Enter your email Address

LookUpStrata

Empowering Strata Together

advert Lannock strata finance
Australia's Top Property Blog Dedicated to Strata Living
  • Home
  • What is strata?
    • Strata Legislation – Rules and ByLaws
    • What is Strata?
    • Glossary of NSW Strata Terms and Jargon
    • Understand Strata Management with this Five-Minute Guide
    • Cracking the Strata Fees Code
    • Strata Finance
  • Strata Topics
    • Strata Information By State
      • New South Wales
      • Queensland
      • Victoria
      • Australian Capital Territory
      • South Australia
      • Tasmania
      • Western Australia
      • Northern Territory
    • Strata Information By Topic
      • By-Laws & Legislation
      • Smoking
      • Parking
      • Noise & Neighbours
      • Insurance
      • Pets
      • Your Levies
      • New Law Reform
      • Maintenance & Common Property
      • Committee Concerns
      • NBN & Telecommunications
      • Building Defects
      • Renting / Selling / Buying Property
      • Strata Managers
      • Building Managers & Caretakers
      • Strata Plan / Strata Inspection Report
      • Apartment Living Sustainability
    • Strata Webinars
      • NSW Strata Webinars
      • QLD Strata Webinars
      • VIC Strata Webinars
      • ACT Strata Webinars
      • SA Strata Webinars
      • WA Strata Webinars
    • Upcoming and FREE Strata Events
  • Blog
    • Newsletter Archives
  • The Strata Magazine
    • The NSW Strata Magazine
    • The QLD Strata Magazine
    • The VIC Strata Magazine
    • The WA Strata Magazine
  • Site Sponsors
  • About Us
    • Testimonials for LookUpStrata
  • Help
    • Ask A Strata Question
    • Q&As – about the LookUpStrata site
    • Sitemap
Home » Maintenance & Common Property » Maintenance NSW » NSW: Can a builder double their invoice with a costs plus contract?

NSW: Can a builder double their invoice with a costs plus contract?

Published April 30, 2026 By Dominic Dodwell Leave a Comment Last Updated April 30, 2026

Share with your strata community

  • Share
  • LinkedIn
  • Email

Question: Our builder suggested a costs plus building contract and quoted $80K. Three weeks later, he presented us with a claim of $160K with little evidence of expenses. Are we required to pay?

Does a “costs plus” building contract mean we pay actual costs plus a fee?

A builder did concrete cancer remedial works. He presented a costs plus building contract and quoted $80K. Three weeks later, he presented us with a claim of $160K. His evidence of costs consists of photos of the works and empty concrete bags. He refuses to show us receipts, and his claim does not include any line items for labour. Instead, his bags of cement cost ~$550 each.

Are we entitled to see his costs? How do we dispute the claim?

Answer: This is a good example of why project managers are essential.

Cost plus is a broad term and may be misrepresented, depending on who uses it and their angle when using the term.

  1. It can be a transparent means of tracking actual cost and guaranteeing a contractor their agreed margin, for which they will present actual invoices as evidence and an invoice with their agreed markup. Typically, the markup is limited/lower as the risk to the contractor is low, and their margin is guaranteed.
  2. It may be meant as do-and-charge. In this instance, it sounds like there should have been an agreed schedule of rates for concrete repairs (should be per litre of repair with a minimum limit). With that, the contractors should provide details of the areas being repaired and demonstrate, with supporting evidence, the litres applied to make the repairs. Typically, in such a project, an engineer is involved and should be able to verify the claims based on the areas and depth of the repairs undertaken.

If there is neither transparent evidence of cost, nor a fixed schedule of rates to bill against, you are in a bit of a predicament. Given the size of the numbers, it may be worthwhile engaging a quantity surveyor to assess the claim made by the builder and ensure all parties are fair and reasonable in their approach. If an engineer is acting on behalf of the owners corporation, they may be able to assist.

Note, pending which contract the works are being managed by, the owners need to ensure not to default on the contract in the interim. If unsure, I suggest the owners corporation obtain legal advice and comply with the Security of Payment Act and other legislation.

This is a good example of why project managers are essential. Such works would never be permitted to progress to such an extent without understanding of the works and informing the client of budgets, etc., accordingly. To set up a project for success and allow for management of expectations:

  • Obtain an engineer’s scope of works from the outset (even if minimal work is required, a condition report and basic specification should be the minimum that quotes are based on as it allows for quantification of the project),
  • Undertake a fair tender process,
  • Have a construction industry contract drafted, such as AS4000 or AS4905 (Note: Master Builders or other industry contracts are skewed in favour of contractors),
  • Engage professional representation in the form of an independent project manager / superintendent to manage the contract, and the project works through to defect management and completion.

Dominic Dodwell
Valen Projects
E: dominic@valenprojects.com.au
P: 0488 666 682

Share with your strata community

  • Share
  • LinkedIn
  • Email

About Dominic Dodwell

With an education in multi-disciplinary engineering and project management and 14 years of experience in the facilities/asset/project management sectors, Dom has worked on an extensive diversity of projects, assets, and properties. This exposure provides an essential understanding of best practice applications of proactive maintenance, reactive repairs, and capital works upgrades to any asset or building.
Valen specialises in the management of complex strata projects including Fire Safety Upgrades, Remedial Upgrades, Defect Management Claims, and Sustainability Upgrades.
Our focus is to empower owners with tools and knowledge to make informed decisions on their projects and ensure fit-for-purpose and high-value results.

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

Search For Strata Answers

  • Advert Stratabox
  • StrataBox Advert
Subscribe banner

Why Our Community Trusts Us

"LookUpStrata should be compulsory reading for every member of a Body Corporate Committee. It provides the most understandable answers to all the common (and uncommon) questions that vex Body Corporates everywhere. Too often Committee members do not understand what Body Corporates are legally able to do and not do. LookUpStrata helps educate everybody living in a Body Corporate environment for free." John, Lot Owner

"It's the best and most professional body corporate information source a strata manager could have! Thanks to the whole team!" MQ, Strata Manager

"I like reading all the relevant articles on important issues on Strata living that the LookUpStrata Newsletter always effectively successfully covers"
Carole, Lot Owner

"Strata is so confusing and your newsletters and website are my go-to to get my questions answered. It has helped me out so many times and is a fabulous knowledge hub." Izzy, Lot Owner

Explore Most Read Topics

  • Contact a Strata Specialist on the LookUpStrata Directory
  • Ask Us A Strata Question
  • New South Wales
  • Queensland
  • Victoria
  • Australian Capital Territory
  • South Australia
  • Tasmania
  • Western Australia
  • Northern Territory
  • ByLaws & Legislation
  • Smoking
  • Parking
  • Noise & Neighbours
  • Insurance
  • Pets
  • Levies
  • Law Reform
  • Maintenance & Common Property
  • Committee Concerns
  • NBN & Telecommunications
  • Building Defects
  • Renting / Selling / Buying
  • Strata Managers
  • Building Managers and Caretakers
  • Strata Reports / Plans
  • Sustainability

Latest Q&A Comments

  • Liza Admin on NSW: Can a Disabled Parking Space Be Locked for Exclusive Use in Strata?
  • Mary Rose on TAS: Strata Insurance Tasmania – for a small strata scheme
  • Sylvie E Comeau-Hall on NSW: Do solar panels affect strata building insurance?
  • Peter Cavanagh on NSW: Is a postal ballot required for committee elections
  • Nikki Jovicic on NSW: Can You Use Your Garage for Apartment Storage?
  • Nikki Jovicic on VIC: Audits of Owners Corporation financial statements – not all audits are the same
  • Nikki Jovicic on VIC: Strata parking problems in owners corporations
  • Nikki Jovicic on WA: When does interest apply to unpaid strata levies in WA?
  • KELLE WHALAN on NSW: Can You Use Your Garage for Apartment Storage?
  • Lynda on QLD: Who pays for tv antenna replacement in strata duplexes: Lot owner or body corporate responsibility?

Quick User Login

Log In
Register Lost Password

WEBSITE INFORMATION

  • Privacy Policy
  • Terms and Conditions of Use
  • Terms of Use for Comments and Community Discussion
  • Advertising Disclosure
  • Sitemap

ASK A STRATA QUESTION

You’ve Found Strata Help!

Ask a strata, owners corporation or body corporate question and we will do our best to source a useful response from our network of strata professionals around Australia. Submit your question here.

Subscribe NOW

Disclaimer

The opinions and/or views expressed on the LookUpStrata site, including, but not limited to, our blogs and comments, represent the thoughts of individual bloggers and our online communities, and not those necessarily of LookUpStrata Pty Ltd. In all instances, information should not be taken as advice and independent legal advice should be consulted.

CONTACT US VIA EMAIL

Copyright © 2026 · LookUpStrata ® Pty Ltd · All rights reserved