Top Retaining Walls Christchurch takes the consent side of a retaining wall off your hands in Christchurch. Most owners find out too late that their wall needed a consent, and fixing that afterwards costs far more than doing it in order. We work out which side of the line your job sits on at the first site visit.
Schedule 1 of the Building Act 2004 exempts a retaining wall when two things are both true. It retains no more than 1.5m depth of ground, and it does not support any surcharge or any load beyond the ground itself. Vehicles and buildings are the obvious surcharges. Sloping fill above the wall counts too, and that is the one that catches people.
Break either condition and you need a building consent from Christchurch City Council, and that means a chartered professional engineer's design and a producer statement. The wall also has to meet the Building Code either way, including clauses for structure, durability and safety from falling, even when it is exempt from consent.
| Exempt | Retains 1.5m or less of ground and carries no surcharge |
|---|---|
| Not exempt | Over 1.5m, or any driveway, building, pool or sloping fill above |
| Design | Chartered professional engineer and a producer statement |
| Building Code | Applies even when consent is not required |
| Christchurch City | Extra scrutiny on liquefaction and slope hazard sites |
| Selwyn District | Rolleston, Lincoln, Prebbleton and surrounds |
| Waimakariri District | Kaiapoi, Rangiora, Woodend and surrounds |
Christchurch City Council pays extra attention to land with a liquefaction history and to slope hazard areas. An application on a TC3 section in the east and an application on a Port Hills slope rarely take the same route, and both take longer than a straightforward flat site in Fendalton or Bishopdale.
If your property sits outside the city boundary the rules are the same but the council is not. Rolleston, Lincoln and Prebbleton go through Selwyn District Council. Kaiapoi, Rangiora and Woodend go through Waimakariri District Council. We deal with all three.
We measure the site and work out the retained height and any surcharge. We brief the engineer and get the design and producer statement. We put the application together, lodge it, answer the council's questions, book the inspections and meet the inspector on site.
You get told where it is up to at each stage. The one thing we cannot control is council processing time, and applications with missing information are the ones that stall.
Two short walls with real horizontal separation between them can do the same job as one tall wall and stay inside the exemption, as long as no wall imposes a surcharge on the one below. MBIE guidance uses exactly this example with three 1.2m crib walls.
This is not a loophole, it is a design decision, and it often costs less than one engineered wall while giving you planting terraces you would not otherwise have. It only works if the geometry allows it, and we will tell you honestly when it does not.
Every wall we build gets drainage. At least 300mm of clean free draining metal, a perforated coil at the base running to a real outlet, and geotextile over the top so silt cannot block it. It is not an optional line on our quotes.
Not on height alone. You do need it if anything loads the ground above the wall, including a driveway, a parked car, a building or fill that slopes up behind it.
You apply for a certificate of acceptance, which is a retrospective process. It is more work and more cost than a normal consent, and the council may want parts of the wall opened up so it can be inspected.
We put the application together and lodge it. The owner still signs as the applicant, but you do not have to assemble any of it.
Our old wall was rotten right through and leaning into the neighbour's place. They pulled the lot out, put proper drainage behind the new one and had it finished in three days. Swept the site clean every afternoon before they left too. Tidiest crew we have ever had here by a long way.
They sorted the consent, which was the bit I was dreading. Dealt with the council so I never had to, and kept me in the loop the whole way through. The driveway sits right above it and has not shifted a millimetre.
Steep section, shocking access, and they still made it look easy. They suggested two smaller walls instead of one big one, which saved us thousands in engineering fees. The terrace in between is now my favourite part of the whole garden.
Call [PHONE] or answer three quick questions. The site visit and the written quote cost you nothing.
