Three quotes landed on the same kitchen table last spring, all for the same retaining wall and terrace job in Newtown. One was $18,400. One was $31,900. One was a single line: “Outdoor landscaping works – $24,000.” As the person the owner had asked to manage the job through to completion, my first task wasn’t picking a number. It was working out whether any of the three had actually priced the same thing.
That single-line quote is the one that should worry you most, and not because of the number attached to it. A price with no breakdown tells you nothing about what happens when the digger hits old fill, or when the council asks for a drainage detail nobody budgeted for. Managing a project well starts with reading a quote the way a project manager reads it: line by line, looking for what’s missing as much as what’s there.
Site preparation and spoil are their own line, always
Clearing a site, removing old structures, and taking excavated soil off-site are separate costs from building the new work. On a sloped section this can be a fifth of the total price before a single block or post goes in. A proper quote states how many cubic metres of spoil are expected to leave the site and what happens to it – reused on-site as fill, or carted away and tipped, which carries its own disposal cost. If a quote just says “site prep included,” ask what that figure assumes for spoil volume, because that assumption is usually where a fixed price quietly becomes a variable one.
Base course and materials need a spec, not an adjective
“Compacted base” is not a specification. A specification names the material – GAP40 base course, for instance – and a compacted depth in millimetres, typically 100mm to 150mm under paving or driveways. The same applies to pipe diameter for subsoil drains, mesh size in a concrete slab, and the grade of timber or steel in a wall. When three quotes use different words for what should be the same layer, that’s where you ask each contractor to itemise the product and thickness, not just the square metreage.
PC sums and contingency are not the same thing
A PC sum, or prime cost sum, is a placeholder for an item not yet chosen – a certain style of paver, a specific gate hardware – priced as an allowance until you decide. Contingency is a separate allowance for the unknown: what the digger might find below the topsoil that nobody could see at quoting stage. Some contractors fold both into one number, which makes it impossible to tell whether you’re carrying risk or just a delayed decision. Ask for them listed apart, and ask what percentage the contingency line represents – 10% to 15% of the excavation and groundworks total is a reasonable range on a sloped Wellington section.
Variations: how a changed instruction gets priced
Every job on real ground changes at least once. The quote should say how a variation is priced before work starts on it – a day rate, a materials-plus-margin rate, or a fresh quote for the changed scope – and whether that variation needs your written agreement before the contractor proceeds. Without that clause, “we hit rock” becomes a number you see for the first time on the final invoice.
GST: read the number twice
New Zealand quotes should state plainly whether the figure is GST inclusive or exclusive. A $20,000 quote excluding GST and a $22,500 quote including it are the same price. Comparing three quotes without checking this line first is the fastest way to think one contractor is dearer than they are.
None of this is about distrust. It’s about being able to hold two quotes side by side and know you’re comparing the same job. The next step – actually getting quotes worded so they can be compared – is its own exercise, and worth doing before you ring anyone: read how to get comparable quotes for outdoor work before you send out the first request. MBIE’s guidance on building consents and residential building work is a useful check for anything involving structures over the consent threshold.
Frequently asked questions
Should a landscaping quote list spoil removal separately? Yes. Spoil volume and disposal cost vary with what the excavation finds, so it should be its own line rather than folded into a single “site works” figure.
What is a PC sum on a landscaping quote? A prime cost sum is a placeholder allowance for an item not yet chosen, such as a paving style, priced provisionally until you select the actual product.
Does a landscaping quote have to state GST separately? It should state clearly whether the total is GST inclusive or exclusive, since comparing quotes without checking this can make prices look further apart than they are.