Why does Christchurch cost differently to the rest of the country?

Because of what’s under the section, and what blows across it.

The ground. Christchurch land carries a technical category from the post-earthquake assessment: TC1, TC2 or TC3. TC1 is land where liquefaction damage is unlikely and conventional foundations apply. TC2 expects minor to moderate damage and calls for engineered foundations. TC3 expects moderate to significant damage and needs site-specific geotechnical investigation and specific engineering design. That system was written for houses, so it does not automatically apply to a garden wall. What it does tell you, free, is what kind of ground you are building on. If the house needed a raft slab, a heavy retaining wall or a large paved area on the same site is a conversation with an engineer, not a guess.

The plains versus the hills. Out on the flat, through Rolleston, Lincoln and much of the west, you’re often working over shingle. It drains beautifully and it digs easily, which is money back in your pocket. On the Port Hills you get slope, rock, and access that turns a one-day machine hire into three. Slope is the single biggest multiplier on a Christchurch quote, because it brings retaining, steps and drainage with it.

Water. Parts of the east sit on a high water table and stay wet through winter. Drainage there is not an optional line item, and a paved terrace laid without it will move.

The nor’wester. Shelter stops being a nice idea in Canterbury and becomes a structural element. Hedging, a wall, a screen or a well-placed built element has to go in early, and it needs to be on the plan rather than added later when you work out you can’t sit outside in October.

Where does the money actually go?

Into built things and growing things, and the split surprises people.

The built stuff, paving, walls, decking, steps, driveways, drainage and lighting, usually takes the majority of the budget. It’s construction and it’s priced like construction. Every square metre of it has excavation, base course, drainage and labour under it before anyone lays a single paver.

The growing stuff, the trees, hedging, planting and lawn, is the smaller slice by cost. It’s also the part that improves each year while the paving slowly ages, which makes it the best value line on most quotes.

The mistake to avoid is spending the whole budget on hard surfaces and leaving nothing for planting. A large paved area with a thin band of plants around it looks like a car park with ambitions.

What does the design itself cost?

Starting point is $1,800 to $4,500 for a residential garden, agreed before we start.

Our two packages:

• Concept plan, from $1,800. Includes 3D visuals and full planting details, so you can see and feel the garden before you commit to a thing.
• Full construction plans, from $4,500. Everything a landscaper needs to price and build it properly.

Larger gardens, pool designs and complex sites cost more, but you’ll have a firm number before we start rather than a surprise at the end.

Against a $40,000 Christchurch build that’s a bit over a tenth of the budget, spent before anything gets dug. It buys you the chance to find out that the pool is in the shade, the terrace catches the nor’wester, or the tree you fell in love with will be into the neighbour’s gutters in eight years.

What’s in each package, what separates a concept plan from construction plans, and what pushes a fee above the standard rates: that’s all set out in our New Zealand-wide cost post. 

Some clients take the concept and stop there – get their own contractor to price the build off it. Others go the whole way through. For a straightforward flat section in Rolleston or Lincoln the concept is often enough. On a Port Hills site with retaining and levels, you want the construction set. 

What makes a Christchurch quote jump?

Five things, and you can spot most of them from your own back door.

1. Anything under about a metre of clearance beside the house means barrowing. Barrowing turns a machine job into a labour job, and labour is the expensive part.
2. A one-metre fall across a courtyard means a wall, at least three steps, and somewhere for the water to go. Three trades where you thought you had one.
3. Spoil and old concrete cost money to cart and dump, and the volume is always more than it looks in the ground.
4. Consent triggers. Retaining over 1.5m, or carrying a surcharge like a driveway above it, needs a building consent. So does a deck you can fall more than 1.5m from. Crossing either line adds fees and weeks.
5. Imported soil. Shingle sites and scraped new-build sections often have no topsoil left. Covering 300 square metres at 100mm deep is 30 cubic metres to buy, cart in and spread.

Should you build it all at once?

Not always, and this is where a plan pays for itself twice.

A proper design lets you build in stages without the stages fighting each other. Get the bones in first: levels, drainage, the main structures, and the trees that need years to do anything. Then add the softer detail as budget allows. What you want to avoid is building blind and tearing out year-two work to make room for year-three plumbing. That’s how a budget doubles.

We’re in Christchurch and you’re not. Does that work?

Yes, and it’s most of what we do.

The whole process happens remotely: the consult, the concept, the 3D visuals, the plans. We’ve worked on Christchurch projects including Waltham and Rolleston, and we design gardens for clients anywhere in the world at the same rates, invoiced in NZD.

What we need from you is lots of site photos, house plans if you have them, and a site measure. On a sloping site we can arrange a professional survey. Then you build with a Christchurch contractor who knows Canterbury ground, working off a plan they can price line by line.

Common questions

When should I start the garden on a new build?

Before the house is finished, ideally during the design stage. Levels, drainage, driveway falls and where the machinery sits are all far cheaper to get right while there’s still open ground and a digger on site.

Do these prices include GST?

Our design fees are quoted excluding GST. Contractor pricing varies, so ask any landscaper to confirm on their quote before you compare two numbers.

Do I need a building consent for a retaining wall or a deck?

Often not, but the lines are specific. A retaining wall up to 1.5m with no surcharge above it, and a deck you can’t fall more than 1.5m from, are generally exempt under Schedule 1 of the Building Act. Exempt work still has to meet the Building Code, and resource consent rules are a separate question, so check with Christchurch City Council for your own site.

What’s the cheapest way to make a big difference to a Christchurch section?

Shelter and structure. A hedge or screen on the nor’west side, one well-placed tree, and generous planting beds instead of scattered single plants will change how a section feels for a fraction of what paving costs.

Can I get a rough number before I commit to a design?

Yes. That’s what the free 30-minute call is for. We go through your wish list and your budget, and by the end you’ll know whether the two are in the same postcode and what it’ll take to bring them together.

Christchurch gardens are priced by their ground more than their taste. Find out what’s under the section, put a real number on the build before you fall in love with the paving samples, and the rest of the project gets a lot calmer.