page, understand them and ensure they are incorporated into your build OTHERWISE hire an Arch tech to do it for you and supervise the construction.
things have moved beyond 2inchs of insulation in walls, the cavity now need to be widened to 150mm or wider. regarding insulation your floor wall and ceiling, that's great, but you now need to be thinking about removing the thermal bridges where these elements meet + air-tightness of the entire building envelope. re garage door: there might be a cheaper way of doing this yourself with the help of wood-fibre type insulation boards fixed to the back of the door, but stopping the drafts is going to be the challenge.
dont forget with all the above regulations that retaining the correct amount of natural ventilation is essential especially if you may have car fumes in the garage.

galwaytt

Manuel wrote: »

Thanks for the feedback. OK, so it looks like I'll go with:

- Cavity wall construction
- Foundation with radon barrier and sump and insulated floor
- Maybe 2 inch rigid board in the cavity while it's going up, or maybe hold out for the option of pump fill some time in the distant future if ever needed
- insulate the bejayses out of the loft , floor, walls and roof.

I haven't looked at insulated garage doors, just a bit of browsing on the web, but are they in general any good? Are they very expensive? If I am going to insulate the cavity from the start I guess I should consider insulating the garage door to some extent, within reason.

Thanks again for any help. I couldn't find much on insulating garages, lofted or otherwise, on this forum, but if this has all been covered somewhere else please let me know.

If you must use block construction, 50mm insulation is 15 years out of date. Better leave it and pump it, just before it's plastered. For a garage, 100mm cavity is fine.

Insulated doors ? Well, in recent years I've had cause to buy 5 - all insulated, sectional, and I wouldn't use anything else. They are very good. Not cheap, but you only buy them once - the cheaper ones will need replacing eventually.
If you build a good garage, fit a good door.

I find mine windtight, even in driving rain, and have never had to fix or adjust them, some now 10yrs old, and they work as-new, so works for me