Previous owner of my new place built up a room above the car-porch roof area. From what I read from various sites and guides this should be open to sky and not closed up. 

I'm wondering what should I do? I do notice that majority of the estate all have similar situation and wondering whether I can write in to leave it as is? Any one has such experiences before to share or advise? 

Thank you

write in to URA and seek their advise is the best. Cos there are some housing estates where this enclosed room is actually allowed. So if you see most of the houses around your estate have this additional room, then high chance is that it is actually legal.

In the even that URA informs you that the room does not conform to regulation, then you would likely need to remove the roof and walls forming the room.

Thanks Snoozee. hopefully it's allowed esp since majority of estate of renovated houses all have it!

I'm planning to enlarged attic floor that falls within the envelop space. My 1st 2 floors are 7m high so looks like I will be able to build a larger attic floor within the envelope area on top. Only worry is this covered porch is illegal which then the added attic extension may be deemed to "increase the building bulk" (as per the envelop guidelines"

Keeping fingers crossed

While the covered carporch roof might be legal, you trying to extend the attic until above the carporch roof may not be since it will be outside the envelope already. Unless you leave the roof above the carporch roof room as an open terrace which might be still passable though you will need to install high lightning conductors for safety. 
best is check with URA to get clarifications as only they can tell you whether your plans can or cannot be done

good point. Yup only extending the attic only within the envelope and will not be above the car porch, only above the main house area. OK will definitely check with URA, don't want to have this uncertainty hanging over while trying to get the reno done.

ID I spoke to also warned that there may be a 6 months wait for URA/BCA approval for doing the attic up. Hopefully it's faster than that!

hope your ID is well versed in landed house regulations.

whether you can get approvals within 6 months or not depends on how many times your submitted plans get rejected. URA takes about 1 month to check and approve/reject. So if your submission gets rejected, the same process and wait time is repeated. Usually BCA submission is done after URA approves of the plans. BCA side wait time is shorter (last time standard is 7 working days) but of cos if reject then repeat same process. One thing you can "help" is to pay up promptly as soon as you are requested to pay for the submissions. Cos the authorities will only start processing upon payment. So if you take you time to pay then they will also take their time to start processing.