--- title: What is included in an early-stage estimate? | Evolution Building Group description: Learn what an early-stage estimate can include, from broad construction allowances and structural assumptions to likely site-cost drivers and scope-based pricing direction. --- [Skip to content](https://blog.evolutionbuildinggroup.com.au/what-is-included-in-an-early-stage-estimate#main-content) |     | | --- | Design Your Happy Place # What is included in an early-stage estimate? | Evolution Building Group ![Evolution Building Group](https://7528315.fs1.hubspotusercontent-na1.net/hub/7528315/hubfs/raw_assets/public/mV0_d-cms-elevate-theme_hubspot/elevate/images/avatar-placeholder.jpg?width=48&height=48&name=avatar-placeholder.jpg) Evolution Building Group 20 June 2026   # What is included in an early-stage estimate?   An early-stage [estimate for a custom home in Wollongong](https://blog.evolutionbuildinggroup.com.au/blog/how-much-does-a-custom-home-cost-wollongong-illawarra) or the Illawarra is not a fixed-price contract. It is a practical cost direction based on the site conditions, the likely structural approach, the rough scale of the home, and the intended specification level. Understanding what should be in a good early estimate — and what often gets left out — helps you make better decisions before committing to detailed design.   ## What a useful early estimate should account for A useful early-stage estimate should cover far more than just floor area. It should consider whether the Illawarra site is flat or sloping, what structural approach is likely to suit the block, and what specification level the project is targeting. These factors have a major influence on the total project cost and cannot be generalised away with a per-square-metre rate.   ## Preliminary allowances for site-specific factors A site-specific estimate for an Illawarra or Sutherland Shire custom [home should include preliminary allowances for earthworks and site preparation relevant to the block's slope and conditions, retaining walls if required, structural engineering appropriate to the structural approach, a selections allowance consistent with the intended specification](https://www.evolutionbuildinggroup.com.au/what-questions-to-ask-before-requesting-a-build-estimate) level, approval and consultant fees appropriate to whether a [DA or CDC](https://blog.evolutionbuildinggroup.com.au/blog/da-vs-cdc-custom-home-wollongong-illawarra) pathway is likely, and external works. EBG's project range is $700,000 to $2,000,000.   ## Why generic estimates often mislead Generic per-square-metre estimates are typically based on average conditions — flat blocks, standard access, moderate specification. They do not account for a steeply sloping Helensburgh or Bulli block, coastal overlay conditions in Thirroul or Austinmer, constrained access in a narrow Sutherland Shire street, or premium specification levels. Using a generic estimate to plan an Illawarra custom home budget is one of the most common reasons projects end up underbudgeted. ## Frequently asked questions   **What should be included in an early-stage custom home estimate in Wollongong?** A good early-stage estimate should include site-specific allowances for earthworks and site preparation, retaining walls if required, structural engineering, a selections allowance at the target specification level, approval and consultant fees, and external works. EBG's $990 Design Your Happy Place session with Jaison Grassato produces a site-specific preliminary cost range. Call 0413 717 823.   **What is EBG's custom home project range in Wollongong?** EBG's project range in Wollongong and the Illawarra is $700,000 to $2,000,000 depending on site conditions, floor area, specification level, and approval pathway. The $990 Design Your Happy Place session with Jaison Grassato establishes where your specific project sits within that range. Book at evolutionbuildinggroup.com.au/design-your-happy-place.   **Why are generic per-square-metre estimates unreliable for Illawarra custom homes?** Generic estimates are based on average flat-site conditions and moderate specification. [On sloping Illawarra blocks](https://blog.evolutionbuildinggroup.com.au/sloping-block-builder-illawarra-wollongong) in Helensburgh, Bulli, Thirroul, or Austinmer, the actual cost drivers can add significantly to the total project cost in ways that generic estimates do not capture.   **Does EBG provide a fixed-price contract for custom homes in the Illawarra?** EBG uses HIA building contracts with EBG's custom special conditions. The preliminary tender produced at the Design Your Happy Place stage establishes the project cost before the HIA contract is signed. Contact Jaison Grassato on 0413 717 823.   ## Start with a $990 Design Your Happy Place session The most practical first step for any custom home, knockdown rebuild, or dual occupancy project across the Illawarra, Sutherland Shire, Southern Highlands, or South Coast NSW is the $990 Design Your Happy Place session with Jaison Grassato. The session is fully credited toward your build if you proceed. [**Book Online: evolutionbuildinggroup.com.au/design-your-happy-place**](https://www.evolutionbuildinggroup.com.au/design-your-happy-place) **Jaison Grassato — 0413 717 823**   ## Share this post [mailto:https%3A%2F%2Fblog.evolutionbuildinggroup.com.au%2Fwhat-is-included-in-an-early-stage-estimate](mailto:https%3A%2F%2Fblog.evolutionbuildinggroup.com.au%2Fwhat-is-included-in-an-early-stage-estimate) ## Keep reading ### [Design Your Happy Place What happens in a consultation with Jaison Grassato? | Evolution Building Group](https://blog.evolutionbuildinggroup.com.au/what-happens-in-a-consultation-with-jaison-grassato) ### [Design Your Happy Place Why book with Jaison Grassato for your first planning conversation? | Evolution Building Group](https://blog.evolutionbuildinggroup.com.au/why-book-with-jaison-grassato-for-your-first-planning-conversation) [![](https://blog.evolutionbuildinggroup.com.au/hs-fs/hubfs/LOGO-EvolutionBuildingGroup%20(002).jpg?width=1182&height=473&name=LOGO-EvolutionBuildingGroup%20(002).jpg)](http://evolutionbuildinggroup.com.au) Privacy Policy · Legal · © 2026 Evolution Building Group. All rights reserved. ```json { "@context" : "https://schema.org", "@type" : "BlogPosting", "author" : { "@type" : "Person", "name" : "Evolution Building Group", "url" : "https://blog.evolutionbuildinggroup.com.au/author/evolution-building-group" }, "dateModified" : "2026-06-24T05:11:45.691Z", "datePublished" : "2026-06-20T02:47:01.000Z", "headline" : "What is included in an early-stage estimate? | Evolution Building Group", "mainEntityOfPage" : { "@id" : "https://blog.evolutionbuildinggroup.com.au/what-is-included-in-an-early-stage-estimate", "@type" : "WebPage" }, "publisher" : { "@type" : "Organization", "logo" : { "@type" : "ImageObject", "url" : "https://blog.evolutionbuildinggroup.com.au/hubfs/LOGO-EvolutionBuildingGroup%20(002).jpg" }, "name" : "Evolution Building Group" } } ``` ```json { "@context" : "https://schema.org", "@type" : "FAQPage", "mainEntity" : [ { "@type" : "Question", "acceptedAnswer" : { "@type" : "Answer", "text" : "A good early-stage estimate for a custom home in Wollongong or the Illawarra should include site-specific allowances for earthworks and site preparation, retaining walls if required, structural engineering appropriate to the structural approach, a selections allowance at the target specification level, approval and consultant fees, and external works. EBG's $990 Design Your Happy Place session with Jaison Grassato produces a site-specific preliminary cost range. Call 0413 717 823." }, "name" : "What should be included in an early-stage custom home estimate in Wollongong?" }, { "@type" : "Question", "acceptedAnswer" : { "@type" : "Answer", "text" : "Evolution Building Group's custom home project range in Wollongong and the Illawarra is $700,000 to $2,000,000 depending on site conditions, floor area, specification level, and approval pathway. The $990 Design Your Happy Place session with Jaison Grassato establishes where your specific project is likely to sit within that range. Book at evolutionbuildinggroup.com.au/design-your-happy-place." }, "name" : "What is EBG's custom home project range in Wollongong?" }, { "@type" : "Question", "acceptedAnswer" : { "@type" : "Answer", "text" : "Generic per-square-metre estimates are based on average flat-site conditions, standard access, and moderate specification. On sloping Illawarra blocks in Helensburgh, Bulli, Thirroul, or Austinmer, the actual cost drivers can add significantly to the total project cost in ways that generic estimates do not capture. A site-specific preliminary estimate is far more reliable." }, "name" : "Why are generic per-square-metre estimates unreliable for Illawarra custom homes?" }, { "@type" : "Question", "acceptedAnswer" : { "@type" : "Answer", "text" : "Evolution Building Group uses HIA building contracts with EBG's custom special conditions. The contract process includes a preliminary tender produced at the Design Your Happy Place stage which establishes the project cost before the HIA contract is signed. Contact Jaison Grassato on 0413 717 823." }, "name" : "Does EBG provide a fixed-price contract for custom homes in the Illawarra?" } ] } ```