Secure lock for 35mm internal oak door

[swebb99]

Hi I have a xljoinery internal oak door fitted in my garage between it and an side extension. Ideally I would like to have a 5 level sash lock in the door for an extra bit of security but I'm really not sure it one would fit. A typical 5 level lock requires a hole of 16-15mm width and a face plate of 25mm so with the door only being 35mm wide I'm not sure if this means too much wood is being cut out.

Thoughts ?

 

[23vc]

I've fitted mortice locks that size to those doors, you've just gotta be very careful not to either break out the side as you're drilling it out, and go carefully rebating the face with only a few mm each side. Not really sure of the overall strength either seeing as it's veneered . But it's doable