Can I Prepare a Materials List for a New Garden Shed Myself?

Yes, preparing a materials list (sometimes called a bill of quantities or take-off) for a garden shed is something most handy homeowners can tackle themselves. With careful measuring, a clear plan, and a methodical approach, you can put together a solid list that helps you budget accurately and avoid costly trips back to the hardware store. That said, there are a few NZ-specific rules around consents and construction that are worth understanding before you start.

Start With a Clear Plan or Drawing

Before you can list a single nail, you need a design. Even a simple hand-drawn sketch with dimensions will do. Decide on:

• Floor area and height — these determine framing, cladding, and roofing quantities
• Roof pitch and style — gable, skillion, or lean-to all use different amounts of material
• Door and window openings — these affect framing and cladding calculations
• Foundation type — concrete slab, timber bearers on pads, or a proprietary steel base

If you're buying a kit-set shed, the supplier will usually provide a materials list already. For a custom-built shed, you'll need to work it out yourself or get help.

Do You Need a Building Consent?

This is a critical first step. In New Zealand, some small sheds are exempt from building consent under Schedule 1 of the Building Act 2004 — but the rules have specific limits around floor area, height, and proximity to boundaries. These exemptions can change, and your local council may have additional requirements.

Always confirm with your local council before you build, even if you believe your shed is exempt. Check MBIE Building Performance for general guidance on Schedule 1 exemptions, and ring your council to confirm what applies to your site.

If consent is required, a licensed building practitioner or draughtsperson will need to produce compliant plans — and a quantity surveyor can help you prepare a formal bill of quantities from those plans.

How to Prepare Your Materials List

Work through the shed systematically, section by section. A good order to follow is:

1. Foundation

• Number and size of concrete pads or timber bearers
• Concrete volume (length × width × depth in metres = cubic metres)
• Any DPC (damp-proof course) membrane

2. Floor Framing

• Timber bearers and joists (size, spacing, and total linear metres)
• Flooring sheet material — typically 17 mm or 19 mm H3.2 treated plywood or particleboard (calculate area in m², then divide by sheet size — standard sheets are 2400 × 1200 mm)

3. Wall Framing

• Bottom plates, top plates, and studs (usually 90 × 45 mm H1.2 treated timber at 600 mm centres)
• Calculate total wall length, multiply by two for plates, then count studs
• Add noggings, lintels over openings, and trimmers

4. Roof Framing

• Rafters, ridge board, and ceiling ties if applicable
• A skillion roof is simpler to calculate than a gable — use Pythagoras to find rafter length from run and pitch

5. Cladding and Roofing

• Wall cladding area (total wall area minus openings), plus 10–15% waste allowance
• Roofing iron or corrugated steel — measure roof area and add overhang
• Flashings, ridge cap, and fixings

6. Doors, Windows, and Hardware

• Door frame, door leaf or pre-hung unit
• Window unit if required
• Hinges, latch, and lock

7. Fixings and Consumables

• Nails, screws, joist hangers, and framing anchors
• A general rule of thumb: allow around 5–10% of your structural timber cost for fixings
• Sealants, paint or stain — check Resene or Dulux for suitable exterior timber coatings

Use a Simple Spreadsheet

Organise your list in a table like this:

This format makes it easy to get quotes from Mitre 10, Bunnings, or PlaceMakers.

Common Mistakes to Avoid

• Forgetting waste — always add 10–15% to sheet materials and 5–10% to timber
• Ignoring fixings — these add up quickly and are easy to overlook
• Not checking timber treatment levels — ground-contact timber must be H4 treated (or H5 in some situations such as saltwater exposure); above-ground framing is typically H1.2 or H3.2 depending on exposure
• Underestimating roofing accessories — flashings, screws, and sealant are often forgotten

When to Call a Professional

If your shed is large, complex, or requires a building consent, it's worth engaging a licensed building practitioner (LBP) for the design and construction, and a quantity surveyor (QS) to prepare a formal bill of quantities. A QS will catch errors, identify specification issues, and give you a more accurate budget — potentially saving you money in the long run. You can find qualified local tradespeople, including quantity surveyors and builders, on tradedirectory.co.nz.

For any electrical work inside the shed (power outlets, lighting), this is restricted electrical work and must be carried out by a registered electrician — see EWRB for details. Similarly, any plumbing connections are restricted work under the PGDB.

Sources & Further Reading

• MBIE Building Performance — Schedule 1 exemptions
• Licensed Building Practitioners (LBP)
• BRANZ — building guidance and good practice
• PlaceMakers — timber and building supplies
• Electrical Workers Registration Board
• Plumbers, Gasfitters and Drainlayers Board