Drying room - Scotland

Drying washing indoors can produce large amounts of water vapour that needs to be removed before it can damage the building fabric or generate mould growth that can be a risk to the health of occupants.

From 1963 to 1986 the building regulations included a requirement for the provision of drying facilities. This was removed in response to increased ownership of specialised appliances and the vandalism of common drying areas in blocks of flats.

The current Scottish Technical Standards, require, where reasonably practicable, an accessible outdoor space for drying laundry of at least 1.7 m of clothes line, and a designated internal space of at least 1 m3, allowing 1.7 m of clothes line.

The re-introduction of space to allow washing to be dried other than by a tumble drier was intended to encourage the use of more sustainable methods and reduce carbon dioxide emissions.

The designated space may be either:

• Capable of allowing a wall mounted appliance which may, for example be fixed over a bath, or
• Capable of allowing a ceiling-mounted pulley arrangement, or
• A floor space in the dwelling on which to set out a clothes horse.

Normally a utility room or bathroom is used and mechanical extract is the usual method of removing moisture. Where a space other than a utility room or bathroom is designated, that space should be provided with either:

• Mechanical extraction capable of at least 15 l/s intermittent operation. The fan should be connected through a humidistat set to activate when the relative humidity is between 50 and 65%, or
• A passive stack ventilation system.

However, in 2011, the ‘Design Guide: Healthy Low Energy Home Laundering’, published by the Mackintosh School of Architecture, found that drying laundry in the home posed a health risk to people prone to conditions such as asthma and hay fever.

The report pointed out that 1.7m of clothes line was an inadequate length, and highlighted the fact that the indoor space is not required to be an enclosed dedicated space – a drying room. This means there can be migration of moisture to the rest of the home.

Surveys conducted by the researchers illustrated that residents used convenient drying cupboards when they were provided in a property. However, it was found that drying cupboards had become redundant in many cases, with the removal of a means of extracting air. The report stated that, with appropriate guidance, such spaces could be ‘reactivated’ in existing homes, as well as be designed into new housing.

The researchers recommended that an independently heated and ventilated drying room or cupboard could be located within a bathroom, or other room or circulation space, such as a landing. They recommended the provision of a space capable of accommodating a typical washing load with a minimum net volume of 1.75 m3.

The following dimensional options were provided:

• 1.75 m3 cupboard: 2.3 m high x 0.9 m wide x 0.85 m deep.
• Defined space within a larger utility room: 2.1 m long x 1.5 m deep x 2.3 m high.
• Double-tier vertical hanging space within tighter utility volume: For example, 1.75 m long x 1.5 m deep x 2.3 m high.

The report recommended that a drying room/cupboard should be connected to a house’s central heating system, and ideally, the drying room should have its own heat source capable of being independently operated from the primary heating system, to avoid residents having to turn on the whole heating system to dry laundry.

It also recommended that the internal linings and finishes of dedicated drying spaces be of a suitably hygroscopic (moisture absorbing) nature, such as untreated timber or clayboard.

[edit] Related articles on Designing Buildings Wiki

• Cupboards.
• Humidistat.
• Humidity.
• Mud room.
• Scottish building services certification schemes.
• Scottish building standards.
• Scottish planning policy.
• Stack effect.
• Utility room definition.
• Ventilation.

[edit] External resources

• Home Laundry Study - Design report