1. Stairs, Windows, Doors, and Roofs

2. Stairs
They are subject to detailed requirements under Building Regulations Approved Document K
in respect of pitch, width, headroom, guarding, landings and treads.
All stairs are required to have protection to prevent people falling from height.
This can be provided by traditional timber balustrading and handrails. ex: balustrades

3. Stairs
Most stairs are generally constructed in timber, steel or concrete, although there are some fantastic glass stairs around. See our page on glass stairs for some good examples.
Spiral stairs are useful when you have restricted space, but can be complicated to set out. Small spiral and spacesaver stairs and ladders are useful for loft conversions.

5. Stringer: the long, diagonal supports that run the entire length of the stairs.
The supports are blocked, cut or notched to accept the individual treads and risers. 
There are usually two stringers, one on each side and occasionally a third in the middle.
Tread: is the flat surface that is stepped on; the width of the tread is equivalent to the run. 
Riser: is the vertical component; the height of the riser is equivalent to the rise. 
Stairs without risers are called "open" stairs.

6. Stairs

7. The maximum height of the riser (or rise that a person needs to step up to the next stair) is 8 to 8-1/4 inches.
The riser's height should not vary more than 1/2 inch between the shortest and tallest risers.
The minimum width of the tread (or run) on which a person places their foot is 8 1/4 to 9 inches.  
If a stair is more than 44 inches wide, a handrail is required on both sides.

8. Stairs Tread should be level with a maximum deviation of a 2% slope.
To ensure stability, the minimum width at any point of stringer should be 3-1/2 inches.
A vertical clearance of 6 feet 8 inches needs to be maintained between the stair and ceiling at all points.
The stairwell must be a minimum of 36 inches wide.

9. Landings
Most fire codes do not allow stairs to rise more than 12 feet without providing a landing.
The length of the landing should be at least equal to the width of the stair tread.
Balustrade
According to the 1996 COBE code, the openings between balusters is to be no greater than 4 inches.  Smaller holes reduce injuries to young children.
The balustrade is topped by a handrail 30 to 38 inches above the top of the stringer; the handrail's grip size is between 1¼ to 2 inches. 
If the handrail is mounted on a wall, a space of at least 1½ inches must be left between the edge of the handrail and the wall.

10. Example of Stairs in Homes:

11. Doors Situation: internal/external Opening: inward/outward
Types: single/double doors/folding/sliding/stable
Performance: fire rated/smoke seal
Material: timber/aluminium/steel/uPVC
Construction: ledge and braced/panelled/solid/veneered
Finish: painted/stained/lacquered/self finish
Glazing: fully glazed/half glazed/solid also clear/frosted
Frame: doorset or loose assembled
Other: weatherstripped/water bar/letterbox/catflap

12. Doors For examples of Doors and Windows:

13. Windows Double or single hung windows Sliding windows
Opens virtically
Sliding windows
Opens horizontally
Casement or rollout windows
Hinged on sides and opens outward

14. Windows Awning or hopper windows Louvered windows
Hinged on top and opens outward
Usually found in basements
Louvered windows
Several strips of glass that are tilted open to allow ventilation
The glass is maneuvered with a rollout type handle or a lever

15. Windows
Bay
Box bay
Casement
Circle Bay
Label Mold

16. Windows
Ribbon Windows
Oriel
Paired windows
Hood Mold
Palladian

17. Roofs
Bonnet:
Cross gabled: often used for Tudors and Cape Cods

18. Roofs Front gabled: Used for Cape Cods and Colonials
Gambrel: Either front- or side-faced; used in Dutch Colonials

19. Roofs Hipped: Used in 1 and 2- stories and four square bungalows
Mansard: Often found in French colonial and Ranch styles

20. Roofs
Pavilion-hipped: Featured in Cape Cod, Colonial, and Ranch styles
Side-gabled:
Salt Box: Featured in two-story colonials; common in the eastern United States