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M1
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Traditional Cavity Wall and Strip Foundation
Raft Foundations and Timber Frame Construction

P5 - Principles of Superstructure

Criteria

explain the principles of superstructure design

 

"A Superstructure is the building's shell, it enables the building to be water tight. The superstructure includes all the walls, roofs, windows and doors. It sits on top of the substructure (Foundations)."

 

You should be able to explain what affects the choice of design, for example a traditional pitched slate roof could not span the distances required for warehouse.

 

The superstructure is the part of the building that is above ground or, supported by the substructure of foundations.

The main principles of a superstructure are to be:

  1. Stable
  2. Weather Proof
  3. Comfortable
  4. Secure
  5. Attractive
  6. Safe

 

Stable

This is achieved by various means, but one of the main principles is that the external envelope of the building needs to be sealed from weather on all sides whilst still allowing the building to breath

 

The main strength of the building generally comes from the external walls, but as the building get bigger it will need more structural walls as internal walls. In this picture we can see the main supporting parts of a concrete superstructure. This will be made weatherproof by adding cladding, windows and doors.

 

Materials such as steel and concrete allow us to build taller and wider building, with large open areas on the inside of the building.

 

Discussion Point - Why is it more popular to have open plan living now than 50 years ago, how has building technology influenced this?

 

Weather Proof

 

Roofs need to both protect from rain and snow, as well as keep heat in the building, a pitched roof lets the rain run off, while using overlapping tiles allows for movement in the roof with heat expansion and vapor to escape. Gaps under eaves should be sealed with facia boards and soffits, the overhang of a roof will protect the walls from rain to a certain extent, whilst guttering and downpipes take storm water safely away from a building so as not to cause localised flooding.

 

Wall openings such as windows and doors allow air to flow around the building when required, these are generally set back into the walls. Falls on external window sills allow water to flow away from the window.

 

 

Discussion Point - Why should a flat roof never be perfectly level?

 

 

Comfortable

To be comfortable a building should let in a certain amount of natural daylight, this is achieved by having windows located in the correct positions and using skylights or roof lanterns. South facing is the best option for natural light but is not always possible, in cities the surrounding buildings should be taken into account as the may leave buildings in permanent shade.

 

Thermal comfort is achieved by having a heating system such as radiators, underfloor heating or air conditioning units. Thermal insulation should be used in external roofs, walls and under floors to achive a suitable U-value. Windows should be fitted with ventalation gaps to allow movement of air. Airconditioning whilst more expensive to run may be more appropriate in commercial buildings as they are often only used in the day and often need to be used to bring the tempreture of a building down.

 

Sound proofing is best achived in large apartments by heavy dense materials such as concrete which absorb sound, whilst in traditional and timber frame construction an insulation such as foam will offer more sound proofing than sheeps wool or fibre glass.

 

Discussion Point - Why would you not use suspended timber flooring in an apartment block?

 

When specifying materials for the building consideration should be given to sources of noise such as, busy roads and railways, air traffic and the proximity of neighbours.

 

Discussion Point - What recomendations would you make when designing a row of terrace housing with a pitched roof?

 

 

Secure

A building should keep it's occupants and possesions secure from theft and damage, this is achieved in housing by having a locable door and windows that are built out of suitable materials such as timber or plastic.

 

Buildings such as shops and banks will need a higher level of security due to the nature of their contents, whislt a prison will need to make sure the occupants can't escape.

 

Discussion Point - Where should smoke alarms be placed in a house?

 

Attractive

Looks are also important to a building, by failing to make the structure attractive the designer may not be able to sell the building and an un-attractive building may have a negative impact on the residents, workers or people who use the immediate vicinity. Poor design has also been linked to crime rates by some people and urban redevelopment can be used to improve a run down area.

 

 

The inside of a building such as an office of factory should also be considered, poor design may not inspire people to work hard.

 

Discussion Point - Use Google Street View to find an attractive and not so attractive building in the local area, explain what is right or wrong with each building.

 

 

Safe

The safety of a building is predominantly covered by the building regulations and all buildings should be checked by a building inpscpector as they are made.

 

Fire resistance is achieved by choice of materials, such as treated timbers and plasterboards that resist the spread of fire. In commercial buildings fire escapes and sprinkler systems may be required.

 

Staircase in commercial buildings should have breaks at appropriate intervals to prevent people falling a long distance and doors should have a window to avoid collisions with someone the other side of the door.

 

Hygene should also be considered, hospitals need to have easily cleanable surfaces, toilets should not join onto to main living areas or food preperation areas.

 

Discussion Point - Why do stairwell lights have a switch at the top and base of the stairwell?