Excess humidity, damp and mould growth is present in almost half of UK homes, with severe cases affecting over 598,000 properties. A significant majority of these belong to social housing providers for whom this is a long standing problem, and the costs are substantial.
From the moment a tenant complains, the costs start building up; with time and effort spent on fault logging, surveying, reporting, involving contractors, applying fungicide, redecorating and visiting affected properties. In some cases the issue is escalated into a disrepair claim (under Landlord and Tenant; Defective Premises; or Environmental Protection Act). Thereafter, costs can run to tens of thousands (up to £40,000 or more) per property.
Fabric improvement measures such as external wall insulation and double glazing are good for reducing carbon emissions from homes. However, without adequate attention to ventilation there is a risk of increasing condensation as improved airtightness leads to higher levels of indoor humidity. This can also directly affect the tenant’s health.
At first pass, installing adequate ventilation measures may seem like an added expense to any refurbishment contract. However, whole life costs can be significantly more attractive when the reduced expenses of dealing with mould are considered.
One potential approach to this problem is a novel solution from Ventive. They have developed a passive ventilation with heat recovery system (PVHR) that is currently unique in the market. As the name implies, no electricity is required to drive ventilation. The system has the advantage of being completely passive since it uses the pressure difference between the indoor space and the roof (stack effect).
PVHR ducting is normally installed inside the empty space of unused chimneys and starts working immediately after the installation. The product is low maintenance and can be used in new build and retrofit.
In addition, a heat exchanger is embedded into the ducting and as fresh air is drawn in it is pre-warmed before it reaches the room. This means more energy efficiency.
|The PVHR ducting is normally installed inside the empty space of unused chimneys.|
Ventive estimate that for a home that has been “cured” of damp and mould using PVHR, landlords’ lifetime savings can be up to £45,000. The tenant also benefits from around £4,000 by having an energy efficient home and from a healthier life. Plus we all benefit because 15 tonnes of carbon are saved over the lifetime.
But does their system work? Following a two year, 50-property trial in the Royal Borough of Greenwich, Mark Baigent, Assistant Director of Housing at Greenwich, had this to say:
“In Greenwich we had some older street properties with persistent damp and mould problems. We were very impressed with the results of fitting Ventive in these houses. As a result we decided to install the product across a wider number of homes. This programme is helping us fulfil the Council’s commitment to eliminating unhealthy damp conditions, particularly for families with young children.”
Upfront costs of installing PVHR can be reduced by using various financing, mould management and monitoring options. These can start from as little as £25 per month.
Ventive will also offer free stock assessments and Damp & Mould Action Plans for SHIFT Landlords. A limited amount of performance monitoring on selected homes is also available.
 English Housing Survey Headline Report 2014-15