Dry home

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The factsheets, case studies and articles in this section are all about how to achieve a dry home.

A dry home is warm: cold air holds far less moisture than warm air.   In cold temperatures the moisture naturally in the air settles on cold surfaces such as un-insulated walls, ceilings and windows as condensation.  Moisture is also absorbed into fabrics and building   materials. This moisture build-up causes mould and mildew on walls and fabrics, which is not only unsightly, but can trigger allergies. For example, dust mites -  the source of one of the most powerful biological allergens - thrive in damp conditions.

A dry home also gets rid of moisture at its source: by stopping moisture coming into the home and by ventilating to get rid of moisture.   Moisture accumulates in a house from people bathing, showering, cooking, breathing, and watering plants. It also comes into a home from outside. Some appliances, such as unflued gas heaters, clothes dryers, dishwashers and washing machines, also produce excess moisture into the air. The moisture builds up quickly and is worse in modern homes which are built to be almost airtight and have no ventilation.

It takes more energy to heat moisture-laden air than dry air, so reducing moisture inside will also help keep your home warmer.

  • 10-Oct-2018 (Publication )

    Managing mould (PDF 170KB)

    Beacon Pathway and the Home Performance Advisor programme

    Advice to householders on managing mould, based on the latest research and best practice.

  • 03-Jul-2013 (Publication Factsheet/5)

    Heating: Unflued Gas Heaters (PDF 64KB)

    This Beacon factsheet covers why unflued gas heaters are both dangerous and not cost effective to use.

  • 03-Jul-2013 (Publication Factsheet/6)

    Improving Your Rented Home (PDF 73KB)

    This Beacon factsheet covers low cost options to improve your rented home: stopping heat escaping (draught-proofing, DIY double glazing, curtains, solar shutters); getting rid of dampness (under-floor ground cover)l and efficient heating.


  • 03-Jul-2013 (Publication Factsheet/4)

    Healthy Indoor Air (PDF 68KB)

    This Beacon factsheet covers eliminating the sources of moisture in the home, and ventilating to get rid of moisture and indoor pollutants.

  • 03-Jul-2013 (Publication Factsheet/25)

    Improving Your Cold Damp House (PDF 31KB)

    This Beacon factsheet covers steps to address cold and damp, and whole house heating or ventilation systems.

  • 03-Jul-2013 (Publication Factsheet/32)

    Whole House Ventilation Systems (PDF 35KB)

    This Beacon factsheet covers positive pressure or roof cavity ventilation systems, balanced pressure or heat recovery ventilation systems, and what to consider before you buy.

  • 01-Jul-2013 (Publication Case study/19)

    Hot in Summer, Freezing in Winter (PDF 288KB)

    Covers the steps a Gisborne household took to improve the performance of their old villa.

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HSS High Standard of Sustainability® benchmarks for a dry home:


  • 40-70% humidity in living areas during the evening
  • 40-70% humidity in bedrooms overnight

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