The Lighthouse seeks to address the challenges of future climate change and summer overheating.

The Lighthouse is testing examples of‘ thermal heavyweight’ room ceiling surfaces within a lightweight structural system.

Two different surfaces are demonstrated:

• BASF PCM (Phase Change Material) plasterboard
• Dense cement fibre board

These surfaces help absorb daytime heat and then give it up to cooler night time purge ventilation.

TYPE 1 - 2 storey + mezzanine

Phase Change Material absorb room heat by changing from solid to liquid within microscopic capsules embedded within board. This process is then reversed when the room is cooled with night air.

Room temperature modifying influence of Phase Change Material (Year 2000 climate)

Building services are integrated with Smart Metering and monitoring that records energy consumption and enables occupants to identify if any wastage is occurring, helping to promote more environmentally aware lifestyles.

TYPE 1 - 2 storey + mezzanine

Technical Design

Inherent to the design of the Lighthouse is the response to the predicted increase in temperature due to climate change.

This is achieved through a combination of design techniques and systems.

Selective Thermal Mass

Phase changing material in the ceilings absorbs the room heat by changing from solid to liquid within microscopic capsules embedded in the board. This process is reversed when the room is cooled with the night air, working with the passive system of the windcatcher.

Passive Ventilation

Located on the roof, above the central void over the staircase, the windcatcher provides passive cooling and ventilation. When open this catches the cold air forcing it down into the heart of the houses, living space and the ground floor sleeping accommodation, dispersing the hot air, allowing it to escape.

The windcatcher also brings daylight deep into the plan of the house and provides the ground floor sleeping accommodation with secure night time ventilation.

Solar Gain & Shading

At Level 6 there is a mandatory heat loss parameter which demands high U-values for the building fabric - 0.8 W/m²K for the windows and 0.11W/m²K for the walls. As a result the ratio of glazing to wall in the Lighthouse is 18% as opposed to 25-30% in traditional houses. This drove our decision to locate the living space on to the first floor enabling us to maximise daylight and volume, with a top-lit double height living space.

Shading to the west elevation is provided by retractable shutters restricting direct sunlight, minimising heat gain in the summer. These can be folded away when not required to shade the space from evening sun. Future temperatures in the UK may reach those similar to southern Europe, however, our sun angle will remain low; we still need to maximise sun and daylight midseason and winter. The passive design of the house must balance the technical considerations with the occupants’ expectations who are more accustomed to light and airy living.