Four metres wide
A house on a very narrow block of land typically shares walls on the side boundaries with neighbouring houses. Houses joined together in this way are called terrace houses and they can often be found in inner city areas where land is in high demand. A four meter wide house will only just have enough room for a hallway to pass beside a reasonably sized bedroom, so this is the minimum comfortable width for single story houses. Narrower designs are possible but they require creative thinking by a clever architect.
Long narrow houses that fill the full width of the available land cannot have windows on either side, so other natural lighting methods are required. Light wells can be very effective at bringing the sun's rays into rooms in the middle portion of the house, in this design a light well brings sunlight and breezes into the bathroom and bedroom two. Skylights are another excellent way to bring in natural light, the kitchen uses a skylight to ensure a well illuminated working area.
Five metres wide
A five metre wide terrace house is narrow but there is ample space for a wide hallway beside a generously sized bedroom. There is even enough width for the living area at the rear of the house to be made narrower allowing for a side passage part-way along the house. Windows can be added to this external wall to bring natural light deeper into the mid-portion of the house. These windows mean no skylights are required in any room.
Six metres wide
At six metres wide, there is enough room to allow a side passage on one side of the house allowing backyard access. This means terrace houses in this configuration can come in sets of two with one adjoining wall between each pair, this is sometimes called a duplex. The side passage also allows for plenty of natural light and cross-ventilation through external windows.
Seven metres wide
At seven metres wide a house will have enough width for a central hallway flanked by bedrooms on either side. This configuration is very space efficient because the hallway becomes half the size. This house shares side boundary walls with its neighbours across the full front facade so a side passage beside the rear living area brings natural light from external windows into the dining room and bathroom. The kitchen requires a skylight because it is too far from a window.
Eight metres wide
At eight metres of land width there is enough space to allow backyard access via a side passage. Windows placed along this external wall bring lots of natural light inside. Windows on two sides of bedroom one and the rear living space capture breezes and provide cross-ventilation.
Nine metres wide
At nine metres of land width a house can discard all shared walls and comfortably 'detatch' from neighboring buildings to be completely surrounded by open space. This allows for windows on all sides of the house to bring natural light and cross-ventilation. The kitchen skylight can be replaced by an external window. As we continue to increase the land size from nine metres there is no need to alter the house design.