Finishing garage wall

[Lincolnshire Ian]

We need to finish our timber-framed, attached to the house, garage. 

The walls are 140mm studs with 120mm insulation which was fitted by mistake in the TF factory. 

We have considered plasterboard, plastering and paint, but this is quite an expensive way to finish the garage. Then we have OSB board, cheap to buy and easy to install, but with a utilitarian appearance. 

Are there any other options we should consider - we want it to look nice for the least possible money (who doesn't). 

Here is a picture of the wall. 

Thanks 

[crispy_wafer]

OSB + PB, or just Fermcell, skim it and swallow the cost.  Make it a nice space to use and work in, and give the walls the ability to hold tools/bike racks/ladder hangers.

[Nick Laslett]

I’m sure you are already on top of this, but my understanding is there are specific fire regs that dictate how you finish an attached garage. But I could be mistaken. So PB with 30 min fire rating is possibly required. 

Edited November 4 by Nick Laslett

[Russell griffiths]

Our attached garage is lined with 18mm osb, then pink fire board and skimmed. 
pits made a lovely room and I’m happy it’s sort of safe. 

[Eric]

Your approved drawings will state what is required for fire regs, for other walls as above just plasterboard or osb/ply then plasterboard means there is always material behind the plasterboard for fixing items in the future.

[Lincolnshire Ian]

Thanks for your response everyone, very helpful. 

Its seems pretty obvious now it's been highlighted that I should use fire resistant plasterboard. 

I have checked my BC drawings + the build specification from the TF company and it's not mentioned. 

Thanks Build Hub and the super community for keeping me right.