Give every room in which people spend time daylight from at least two sides; plan the building in narrow wings so that this is possible.
Rules · Plans · Light · Materials
The zero-energy terrace
Face the homes south behind glazed sunspaces; put workspaces on the north side, in the shadow of the row in front, where even light suits them; cover the roofs with sedum and gardens; and ventilate through wind-driven cowls with heat recovery.
BedZED’s section makes one row serve two needs: the south-facing homes take the sun, and the north-facing offices, which would overheat on the south side, sit in the zone the solar spacing rule would otherwise leave empty. Super-insulated walls, triple glazing and heavy thermal mass reduce heating demand to a small fraction of the ordinary; the cowls turn to face away from the wind, drawing stale air out and fresh air in past a heat exchanger.
Related rules
Shape the space between buildings as carefully as the rooms: make outdoor spaces partly enclosed and convex, like outdoor rooms, rather than leftover gaps around freestanding objects.
On an equator-facing window, make the overhang deep enough to shade the whole window from the high noon sun of summer, and no deeper, so that the low winter sun passes beneath it into the room.
noon sun altitude = 90° − latitude ± 23.44° · overhang D = window height ⁄ tan(summer altitude)
Place heavy materials (concrete, stone, brick, earth) where the winter sun falls on them inside the insulated envelope, so that they absorb heat by day and give it back at night.
Make the envelope so well insulated and airtight, and recover so much heat from the exhaust air, that the building needs almost no active heating.
heating ≤ 15 kWh/m²·a · airtightness n₅₀ ≤ 0.6 h⁻¹ · heat recovery ≥ 75%
Make neighbourhoods compact, pedestrian-friendly and mixed in use, with a clear centre and edge, so that daily needs lie within a short walk: about a quarter of a mile, five minutes, from centre to edge.
centre to edge ≈ ¼ mile ≈ 400 m ≈ 5 minutes on foot
Cite this page Chris Paton, “The zero-energy terrace”, The Textbook of Architecture, https://textbookofarchitecture.com/rule/zed-terrace. Text, drawings and models licensed under CC BY-NC 4.0.