You’ve probably heard people refer to drawings for a house as a “set of plans”. Actually, a “plan” is only one type of architectural drawing. Other types of drawings used for design and construction are called elevations, sections and details. These various drawings show different views of a house, or parts of a house.
Plan drawings show horizontal relationships as viewed from above. If you removed the roof from your house and looked straight down, you would see what is called a “Floor Plan” of your house. A Floor Plan shows the layout of your house as projected onto a two-dimensional horizontal plane. Walls, doors, windows, fixtures and cabinetwork are located and dimensioned. For each level in a house separate plans are drawn called the Basement Plan, First Floor Plan, and Second Floor Plan.
There are various kinds of plans. A “Site Plan” shows the house in relation to the land. Topography, streets, driveway, property lines, patio, walkways and underground services are indicated. A “Foundation Plan” details the concrete footings, foundation walls and columns. A “Roof Plan” shows the shape of the roof as seen from above with the ridges, valleys and slopes.
A “Blow-up Plan” is a large scale drawing of a small area to show the arrangement in greater detail. Kitchens and bathrooms are critical areas which should be drawn in blow-up form. Appliances, cabinets and plumbing fixtures can then be laid out in detail to make sure everything will fit during construction.
A “Reflected Ceiling Plan” shows the ceiling design and locates objects on the ceiling, such as light fixtures, mechanical items and architectural features. A Reflected Ceiling Plan shows what you would see if the floor of your house was a mirror and the ceiling was reflected onto the floor.
Plan drawings do not show the height of objects in space above or below the floor line. This type of information is given on drawings called “Elevations” and “Sections”. Elevations show the exterior walls as viewed from the outside and are named by the direction in which they face, such as North, South, East or West Elevation. Elevations show the relationship of objects in the vertical plane, including heights of floors above grade, window shapes, roof lines, and architectural design of the cladding materials. For interior work, Elevations are used to show the design of interior walls or cabinetwork.
If you cut your house vertically in two, and looked inside, you would see what architects call a “Section”. A Section drawing does not mean that only a section of the house is shown, but rather it’s a view of what would be seen along an imaginary cut line through the house. Sections show the vertical relationship of the walls, floors and roofs. An “Exterior Wall Section” is a blow-up drawing which shows the wall construction in detail. It locates and dimensions the siding, sheathing, insulation, vapor barrier and gypsum board.
Detail drawings are always in blow-up form and may be in plan, elevation or section view. Details show the assembly of critical components, such as the connection of the floor structure to the foundation wall, or the roof truss to the exterior wall. Detail drawings are essential for good construction and leave no doubt in the builder’s mind as to how the designer requires the materials to be assembled.
Plans, elevations and sections are two-dimensional scaled drawings which show true measurements required for construction, but not the way something is actually seen in three dimensions. Perspective drawings, which are often used by architects to sell their ideas to clients, show a more realistic three dimensional view of a completed house, but are not drawn to scale and cannot be used for construction.
When selecting a house plan, or having it custom designed, make sure your set of drawings includes more than just “plans”. Elevations, sections and details should also be included. Remember, a house is a three dimensional object, and plans only show the horizontal information. You need the vertical information as well.
A SET OF PLANS – CHECKLIST
When purchasing house plans, or having a house custom designed, ensure your set of plans is complete. If your requirements are well detailed on the construction drawings, contractors’ prices will be more accurate, approvals from municipal authorities will be easier and guesswork during construction will be eliminated. The following drawings are recommended:
1. Site Plan
2. Foundation Plan
3. Structural Plan
4. Floor Plans for each level in the house
5. Roof Plan
6. Elevations of each exterior building face
7. Overall Sections of the house
8. Detailed Exterior Wall Section, showing foundation, floor and roof connections
9. Blow-up plans of the Kitchen and Bathrooms
10. Window details
11. Chimney details
12. Interior details, e.g. fireplace, built-in cabinets, stairs
13. Exterior details, e.g. patios, decks, walkways, steps
14. Details of mechanical and electrical items
