Orientation decides everything
West-facing glass takes the full afternoon. A room that is delightful at eleven can be unusable at five, and no amount of equipment elsewhere in the house fixes it. That room gets its own head and its own control.
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Cooling a post-and-beam house
These houses were built without air conditioning because in 1958 the Peninsula did not obviously need it. Sixty years later people do want it, and the building makes that genuinely difficult. Here is how it is actually done.
Problem one
The ceiling is the finish, and there is nothing above it
In a conventional house the ceiling is a plasterboard lid with a void above it, and that void is where the ductwork lives. In a post-and-beam house the tongue-and-groove decking is the ceiling, the beams are the structure, and the roof sits straight on top. There is no void. There is nowhere to go.
The usual contractor answer is to build a soffit — a boxed-out channel under the ceiling to carry a duct. In an ordinary hallway that is invisible. In a room whose entire character is a continuous plane of wood running out through the glass and becoming the overhang outside, a soffit is vandalism.
So the ducts do not go in the ceiling. Everything else follows from that.
- Wall heads
- A slim indoor unit high on a wall, ideally on a partition rather than a feature wall, and never facing down the length of a glass elevation.
- Ceiling cassettes
- Only where there is a dropped area already — a kitchen, a bathroom, a later addition with a flat plasterboard ceiling.
- Slim ducted units
- Hidden in a closet, a laundry or an existing hallway soffit, feeding two or three nearby rooms with short runs. Excellent for a bedroom wing.
Problem two
The heating is in the concrete
Original heating in these houses is hydronic: warm water circulating through tubing cast into the slab. When it works it is the most comfortable heating there is — silent, even, no draughts, warm underfoot.
The problem is age. The original tubing was copper, it is sixty-plus years old, and it is encased in concrete where it cannot be inspected. Leaks happen, loops block, and the boiler that drives it is usually long past its own replacement date.
Our position on this is simple. If the radiant works, keep it. Add cooling alongside and let each do what it is good at. Nobody should rip out a functioning radiant slab because a contractor would rather sell a furnace.
If it has genuinely failed — several dead loops, unrepairable leaks, a slab that has been cut into twice already — then it is a replacement conversation, and a heat pump doing both heating and cooling is usually where it lands.
- Assessment of what the radiant system is still doing, zone by zone
- An honest view on whether it is worth keeping
- Cooling designed to coexist with it if it stays
Problem three
A wall of glass is a wall of load
The glazing is the reason to own the house and the reason it overheats. Both things are true and the design has to hold both.
Single pane is still common
Plenty of these houses still have original glazing. Replacing it is expensive and contentious among owners who care about the frames, so the system frequently has to be designed around glass that is staying.
The slab helps
Concrete has real thermal mass, which flattens the peaks. It also means the house responds slowly, so scheduling matters more than it does in a light-framed building.
What we will tell you honestly
If your load is dominated by one glass elevation, shading — an exterior screen, a planted overhang, a film — will do more per dollar than upsizing the equipment. We would rather say that and quote a smaller system than sell you the bigger one.
Problem four
Where it goes is the whole job
On a conventional house, placement is a technical question with a handful of acceptable answers. Here it is an architectural one, and there is usually exactly one right answer per room.
- Indoor units
- Above a door head rather than centred on a feature wall. On a partition rather than on the panelling. Out of the sight line from the courtyard, because that view is the point of the house.
- Line sets
- Routed vertically and along existing lines, never diagonally across an elevation. Covered in proper rigid trunking, painted to match the siding — not taped insulation.
- The condenser
- Side yard or rear, on a level pad, never in the courtyard and never facing a bedroom's glass wall from three metres away. Sound rating checked before it is proposed.
- Penetrations
- Through siding, sleeved and sealed, positioned where a future owner would have put them. Never through a beam, never through decking.
The detail nobody photographs
What the outside looks like afterwards
Search for mini-splits in mid-century houses and you will find plenty of tidy interior shots and very few photographs of the elevation. There is a reason for that.
A line set has to get from the indoor unit to the condenser, and on a single-storey house with board siding there is nowhere to hide it. Done carelessly it is a diagonal grey scar across the front of a house people photograph for magazines.
Done properly, it runs vertically in rigid trunking that follows a board line, turns at ninety degrees, and is painted the exact colour of the siding. From the street you have to know it is there.
Questions
About mid-century installations
Do I have to give up the radiant floor to get air conditioning?
No. If the radiant system still works, the sensible approach is usually to leave it doing what it does well — quiet, even background heat — and add a cooling-only or heat-pump system alongside it. The two are not in conflict. Replacing a working radiant slab because a contractor finds it inconvenient is a waste of something good.
Where does the outdoor unit go on a courtyard house?
Usually a side yard or the rear, never the courtyard itself, and never where it faces a bedroom's glass wall across a few metres of paving. Setbacks, the neighbour's windows and sound rating all get checked before we propose a spot, because in these houses an outdoor unit in the wrong place is something you hear every evening.
Can you run ducts in a house with no attic?
Sometimes, in a limited way. A slim ducted indoor unit can be hidden in a closet, a hallway soffit or a laundry, feeding two or three nearby rooms through short runs. It is a good answer for a bedroom wing where nobody wants a head on every wall. What does not work is trying to serve a whole open-plan house that way.
Will this affect the resale value of the house?
Buyers of these houses care intensely about what has been done to them. A neat, well-placed system that respects the architecture is an asset; heads placed carelessly on feature walls, or a line set taped across a front elevation, is something a buyer will ask to have corrected. That is precisely why we agree positions before quoting.
Start with a design visit
We mark the positions, draw the routes and leave you the plan — whether you use us or not.