Passivhaus
Holgate
Agathē builds to the certified Passivhaus standard in Holgate — combining building science and architectural craft on the hinterland acreages that define the Central Coast's prestige.
Agathē builds to the certified Passivhaus standard in Holgate — combining building science and architectural craft on the hinterland acreages that define the Central Coast's prestige.
A certified Passivhaus is measured, not promised. An airtight, highly insulated envelope with continuous filtered fresh air keeps the whole home within a few degrees year-round — without leaning on air conditioning. The result is a home that is quiet, free of draughts and condensation, dramatically cheaper to run, and independently certified to perform exactly as designed.
Holgate's rolling hinterland has long been where the Central Coast builds its most substantial homes — acreage blocks, long driveways, homes designed rather than picked from a catalogue. Sites here reward ambition and punish shortcuts: bushland edges bring bushfire construction requirements, valley air holds humidity, and big floor plans multiply every weakness in a conventional envelope. Passivhaus answers all three at once. Sealed, well-detailed construction satisfies much of what BAL compliance asks for; heat-recovery ventilation keeps indoor air fresh and dry year-round — filtered, on smoke days; and the envelope-first approach means a large family home that costs a fraction of the usual amount to keep comfortable. We bring a Certified Passivhaus Tradesperson and a structured pre-construction process to Holgate builds, so design, budget and performance are resolved before the first trade arrives.
Builder-led delivery of custom homes and Passivhaus builds, managed end to end.
Start the right way with our PAC-certified process — aligning design, budget and timeline before you build.
We work alongside your architect from the first sketch, so Passivhaus performance is designed in, not bolted on.
Scandinavian-inspired homes and cabins built to a healthy, high-performance standard.
Partial to full-scale renovations that transform your existing spaces into healthy, beautiful family living environments.
From design to delivery, we manage every detail for a smooth, on-time, on-budget build.
Yes. AGATHĒ builds architectural custom homes and Passivhaus projects across the Central Coast, including Holgate. Our team includes a Certified Passivhaus Tradesperson, we are members of the Australian Passivhaus Association, and every project starts with our structured pre-construction process so design, budget and performance targets are resolved before construction begins.
A Bushfire Attack Level rating sets the construction requirements for a home on bush fire prone land — the NSW Rural Fire Service explains how ratings are assessed under AS 3959. The higher the rating, the more the build must resist ember attack, radiant heat and flame contact.
Here is the useful overlap: much of what BAL construction demands — sealed junctions, ember-resistant detailing, robust glazing — is what Passivhaus construction does as a matter of course. A well-detailed airtight envelope is one of the best defences against ember entry, so building to Passivhaus standard on bushland acreage is less of a leap than most people expect.
In a conventional home you largely cannot — smoke follows air, and a leaky envelope lets both in. Renew magazine's testing of homes during smoke events found airtight, mechanically ventilated buildings held dramatically cleaner indoor air than leaky ones.
A Passivhaus is sealed against uncontrolled air movement, and every litre of incoming air passes through the ventilation system's filters. On bad air days the home keeps breathing — filtered — while the smoke stays outside.
Yes — if the air only enters where you want it to. In a leaky home, dust and pollen ride in through every gap, which is why surfaces need constant wiping in bushland suburbs like Holgate.
A Passivhaus supplies all of its fresh air through filters, continuously, and the airtight envelope stops the uncontrolled entry paths. For hay fever and asthma households the difference is immediate: measurably cleaner indoor air, all year, without thinking about it.
Because every square metre of leaky, under-insulated fabric is a running cost. Large homes multiply the problem — more glazing losing heat, more roof gaining it, more volume to condition — and the Australian Government's energy.gov.au guidance is blunt that envelope upgrades beat bigger systems.
Passivhaus flips the economics: the envelope does the work, so a large home needs only a fraction of the heating and cooling energy of a conventional one — and holds its comfort even during a blackout.
Yes — any window, any time. The difference is that a Passivhaus does not depend on open windows to stay fresh. The heat-recovery ventilation system supplies filtered fresh air around the clock, so the home stays comfortable and healthy even when it is sealed against a southerly, a heatwave or a week of rain.
It depends on the design, the site and the performance target, which is why we resolve cost early rather than guessing. Our pre-construction process starts with an early feasibility estimate against your concept plans, so you know whether the project is viable before committing to full documentation.
Running costs then work in your favour: a certified Passivhaus needs a fraction of the heating and cooling energy of a conventional home.
Often, yes — the certification pathway for existing buildings is called EnerPHit, and it is genuinely demanding work: airtightness, insulation and ventilation all have to be re-engineered together. Not every home is a candidate, and we will tell you honestly if yours is not.
Many renovations land on a middle path: applying Passivhaus principles and components where they deliver the most benefit, without pursuing full certification.
Whether you are at the early thinking stage or ready to move, we are happy to have an honest conversation. No obligation. We will tell you if we are not the right fit.