The importance of a good orientation- Sun path studies

“It was one of those March days when the sun shines hot and the wind blows cold: when it is summer in the light, and winter in the shade.”
― Charles Dickens, Great Expectations

 

An Eco-House in Wadebrige, North Cornwall

We were asked by a local builder [a quality one, of course] to design an Eco house for his own family, for a north facing site in Wadebridge, Cornwall. Being on the North Coast we get this often. The client was in a hurry [we get that often, too!], but willing to spend a lot of time with us in the studio, getting thoroughly involved with the design himself. His willingness to explore options allowed us to push the potential for useful solar gain, resulting in a wooden ‘pergola’-like structure on the front of the building that allows the low winter sun in, through the sunroom in to the living space, sinking heat into the thermal mass of the Sunroom which warms the house through day into night. In summer, this wooden structure protects the sun-room from over-heating from the high sun.

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Timber Structure low energy house in Wadebridge, Cornwall.

The design strategy used below is already in operation in our Eco House in Egloshayle a mile away, with three years of monitoring, and average annual space-heating bills of £31 a year. Proper orientation of a new home allows the homeowner to take advantage of a powerful source of lower utility costs: passive solar energy. Orienting a building to accept the sun’s warmth in winter while avoiding excessive solar heat in summer is nothing new. Ancient Greek and Roman houses were oriented and constructed with seasonal solar exposure in mind. Certain realities that influence orientation of buildings never change. The sun rises in the east and sets in the west and midday sunlight is at a low angle in winter and a high angle in summer. Given those basic facts, much can be done to position a home so the daily and seasonal movements of the sun work to your advantage to increase indoor comfort while reducing heating and cooling expenses.

 

 

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Ground floor plan

Shading and ventilation from solar gain in the summer time

 

In the summer time, the sun in Cornwall gets a bit overwhelming. This is a concept we have come up with that accepts a large amount of daylight but not direct midday sun, shading to promote a cool atmosphere in the height of summer. Not only this but the sun room has wide-opening velux windows that allow a good amount of ventilation as they are located in the ceiling which is an ideal location for them regarding convection currents [‘The Stack Effect’]. The result is a house that is warm [ but not too warm] all year round, and has a wonderfully stable humidity of around 50 to 55 per cent.

 

Solar gain during colder seasons.

 

 

In the winter the days are colder and the nights even more so, like a green house the sunroom heats up during the day, and also heats internal walls and floors with high thermal mass. This heat stored in the walls and floor is then dissipated throughout the night keeping an even climate throughout the night. Another alternative to use the sunroom to heat up the living space is to open the glazed doors / windows when the sunroom is to an adequate temperature for direct intake fo the warm air into the living rooms.

 

We look forward to the building being completed and monitoring it in use.

To learn more about our projects have a look on our website.

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