The material below is derived from Brooks Breeden, LARCH

Typical Apartment Building

In this unit we will study the design for a small apartment building and the impact that slope has on the design and the number of units in the building.
The image below shows a typical back to back arrangement of units on two floors.  The plan below shows 4 units per floor.  A central stair separates pairs of units and gives access to the upper floor.

   Click thumbnails for a detailed view

The north and south elevations, shown on the left above, are identical.  The east and west elevations are, too.  Each dwelling units shares one wall with another unit.  The plumbing for both units are in this wall for most economical construction.  This typical eight unit building has many alternate arrangements when it is introduced onto a sloping site.
The plan below shows an identical footprint, but notice that there are three floors of units on the north side of the building.  Multi-family structures three stories normally require an elevator.  But this can be avoided on the right site.

These elevation views, below, show a nine foot step between the first and second floor.  Notice that the north elevation is the three story facade, but the South Elevation shows only a two story facade.  Therefore, tenants of third floor units would enter the south facade and walk up only one flight of stairs to reach their dwellings.  but this could be a slope from the south corners of the building to the windows of the northern units.  Notice that in this scheme the entrance to the lowest units is on the north.

For your next exam be able to draw a ten unit apartment building that incorporates a nine foot elevation change.
 

Alternate Grade Change Location

Generally, less earth work is required if the long dimension of buildings are oriented parallel to the contour lines.  However, this is not always possible.  In the scheme above the buildings are place perpendicular to the contours.
 

Eleven Unit Building with Nine Foot Grade Change
Draw a plan and section illustrating an eleven dwelling unit apartment building that incorporates a nine foot elevation change.  Include any required retaining walls or grade changes against the building.
 

Finish Floor Elevations


Notice in the plan view that the street slopes down from north toward the south.  However, units directly across the street from each other have the same finish floor elevation.  There is at least a two foot elevation change from the finish floor to the bottom of the curb.  This change in elevation accommodates an 18" crawl space under the building.  A concrete slab on grade eliminates the need for a crawl space.
 

Section
When the elevation between the FFE and the top of curb is 1.5 feet, a ramp at 7.5% (meeting ADA standards) is possible.  At the section line illustrated above the slope from the curb to the building is over 12%.  Steps are necessary unless a ramp parallel to the building is constructed.  Also note that the 6" step from the FFE to the stoop would not be permitted according to ADA.
 

Maximum Elevation Change

The image below show the maximum change in elevation change between the FFE and the street, if a 20' setback is assumed.

 
 
Increasing the drop in elevation across the street limited.  A sheet flow across a road as shown below is unusual.  Normally streets are crowned.
 

 

Building Foundations
 

 

Extending Foundations for Basements
 
 
 
 
 
 

 
 

In the green circle you can see that the slab and footing on fill has settled while the section of basement resting on undisturbed soil has not.  This produces a crack in the basement slab.  If it is severe enough, the building can collapse.