A masonry heater is not a product you drop into a living room. It is a half-tonne to two-tonne piece of functional masonry that asks the house around it to accommodate it. This is what that accommodation looks like.
The foundation
Every kit includes foundation drawings specifying footprint, depth, and reinforcement schedule for the model you picked. Most installations want a reinforced concrete pad poured below the frost line, or else tied directly into a monolithic basement slab. Expect 12 to 18 inches of concrete below finish floor, reinforced with 10M or 15M rebar on a 12-inch grid.
The chimney
A masonry heater wants a chimney of the right diameter, right height, and right insulation class. Cold chimneys do not draw. Oversized chimneys cool the flue gasses too quickly and condense tar. The kit ships with a schedule of acceptable diameters and minimum height for the model; most home kits want an 8-inch insulated flue with 18–24 feet of run above the heater.
If you are building new, we recommend a dedicated masonry chimney rising inside the thermal envelope, not the exterior wall. If you are retrofitting, we will help you evaluate whether your existing chimney can host a heater.
The mason
Any competent mason can assemble a Kintsugi kit. What matters is that they have done rigid-mass fireboxes before, or have read the manual end-to-end twice. The kit is numbered. The drawings are complete. The work is patient, not acrobatic. A Whistler is a day of work. A Rome is three.
Timing
Order in summer. Install in early fall. That leaves enough time for the mortar to cure through at least a week of mild firing before you demand a full winter charge from the heater.
Permits
Residential masonry heaters are recognized under NFPA 211 and most Canadian provincial codes. We provide stamped engineering drawings on request for inspector submissions.
Send your floor plan and we will tell you, honestly, whether a masonry heater fits.