Retaining Wall

This photo shows an ongoing issue for us i.e. what to do with the gap? How do we best connect the house with the backyard?
(On a tiny budget. Before even looking at the gap, we’ve already exceeded our retaining wall provisional cost item i.e. the cost of a good 2nd-hand small family vehicle, by the high-end price of a new small family vehicle – we’d like to stop well before we hit the grand saloon comparison stages!)

Below are the quotes and possible solutions.
(Apologies for some pretty bad pictures here)

1. Complete the wall with concrete sleepers, build a platform out with stairs leading down the side of the wall i.e.

Pros:

• Cheapest ($9k)
• Gets us to the backyard (which may be the future pool area)

Cons:

• No engineering cost factored in – would need to be certified under the existing certification for the wall – which may mean an additional cost
• Does not really connect the backyard – it would probably end up feeling like two separate properties.

2. Additional retaining wall bay and 2m wide concrete tiled stairs. Timber balustrade with stainless wire.

Pros:

• Should look very nice
• Will integrate the two areas without making it feel like two separate properties
• Waterproofed

Cons:

• Expensive (another new vehicle – $16k)
• No engineering cost factored in – would need to be certified under the existing certification for the wall – which may mean an additional cost

3. Additional 800mm retaining wall bay on each side. 2.5m wide coloured, concrete stairs (Boral range). Timber balustrade.

Pros:

• Should look nice
• Engineering cost is also included
• Will integrate the two areas without making it feel like two separate properties
• Award winning, home show advertising, landscape company

Cons:

• Reasonably expensive (student vehicle – $13k)
• Not rendered
• Not tiled
• No stainless wire in the balustrade, timber only
• No mention of waterproofing in quote
• No allowance for rock excavation in quote

4. Quick, with a hint of dodgy concrete, core filled blocks with timber external stairs on steel frame.

Pros:

• (Possibly) cheap ($4.3k for the core filled block retaining only – still sourcing a quote for the staircase)

Cons:

• Will possibly not look good
• Not rendered (yet)
• Tricky dead space under staircase – we would actually prefer this being covered with concrete block work.
• Timber stairs on steel frame may not be a good solution – can possibly get concrete formed stairs instead, but cost could end up being the same as the above two quotes?
• No mention of waterproofing in quote

5. Complete the wall and forget about the extra 250-300sqm backyard…for now (~$5k)

6. Build a 1.8m high raised pool bang in the middle, use the pool walls to retain the 4.1m gap. Step down to rest of backyard down both/either side(s) of 8m long pool. (Unknown cost)

The saga continues…

On the upside, we absolutely love the roof line from the back of the property!