The usability of control interfaces in low-carbon housing

Abstract

For the same type of house, energy and water use can vary by up to 14 times between different households in low-carbon housing. This article assesses the usability of key human control interfaces in two contrasting case studies of low-carbon housing, using building performance evaluation and a usability matrix tool. It situates the discussion within socio-technical theories of habit, practice, capabilities and emergent properties in products which facilitate easy, rewarding and energy-efficient learning. Key findings reveal poor design features and occupant lack of understanding including specific aspects of centralised mechanical heating and ventilation systems. Lessons learnt and recommendations are highlighted for design guidance and policy consideration. These include a more user-centred approach to design and testing of products, and key areas of focus in relation to delivering low-carbon homes that are more controllable and therefore more comfortable.

Keywords:

• controls
• heating
• housing
• low carbon
• usability
• ventilation

Acknowledgements

An earlier version of this paper was presented at the 7^th Windsor Conference: The changing context of comfort in an unpredictable world, in Spring 2012.

The authors gratefully acknowledge the funding provided for research informing this study by the Technology Strategy Board through its Building Performance Evaluation Programme, as well as the generous time given by the developers and occupants involved in these case studies.

Notes

Factory settings for the MVHR unit use 13W in trickle mode and 28W in boost mode.

In theory to raise the temperature of the 250-L tank by 10C would need around 3kWh by running the immersion heater for an hour costing 45 pence or wood pellet boiler for 1 hour costing 20 pence. This could typically add up to a £45 difference for topping up over the summer months between the two modes.