Kenthurst

Yes. AGATHĒ builds architectural custom homes and Passivhaus projects across the Hills District, including Kenthurst. 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 Kenthurst.

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.