Yes, you can create your own bill of quantities (BOQ) for a small renovation — and for straightforward projects, a DIY approach can save you money and give you a clearer picture of costs before work begins. That said, accuracy matters enormously: an incomplete or poorly structured BOQ can lead to budget blowouts, disputes with tradespeople, or missed items that derail your project. Here's what you need to know to do it well.
What Is a Bill of Quantities?
A bill of quantities is a detailed document that lists every material, labour task, and sometimes plant or equipment needed to complete a building or renovation project. It breaks the work down into measurable line items — for example, square metres of flooring, linear metres of skirting board, or the number of doors to be hung. Tradespeople and contractors use a BOQ to price work consistently, so you can compare quotes on an apples-to-apples basis.
For a small renovation — say, a bathroom refresh, a kitchen update, or a single-room extension — a simplified BOQ is entirely achievable without professional help, provided you're methodical.
What to Include in Your BOQ
A well-structured DIY BOQ should cover the following sections:
- Project description — address, scope of work, and any relevant consent information
- Demolition and removal — what's being stripped out and how waste will be disposed of
- Structure and building fabric — framing, linings, insulation, roofing (if applicable)
- Wet areas — waterproofing, tiling, fixtures (bathrooms and kitchens especially)
- Finishes — painting, flooring, joinery, skirting, architraves
- Services — electrical, plumbing, and gas (note: these are restricted work — see below)
- External works — decking, paths, fencing if relevant
- Contingency — typically 10–15% added to your subtotal to cover unknowns
Use a spreadsheet with columns for: item description, unit of measurement (m², m, each, etc.), quantity, unit rate, and total cost.
How to Measure Up Accurately
Accurate measurement is the foundation of a reliable BOQ. Take your time with this step.
Key measuring tips
- Use a quality tape measure or, better yet, a laser distance measurer for larger spaces
- Sketch a simple floor plan with dimensions before you start listing items
- For walls, measure height × width and subtract door and window openings
- For flooring, calculate the room area and add 10% waste for tiles or timber (more for diagonal layouts)
- For paint, check the coverage rate on the product datasheet — Resene and Dulux both publish these online
- Double-check all measurements — measure twice, enter once
Estimating Costs and Labour
Once you have quantities, you need unit rates. For materials, get current pricing from suppliers like Bunnings, Mitre 10, or PlaceMakers. Keep in mind that prices fluctuate, so note the date you checked them.
For labour, rates vary by trade, region, and complexity. As a very rough guide only, labour is often quoted per unit (e.g., per m² of tiling, per door hung) or as a day rate. The best approach is to get at least two or three quotes from licensed tradespeople and use your BOQ as the basis for those conversations — it shows you've done your homework and helps tradespeople price accurately.
For plasterboard and stopping work, GIB publishes technical guides that can help you estimate lining quantities.
Restricted Work — What You Cannot DIY
This is critical. In New Zealand, certain work is legally restricted to licensed professionals, regardless of how small the job is:
- Electrical work — any wiring, new circuits, or connections to the mains must be carried out by a registered electrician. Check the Electrical Workers Registration Board (EWRB) for what's permitted.
- Plumbing and drainlaying — connections to water supply, drainage, and sanitary fixtures must be done by a licensed plumber or drainlayer registered with the Plumbers, Gasfitters and Drainlayers Board (PGDB).
- Gas fitting — always a licensed gasfitter.
You can include these items in your BOQ as line items, but the actual work must be quoted and carried out by the appropriate licensed professional. Never attempt restricted work yourself — it's illegal, dangerous, and can void your insurance.
Building Consent Considerations
Some renovation work requires a building consent from your local council before work begins. Schedule 1 of the Building Act lists certain exemptions for minor work, but the rules can be nuanced. Always confirm with your council whether your project needs consent — don't assume it's exempt. MBIE Building Performance has clear guidance on consent requirements and the NZ Building Code, including clauses like E3 (internal moisture), G12 (water supplies), and G13 (foul water) that are particularly relevant to bathroom and kitchen renovations.
If consent is required, your BOQ may need to align with consented plans and specifications.
Common DIY BOQ Mistakes to Avoid
- Forgetting fixings, adhesives, and consumables (these add up)
- Underestimating waste and offcuts on materials
- Leaving out site preparation and protection costs
- Not accounting for GST — check whether supplier prices include it
- Ignoring council fees and consent costs if applicable
- Skipping the contingency allowance
When to Call a Professional
For larger or more complex renovations — multi-room projects, structural work, or anything involving significant consent documentation — it's well worth engaging a registered quantity surveyor (QS). A QS will produce a comprehensive, accurate BOQ that can save you far more than their fee by preventing costly errors and disputes. They can also provide independent cost advice if you're unsure whether a contractor's quote is reasonable.
You can find qualified quantity surveyors and other building professionals in your area right here on tradedirectory.co.nz.