Managing a cold, damp house
Authors: Gray, John
ABSTRACT: The climate in New Zealand is mostly cool and humid. Houses in New Zealand are
generally constructed of timber, naturally ventilated, un-insulated if built prior to 1978 and frequently
under-heated. These circumstances result in widespread problems of discomfort and sickness. It has
been estimated that one third of New Zealand houses have mould inside (Howden-Chapman 2002).
Recent medical research has shown links between respiratory illness and cold, damp, overcrowded
houses (egg. Baker et al 2000). Damp and cold are serious problems in New Zealand housing.
The prompt for the study reported in this paper was a colleague’s remark that such problems are
caused “not by the house itself, but the way people use it”. The author was able to test this proposition
firsthand after moving into a small un-insulated house. This limited study showed that whilst it was
possible to achieve tolerably warm and dry conditions through the actions of occupants and ‘correct’
use of ventilation and other hygrothermal variables, some of the actions required were counter-intuitive
and most needed high levels of commitment and knowledge. The study suggests that the solution to
the cold, damp house problem lies more in its design than in educating or regulating the occupants.