“If you can’t hit 0.6 ACH on a brand-new build, you probably shouldn’t be building.”
Let’s stop tip-toeing around the reality of the Australian housing market. We are throwing up volume-built boxes and high-density apartments that are practically end-of-life before they’ve even seen their first winter. We sat down with Linden Thorley, architect, Passive House designer, and chair of the Australian Passive House Association Retrofit Committee.
We take a look into why retrofitting the existing 9.5 million homes in Australia is the single biggest business opportunity for trades over the next decade. Linden walks us through the differences between a cosmetic renovation and a high-performance retrofit, detailing how his team utilises the PHPP (Passive House Planning Package) to model data and manage moisture, insulation, and ventilation risks case-by-case.
We don't hold back on the real pain points of the industry either. We talk about the skyrocketing costs of business insurance, why Australian labour rates are fundamentally shifting project costs, and how to structure building contracts using provisional sums for airtightness so builders aren't crushed by unexpected site variations.
Linden also breaks down his frustrations with legacy bank valuations that prioritise bloated 300-square-meter floor plans over highly efficient, smaller family homes.
Finally, we hit the political wall: how heritage advisors and council planners are actively preventing energy efficiency upgrades, and the clever, practical drawing tricks
CHAPTER MARKERS
00:00 – Introduction
02:08 – The Passive House Association Retrofit Committee & Playbook
04:12 – Finding the Ideal Market: How Long Does the Shift Take?
05:45 – Passive House as a Design-Agnostic Calculation Tool
07:11 – Can a House Be Great If It Doesn’t Reach Certified EnerPHit?
09:00 – Retrofitting Multi-Story Blocks vs. Standard Residential
10:38 – Managing Airtightness Expectations with the Builder
13:36 – How to Contract for Airtightness: The Provisional Sum Solution
15:21 – Dealing with Double Brick and Suspended Timber Floors
16:23 – The Spray Foam Debate in Subfloors vs. Walls
18:41 – The New Build Advantage vs. Retrofit Blind Spots
19:16 – A Case Study: Turning a 25 ACH House into an 8 ACH Home
22:27 – Threading Centralized MVHR Systems Through Bulkheads
23:28 – The Necessity of the ECI Process for Architects
26:16 – Why Don’t We Just Knock Them All Down?
27:43 – Renovation vs. Extension vs. Retrofit
29:47 – Do We Overcomplicate the Carbon Conversation?
31:14 – Lessons from Toronto: The 100 Macnab High-Rise Retrofit
32:38 – Drawing the Line: When to Demolish an Existing Fabric
37:28 – Forcing Council’s Hand with Legal NCC Clauses
39:34 – Is Passive House Actually a Premium-Priced Product?
41:11 – Breaking Down the True Cost of Australian Site Labour
44:46 – Linden’s Fire Loss & Installing His Own INTELLO Membrane
48:26 – Thermal Envelope vs. High-End Cabinetry
53:03 – The Intensity Slump on Modern Australian Building Sites
55:26 – Overheads, Insurance Hikes, and Free Market Economics
57:41 – The 3-Story Walk-Up: How Codes Limit Small Footprint Living
58:21 – Why Banks Hate Small Homes and Force Massive Floorplates
01:01:45 – Macroeconomics, Inflation, and Building for the Top 10%
01:08:37 – MEGT Mindful Moment: Harnessing the Un-Jaded Apprentice Mindset
01:11:16 – Connect with Linden Thorley
LINKS:
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Instagram: @sanctumhomes
Website: www.yoursanctum.com.au/
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Website: www.carlandconstructions.com/
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