Replacement garden gate width

[Adam]

I need to replace my garden gate as it's falling to bits. It seems the standard width of a garden gate is 900mm, however mine appears to be 890mm. Attached to the side of the house is a piece of 4x2" wood running vertically and the hinges are attached to a post separating my house with the neighbours next door.

The garden gate is 900m wide which is exactly the width of the space between both posts. It doesn't leave me any room nor does it allow for the wood expanding etc.

This is the gate I'm looking at: http://www.wickes.co.uk/Wickes-Pressure-Treated-Curved-Top-Gate-1800-x-900mm/p/137212

Obviously I'm not going to starting hacking the gate to bits so are there any tips to allow me to install this standard size gate?

 

[Adam]

Take the existing bit of wood off and attach a thinner bit?

This did seem the best solution but I'm sure when I got a quote for fencing and asked them to do the gate at the same time they said it's best not to disturb that post attached to the brick. If I could avoid it then I would prefer to but I can't see that I have many options!