When a couple decides to sell the house they bought together, the building report is often the first time anyone looks hard at the parts of the section that nobody thinks about day to day. Retaining walls are a classic example. Then a buyer’s inspector writes three lines about “evidence of movement” and two people already finding it hard to agree have a new problem.
What inspectors actually look for
A standard pre-purchase inspection is visual. The inspector is not digging behind the wall or running engineering calculations; they are looking for signs that something is not right. The usual notes fall into a handful of categories:
- Lean or bulge. A timber pole wall that has tilted forward, or a block wall with a belly in the middle, suggests the soil behind it is pushing harder than the wall was built to take.
- Rot at ground level. Older timber walls, especially those built before treated posts were standard, often soften where the posts meet the soil.
- Cracking in masonry. Stepped cracks along mortar lines, or cracks wide enough to fit a coin into, get attention.
- Poor drainage. No weep holes, blocked weep holes, or water pooling at the base. Water is behind most retaining wall failures.
- Height and consent questions. Walls over about 1.5 metres, or walls holding up a driveway or building, generally needed a building consent. Inspectors often flag that a wall “may require consent” and suggest checking the council property file.
In Canterbury there is an extra layer. Many sections were affected by the 2010–2011 earthquakes, and some walls were repaired, some were replaced, and some were simply left. A buyer reading a Christchurch report will often want to know which of those it was.
Why it matters more when owners have separated
In an ordinary sale, the vendors look at the report, talk it over at the kitchen table, and decide whether to fix something, lower the asking figure, or leave it for the buyer. When the owners are no longer living together, that conversation is harder.
A defect that would normally be a minor negotiating point can become a sticking point between the owners. The practical risk is that the wall becomes the reason the sale drags on for months, which usually costs both people more than the repair would have.
Getting a clear picture before deciding anything
The building report is a starting point, not a verdict. Before deciding whether to repair, the sensible first step is usually to get someone who builds and repairs retaining walls to look at the specific issue and explain what it would take to fix. For owners in Canterbury, talking to local Christchurch retaining walls builders gives a realistic idea of whether the wall needs a full rebuild, a partial repair, or simply better drainage. A written scope with a cost range is far easier for two separated owners to agree on than a vague line in someone else’s report.
It also helps to pull the council property file. This shows whether the wall was consented, whether there is a code compliance certificate, and whether any earthquake repair work is recorded. Councils supply these for a modest fee, usually within a week or two. Having this on hand means both owners are working from the same facts.
Repair, discount or disclose
Once the picture is clear, there are broadly three paths:
- Repair before listing. Works well when the fix is straightforward, such as replacing a few rotten posts or clearing drainage, and when both owners can agree on who pays. Simple timber repairs might run from a few thousand dollars; a full engineered rebuild on a sloping section can run well into five figures. Costs vary a lot with access, height and soil.
- Adjust the asking figure. Sometimes the cleaner option is to price the issue into the sale. This avoids the owners having to coordinate tradespeople and payments while separated.
- Disclose and leave it. If the wall is old but stable, a clear disclosure supported by a tradesperson’s note may be enough to reassure buyers.
Whichever path is chosen, keep everything in writing: the inspector’s comments, any quotes, and emails between the owners about who agreed to what. How the cost of a repair is shared between separating owners is a property matter, and each person should get independent advice on that side of things rather than trying to settle it informally over text.
Frequently asked questions
Will a leaning retaining wall stop a house from selling? Rarely on its own. Most buyers will still proceed if they understand the cost to fix it, though they may ask for a lower figure or a repair before settlement.
Do all retaining walls need a building consent? Not all. Generally, taller walls and those supporting a building, driveway or other load need consent, but the rules vary, so check with the local council and the property file.
Who pays for repairs if the owners have separated? That depends on the owners’ arrangements and their wider property settlement, so each person should get independent advice rather than relying on an informal agreement.