Costly Retaining Wall and Fence Mistakes You Can Easily Avoid

Retaining wall and fence planning should happen together, even if different contractors build each structure months apart. The wall changes the ground levels. The fence affects privacy, access and how the finished space feels. Underground, both structures also need room for posts, footings and drainage.

When nobody considers those details together, small decisions can create frustrating and expensive problems later.

We see this regularly on new homes and developments around Brisbane and South East Queensland. Retaining walls may go in before individual blocks are released. After that, the builder cuts the site, establishes the house level and completes the home. Eventually, the fencing contractor arrives and has to make the fence work with decisions made months earlier.

That is often where the problems become obvious.

At Conker, we prefer to start with a different question.

What does the finished property actually need to do?

Once you understand that, the retaining wall and fence become parts of the solution rather than separate jobs competing for space.

A Real Retaining Wall and Fence Planning Headache

One project sticks in my mind because it shows how a few hundred millimetres can completely change the result.

The finished house level ended up about 300 millimetres higher than expected. Meanwhile, the existing retaining wall sat a few hundred millimetres lower than where we really needed it.

Neither issue seemed enormous on its own.

Together, they created a serious privacy problem.

If we had simply installed a standard 1.8 metre fence on the designated wall, the fence would have effectively finished around waist height when viewed from the elevated house side.

On paper, the property would still have had a 1.8 metre fence.

From the homeowner’s living area, however, it would have felt far too low.

By then, the house already stood at its finished level and the retaining wall already existed. Moving either structure made little sense.

So we had to get creative.

We introduced a plinth along the bottom and added a screen topper above the fence. Those two adjustments brought the overall height to a level that suited the finished property.

The solution worked well.

However, the real lesson came from understanding why we needed that solution at all.

Had someone considered the house level, retaining wall and future fence together from the beginning, there would have been far more options before construction locked everything into place.

A few hundred millimetres can look insignificant on a drawing.

Once you stand in the finished backyard, those same few hundred millimetres can completely change privacy, proportions and how the space feels.

Why Retaining Wall and Fence Planning Matters

Residential construction often divides a property into individual scopes of work.

The retaining contractor builds the wall.

Later, a fencing contractor installs the fence.

Another team pours the driveway or pathway.

Then the landscaper finishes the gardens.

Every contractor might complete their own work properly, yet the finished property can still feel awkward.

The problem often sits between the individual jobs.

A retaining wall establishes new levels. Those levels influence how high the fence feels. Fence posts need room underground, while retaining wall posts already occupy some of that space. Drainage gravel and pipework may sit behind the sleepers. Gates, paths and driveways introduce another set of heights and connections.

Everything influences something else.

At Conker, that is why we look beyond the structure someone initially asks us to quote.

Homeowners do not live with four separate construction projects.

They live with one property.

Good retaining wall and fence planning should reflect that.

Sometimes You Need to Question the Wall Itself

When a homeowner says, “I need a retaining wall here,” I do not immediately start thinking about sleepers, posts and wall heights.

First, I want to understand what the wall actually achieves.

Are we trying to create more usable lawn?

Does the homeowner need privacy?

Will the wall support a driveway or outdoor area?

Is there a future pool to consider?

Where will people walk?

Does a gate need to connect through this section?

What will happen with the gardens?

Where does water travel during heavy rain?

Could changing the levels in another way achieve a better result?

People sometimes approach retaining walls with a very fixed mindset.

There is a change in level, therefore there must be a wall.

That is not always true.

Sometimes the property genuinely needs substantial retaining. In other situations, a smaller wall can achieve the same outcome. Occasionally, I look at the site and question whether the proposed wall needs to exist at all.

Retaining is not cheap, and there is far more involved than simply putting a few posts in the ground.

Excavation, access, footings, drainage, soil removal, surrounding structures and finished levels all affect the job.

At Conker, we prefer to work out the real outcome first and then work backwards.

We apply the same thinking to concrete.

More is not automatically better.

The right amount, in the right place, for the right reason usually creates the better property.

Look Beyond the Wall Before You Build It

When I arrive at a property, I am rarely looking at only the structure directly in front of me.

I am looking at how people will use the entire space.

Where do you naturally walk from the garage to the backyard?

Could a future gate make that movement easier?

Which part of the yard needs privacy from the neighbours?

Will the kids use this area?

Could a pool change the layout later?

Does a driveway sit close to the retaining wall?

Where will garden beds eventually go?

What view will you have from inside the house?

Most importantly in South East Queensland, where will water travel when we get one of our heavy summer storms?

These questions may sound unrelated to a retaining wall.

They are not.

The answers influence where the wall should sit, how high it should be and whether another layout could work better.

For example, moving a wall slightly may leave enough room for a useful path. Changing the finished level could improve privacy. Adjusting where the wall ends might create a cleaner location for a future gate.

Early planning keeps those options open.

Once concrete footings and steel posts go into the ground, the site becomes much less forgiving.

Build the Wall First, But Think About the Fence First

On many projects, the retaining wall should physically go in before the fence.

That sequence makes sense because the wall establishes the ground levels that everything else needs to follow.

However, construction order and planning order are not the same thing.

Before excavation begins, think about where the fence will run.

Consider how high the combined wall and fence will feel from each side.

Check likely fence post positions.

Look at how the fence may need to step as the ground level changes.

Think about gates and access points.

Consider what happens where the retaining wall finishes.

Most of these decisions cost very little while the project still exists as measurements and marks on a plan.

After the contractor pours footings, installs posts and completes the wall, changing those same decisions can become expensive.

Moving a line on a drawing takes seconds.

Moving a completed retaining wall does not.

Good Retaining Wall and Fence Planning Starts Underground

The sleepers are the most visible part of a concrete retaining wall, but much of the important work happens below or behind them.

Structural posts extend into concrete footings. Drainage gravel occupies space behind the wall. An agricultural pipe may run along the back to collect water, while filter fabric helps keep soil out of the drainage zone.

Then the fencing contractor arrives.

They need another row of holes.

This is where small planning gaps can create headaches.

One fence post might land beside a retaining wall post. Another footing may need to occupy the drainage zone. Digging in the wrong location could damage the agricultural pipe behind the wall.

Shift one post and the spacing of several fence panels may change.

Suddenly, everyone starts trying to solve a problem onsite that could have been identified much earlier.

At Conker, we want to spot those conflicts before somebody puts an auger into the ground.

The retaining wall can work perfectly on its own.

Likewise, the fence can perform perfectly on its own.

Problems begin when both structures need the same piece of ground.

A Simple Drainage Detail That Made a Big Difference

One retaining wall project gave us a useful reminder that the best solutions are not always complicated.

The area received a significant amount of overland water during heavy rain.

The obvious approach might have been to close the area across the top of the retaining wall completely.

Instead, I chose to leave a controlled route for the water.

We created an approximately 300 millimetre decorative band across the top of the wall.

Visually, it became part of the landscaping.

Functionally, it did something much more important.

Surface water could move through the decorative zone and directly into the drainage gravel behind the retaining wall. From there, the system directed it towards the agricultural pipe and stormwater line.

It was a simple change.

However, it suited the way water actually moved across the property.

That matters in Brisbane and across South East Queensland because storms can drop a large amount of water in a short period.

Trying to block every possible path rarely solves the bigger issue.

At Conker, we would rather understand where the water wants to travel and give it a safe route.

Good drainage often comes down to directing water, not fighting it.

Water Does Not Care Who Built What

This principle applies to almost every outdoor construction project.

Water does not know where the retaining contractor’s responsibility ended.

It does not care who installed the fence.

Nor does it recognise where the landscaper’s scope began.

Gravity controls the outcome.

If the landscaping sends water towards the wall, the drainage system needs to handle it.

If somebody damages the drainage while installing fence posts, the wall still experiences the consequences.

Over time, homeowners might notice wet areas, soil movement or poor drainage around the structure.

That is why retaining wall and fence planning needs to include what happens around the wall, not just what happens directly underneath the fence.

The visible structure might occupy a narrow strip of the backyard.

Its performance can depend on water coming from much farther away.

Look at the Fence From Both Sides

Fence height is another detail that can fool you on paper.

A standard 1.8 metre fence sounds straightforward.

Yet ground levels can completely change how that same fence feels.

From the lower side of the property, the fence may look tall and private.

Move to the elevated side and it can suddenly feel much lower.

Before locking in the wall and fence levels, stand where the homeowner will actually spend time.

Look from the outdoor entertaining area.

Check the view from the main living space.

Walk along the driveway.

Consider the backyard.

Think about where furniture may eventually sit.

Where appropriate, also consider what a neighbour might see from their side.

Measurements tell you how tall the fence is.

Perspective tells you whether that height actually works.

Think About What Happens Ten Years From Now

Good construction planning should not stop at handover.

Eventually, parts of the property will need maintenance or replacement.

A concrete sleeper retaining wall may still have plenty of life left when an older timber fence needs replacing.

What happens then?

Can someone remove the old fence posts without damaging the retaining wall?

Will there be enough access for the necessary equipment?

Could old footings make the new fence difficult to install?

Can the contractor work without disturbing the drainage behind the wall?

Have we connected two structures unnecessarily even though they may have completely different replacement cycles?

These questions may not feel urgent during construction.

Years later, they can make the difference between a straightforward fence replacement and a much bigger project.

At Conker, we believe a well considered job should make sense long after the day we leave site.

What Good Retaining Wall and Fence Planning Looks Like

The best planned outdoor areas often feel simple once they are finished.

That simplicity usually comes from thinking through the difficult details beforehand.

The retaining wall establishes useful levels.

Privacy works from the places that matter.

Fence posts have enough room underground.

Drainage remains clear.

Gates meet pathways naturally.

Landscaping works with water movement rather than against it.

Future maintenance remains practical.

Nothing feels like an afterthought.

Importantly, achieving that outcome does not always require spending more.

Good planning can actually reduce unnecessary construction and prevent expensive changes later.

At Conker, We Work Backwards From the Finished Property

A structurally sound retaining wall can still create a poor outcome if it sits at the wrong level.

Even a beautifully built fence can disappoint the homeowner when it does not provide the privacy they expected.

Drainage can also perform perfectly until another part of the project interferes with it.

That is why we try to understand the entire area before focusing on one individual structure.

At Conker, our questions usually start with the outcome.

What are we creating?

How will people use the space?

Where will water travel?

What may need to happen here in the future?

Could we simplify anything?

Does the proposed retaining wall actually solve the homeowner’s problem?

Once we understand those answers, the construction decisions become much clearer.

The retaining wall is one part of the project.

The finished property is the project.

Frequently Asked Questions

Should a retaining wall and fence be planned together?

Yes. Retaining wall and fence planning helps coordinate finished levels, privacy, post positions, drainage, gates and future maintenance. Even when different contractors complete each structure, early planning can prevent expensive conflicts later.

Should the retaining wall or fence go in first?

The retaining wall will usually go in first because it establishes the ground levels. However, you should consider the future fence position, height and likely post locations before retaining wall construction begins.

Why can a 1.8 metre fence still feel too low?

Different ground levels change how you experience fence height. A fence that looks tall from the lower side can provide far less privacy when viewed from an elevated house, patio or backyard.

Can fence posts interfere with retaining wall drainage?

Yes. Fence post holes and footings can conflict with retaining wall posts, drainage gravel and agricultural drainage pipe. Planning the likely post positions early gives both structures enough space to work properly.

Do I always need a retaining wall when the ground changes level?

No. The right solution depends on the site, available space, drainage and what you want the finished area to achieve. Sometimes a different layout, changed levels or a smaller wall can create a better result.

Why is drainage important in retaining wall and fence planning?

Water moving behind or around a retaining wall needs a controlled path. Fence footings, landscaping and other construction can interfere with that path if nobody considers the entire area beforehand.

What does Conker look at before recommending a retaining wall?

At Conker, we first look at what the homeowner wants the finished property to achieve. We consider levels, usable space, access, privacy, drainage, water movement, fencing, gates, nearby concrete, landscaping and future plans. From there, we work backwards to determine what the site genuinely needs.

Final Thoughts

If you know a fence will eventually sit above or beside a retaining wall, plan the two together before construction begins.

Different contractors can still build them.

The work can happen at different stages.

However, the decisions need to connect.

Check the finished levels and consider how the fence will feel from both sides.

Plan likely fence post locations before they conflict with the retaining wall structure or drainage.

Think about gates, pathways, driveways and landscaping.

Follow the path water takes during heavy rain.

Consider how someone might replace the fence years from now.

Above all, understand what you actually want the finished area to achieve before deciding how much retaining you need.

Sometimes the answer is a larger wall.

Another property may benefit from a smaller one.

In some situations, changing the layout can solve the problem more effectively.

The retaining wall is not the outcome.

Neither is the fence.

The finished property is the outcome.

Plan that first.

Have a Question?

Have a question or a topic you’d like us to cover? Email us at advice@conker.com.au.