The original modest goal was a screen porch. The problems were many:
!) The rear of the house faced southwest, was completely unshaded. and the roofline, combined with the custom-height doors into the family room precluded a classic shed-roof design. The local climate also meant that a classic screen porch would only be pleasant about six days a year.
2) The owners (retired) wanted as close as possible to zero-maintenance.
3) Although the addition would clearly extend an existing deck, the owners wanted to preserve as much daylight into the pre-existing basement as possible.
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After several iterations, the final design uses high-efficiency casement windows (triple glazed, argone filled, with built-in micro blinds and roll-screens) to mimic a screen porch on the few days when the temperature and humidity are comfortable. The lighting is via cove troughs constructed from crown moulding with two lighting circuts, one for bright T5 flourescent fixtures and one circuit for “mood” lighting xenon fixtures.
Winter warmpth is provided by a vent-free gas log fireplace, summer air conditioning comes from an LG “ArtCool” split unit heat pump.
The wooden deck was replaced by an aluminum deck with custom fabricated aluminum steps (both from FSC). As a final detail, the new room was built over its own partial basement which opens onto what is now a breezeway between it and the old basement (thus still allowing light in through the existing windows). Local covenants preclude free-standing out-buidings, so the new basement provides a “shed” for storage of lawnmower, pressure washer, tiller, and similar equipment.
While awaiting delivery of the deck components, the owners decided to go ahead and finish the pre-existing basement as well. This required re-framing the basement stairway, turning what had been a landing into a winder. This gained an additional foot of space at the botom of the steps. The area behind the stairs became an office, the area in front of them became a sitting and sewing room. All basement lighting is high-efficiency LEDs.