Wood Heater Replacement

Heidelberg, Victoria

Install: October 2015

Client: Seth Keen

Project Goals

Replacement of an existing wood heater with a more efficient Nectre Wood Heater.


The client recently purchased a 1966 brick veneer house that had no insulation but did have an old freestanding cast iron stove that needed replacing. The old stove, a semi-combustion type was better in its day than then available pot belly stoves and certainly more efficient than an open fire (that typically loses more than 90% of its heat up the chimney). However the old stove looked rather tired and dated and in fact after many years’ use was dilapidated.

A Nectre Mk 1 on legs was chosen as the replacement heater. The Nectre Mk 1 is designed to heat open plan areas up to 185m2 (20 Squares) with an average maximum output of 19kW and with an efficiency rating of up to 73%. Particulate emissions are well inside the Australian Standards at a low 0.95g/kg. This Nectre heater meets the 2019 Standards.

Consideration was given to trying to retain parts of the existing flue but given the way it was installed it was decided to install a completely new flue.

The high ceiling was also noted and ceiling fans were recommended to push the heat back down into the room and into other parts of the house.


With the heating sorted the next step was to insulate the roof. 

Basically the rules are: (1) the more insulation the better (within the space available); (2) there are two types of insulation - bulk and reflective; (3) the best result is combination of the two types; (4) apart from the reflective capabilities, it's the air spaces between the materials (and within the bulk material) that does the insulating; (5) the whole area needs to be well insulated - a small gap will lead to considerable unwanted heat gain/loss; (6) use a safe, healthy, non-combustible, pest resistant insulation that won't move around or deteriorate over time.
For Seth we recommended poly batts (Greenstuff) and a layer of reflective sarking to deter the hot summer heat.