Hi, it would be great if you could upload a photo of the garden and then I would be able to suggest a suitable position for the decking

The garden was basically sloped and I needed to build a retaining wall at the bottom of the garden and raise the corner 4ft so we could then push out the lawn and make more of the garden aspect

I think I’d advise against decking too, at least in the area close to the house as it would need to below the level of the damp course which would involve taking up the paving and a lot of ground works anyway. Decking needs to be raised so there’s no contact with ground but by doing so can create other problems such as make a great nesting site for rats and other rodents, not to mention slipperyness and more maintenance. Not saying it can’t be done and being a party pooper🙂, you could have steel frame and composite decking, just think it will be more work than you’re envisioning. With regards drainage and moss I’m guessing its north facing and doesn’t get much sun? Does water pool or puddle on the paving? Perhaps a drainage channel (see example pic) next to house may work more effectively but in a small area I don’t think it‘d be necessary. Certainly check the gutters for moss but i wouldn’t worry too much about the roof unless it’s really bad. On our house the birds tend to flick moss off the roof and gutters in search of food. You can get porcelain paving that looks like wood, maybe this could be an alternative. Personally I would get some advice from a few local landscapers to see what is possible and look at drainage.

https://docs.google.com/forms/d/e/1FAIpQLSci_byC162hJI-iq6kb82Dx-ZZ9XnWsFpz74vASpWBLL04hrg/viewform?usp=sf_link I would appreciate if anyone who does gardening would fill out this short survey to help with my A level product design project which is based on helping to prevent back pain whilst gardening.