To ensure New Zealand homes are fit for purpose, they must have adequate insulation for their location. The requirements vary for different parts of the country, more insulation is needed for houses in colder climates.
One way the level of insulation in any building material is measured or rated is in terms of its thermal resistance, or R-Value. Thermal mass is another important factor in ensuring your home stays warm and dry. Thermal mass is the ability to absorb and store heat energy, meaning homes built with materials with high thermal mass require less energy to heat, cool and ventilate the home.
Solid timber homes have higher thermal mass than conventional timber framed homes. Traditionally, brick and concrete were thought to outperform solid timber for insulation and passive solar heating properties, but studies conducted at Lincoln University in 2007 have shown solid wood to provide up to 2.5 times the thermal mass of concrete per kilo.
Unlike concrete or plasterboard, timber also has the ability to “breathe”, absorbing moisture and regulating temperature making your home more comfortable and more energy efficient. Superior thermal mass also means solid timber homes, such as Lockwood, have lower R-Value requirements than conventional construction.
New Zealand is divided into three climate zones with minimum R-values for each zone based on different construction types. This illustration shows how the exterior wall of a Lockwood home exceeds the required R-Value for all zones.
To achieve these high standards, Lockwood uses Polyisocyanurate insulation tightly sandwiched between solid timber.
Polyiso has excellent thermal performance and boasts one of the highest R values per cm of thickness for any insulation material. It is also CFC and HCFC free, making it environmentally friendly. With the addition of foil facings which act as water and vapour barriers, Polyiso is moisture resistant and won’t shrink or drop throughout its lifetime.
Polyiso does not drip or burn when exposed to fire and will combust at a much later stage than other materials making it a safe choice for homeowners.
If you would like more information, talk to your local contractor or download the brochures below