I would go for 500mm to foundation base from low side and make the base about 750mm wide x 300mm deep. Youll need to start the brick wall at 330mm wide at the base then about 1/2 way up the wall step it into a 215mm wide wall.
Is the retaining wall near any other structures, roads etc?
If you need to find a tradesperson to get your job done, please try our local search below,
or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Please select a service and enter a location to continue...
Are you a trade or supplier? You can create your listing free at DIYnot Local