[Advice Needed] Laying of Garden Slabs

[ProblematicPanda15]

Hi All,

 

We are putting in new garden slabs as part of full home renovation. As we are putting bifold doors at the back of the house, we wanted to raise the level of the patio outside of the bifolds so that they are level with the bottom of the bifolds and that there is not a big step down to the outside. 

 

Rather than taking out the existing patio paving, my builder is looking to build onto of the existing patio (hardcore, mortar and then slabs).

 

Is this ok to do? I suppose there aren't any issues in doing it this way, but it sounded like my builder want to take the easy way of doing it instead of doing or properly by removing everything first, and building up again from there? 

 

Any advice would be greatly appreciated!

 

Thank you.