it all depends on where the garage is situated. if the garage is attatched to the house then building regs will come into force. if it is detatched then it is still really a garage you use as a playroom. Integral garages will nearly always have fire barriers because of the garage element. in this respect not too much to worry about on that front. The only other things are if you have altered any structual or loadbearing walls are moved/added any extra sockets, services etc a private building inspector is usually better than a council employed local authority as these guys are usualyy retired or ex council building inspectors who use a bit of common sense. costing wise expect to pay upto £450 for the inspection and certificate plus anything else picked up on. If an experienced builder as done this for you then all should be ok. Bear in mind that not all garage conversions need to go through building regs it depends on each individual case. If someone else near to yoa as converted you would be better to ask what they had to do if any. if you are still unsure then ask at the planning office(building control) but like others have said if regs are required then the house will not be able to be sold with playroom it would have to be sold with either (garage) or (storage room)
hope this helps

Yes you should have had building regs if used as a habitable room.

Hi, there are two different areas you will need to look at - Planning Permission and Building Regulations. They are completely different. For planning permission you will need to find out if the Permitted Development rights for garage conversions are still intact on your property by calling your local authority planning office. If the right to convert isn't there, you will need to apply for planning permission but there will be no fee for this application. Planning permission can be enforced on by an Authority. There is also an option called a Lawful Development Certificate you can get to prove it didn't need planning permission if PD rights are intact (but this will cost £150 as the works have already been done)
Building Regulations can't be enforced on until it becomes deemed as a dangerous structure. You can get a regularisation certificate from your LA Building Control or a company that is registered to self-certify (this is an area that you don't have to go to your Council for) but this may be expensive. Once you ask someone to do this then you will have to bring the conversion up to standard if it isn't already. When and if you plan on selling your property, solicitors/insurers are keen on building regs certificates and especially a document in respect of planning permission.

Regards

Paul

if its now used as a habitable room yes,you will also have problems with this when it comes to resell ,as surveyors report will highlight this,also if you carried this out without building regs they will think you have done more without them,i would pay building control to come and inspect ,and rectify if any defects ,that way you can still get building cert

The answer is yes, building control can force you to bring the conversion, up to building regulations.
You should also note that the playroom would void your house insurance as it does not meet building regulations, you would not also be able to sell your property with the conversion classed as a playroom, it would still be classed as a garage. Hope this helps

yes and also make you put it back to how it was

Yes and you will most probably have to put it back the way it originally was