Architect's Pocket Book / Edition 4

Architect's Pocket Book

Architectural Press

Chapter One

The figures show maximum gust speed likely to be exceeded on average only once in 50 years at 10m above the ground in open country. To convert metres per second to miles per hour multiply by 2.24.

Metric system

The Système International d'Unités (SI), adopted in 1960, is an international and coherent system devised to meet all known needs for measurement in science and technology. It consists of seven base units and the derived units formed as products or quotients of various powers of the base units.

Note that base and derived units, when written as words, are always written with a lower case first letter, even if the word is derived from the name of a person.

Temperature

Kelvin (K) The kelvin belongs to a group of seven SI base units used as a quantitive unit of thermodynamic temperature. It is named after Lord William Thompson Kelvin, a Scottish physicist (1824–1907). In 1848 he suggested a scale of temperature, now called kelvin, in which the zero point is absolute zero – the temperature at which the motions of particles cease and their energies become zero. The units of kelvin and degree celsius temperature intervals are identical (thus 1°C 1K), but the point of absolute zero in celsius is minus 273.15K, thus 0°C = 273.15K.

It is now customary for temperature and temperature intervals to be described in degrees celsius (°C) although colour tem- perature of light sources is measured in degrees kelvin (K).

Celsius (°C) The Celsius scale is a scale of temperature on which water freezes at 0° and boils at 100° under stand- ard conditions. It was devised by Anders Celsius, a Swedish astronomer (1701–44). He originally designated zero as the boiling point of water and 100° as freezing point. The scale was later reversed.

Centigrade A temperature scale using the freezing point of water as zero and the boiling point of water as 100°. The scale is now officially called celsius (see above) to avoid confusion in Europe where the word can mean a measure of plane angle and equals 1/10000 part of a right angle.

Fahrenheit (°F) A scale of temperature still used in the USA which gives the freezing point of water as 32° and boiling point as 212°. Named after Gabriel Daniel Fahrenheit, a Prussian physicist (1686–1736) who invented the mercurial barometer. The Fahrenheit scale is related to the Celsius scale by the following relationships:

temperature °F = (temperature °C x 1.8) + 32 temperature °C = (temperature °F - 32) / 1.8

Nine regular solids

Various types of polyhedra have exercised the minds of mathematicians throughout the ages, including Euclid, whose great work The Elements was intended not so much as a geometry text book but as an introduction to the five regular solids known to the ancient world. This work starts with the equilateral triangle and ends with the construction of the icosahedron.

The five so-called Platonic solids form the first and simplest group of polyhedra. They have regular faces, all of which touch one another, and the lines which make up any of the vertices form a regular polygon.

Further variations of the regular polyhedra, unknown in ancient times, are the Kepler-Poinsot star polyhedra. In all four cases the vertex figures spring from pentagrams. These polyhedra can be formed from the regular dodecahedron and icosahedron.

Kepler (1571–1630) found the two stellated dodecahedra, and Poinsot (1777–1859) discovered the great dodecahedra and the great icosahedron.

Golden section

The golden section or golden mean is an irrational proportion probably known to the ancient Greeks and thought to be divine by Renaissance theorists. It is defined as a line cut in such a way that the smaller section is to the greater as the greater is to the whole, thus:

AC : CB CB : AB

The ratio of the two lengths is called ITLφITL Φ.

Φ = [square root of 5] + 1/2 = 1.61803 ...

For approximate purposes it is 1 : 1.6 or 5 : 8. Φ is the ratio of line lengths in any pentagram.

The golden rectangle is one in which Φ is the ratio of one side to the other.

This is implicated in the mathematics of growth as demonstrated in the Fibonacci series 0, 1, 1, 2, 3, 5, 8, 13, 21, 34 ... where each number is the sum of the preceding two. This ratio of successive numbers increasingly approaches that of the golden rectangle.

The Fibonacci spiral is a curve that increases constantly in size without changing its basic shape. This is demonstrated by using squares increasing in the Fibonacci scale, i.e. 1, 2, 3, 5, from the diagram of which can be seen three nearly golden rectangles.

Leonardo Fibonacci (c.1170–1230) was an Italian mathematician who introduced arabic numerals to Christian Europe. He travelled extensively, particularly in North Africa where he learnt the decimal system and the use of zero. He published this system in Europe but mathematicians were slow to adopt it.

Le Corbusier used the Fibonacci series in his system of proportion 'Le Modulor'.

To draw a golden rectangle:

Draw a square ABCD. Halve the base line at E. From this point draw a line to corner C and with radius EC drop an arc to find point F.

The golden rectangle is AFGD as also is BFGC.

The angle between the diagonal and the long side of a golden rectangle is approximately 31.45°.

Paper sizes

International paper sizes

The basis of the international series is a rectangle having an area of one square metre (A0), the sides of which are in the proportion of 1:

•  2. This is the proportion of the side and diagonal of any square. All the A series are of this proportion, enabling them to be doubled or halved and remain in the same proportion, which is useful for photographic enlargement or reduction. A0 is twice A1 which is twice A2 and so on. Where larger sizes than A0 are needed the A is preceded by a figure, thus 4A is four times A0.

The B series are sizes intermediate between any two A sizes. This series is used mostly for posters and charts. The C series are envelopes to suit the A sizes.

DL or long sizes are obtained by dividing the A and B series into three, four or eight equal parts parallel to the shorter side so that the proportion of 1: 2 is not maintained. In practice, the long sizes should be produced from the A series only.

The dimensions of these series are of the trimmed or finished size.

CAD

Most drawings are now produced on computers enabling instant transfer of information between architects, clients and consultants. There are many computer-aided design (CAD) systems available and the most commonly used programs are AutoCAD, AutoCAD LT, Microstation and Vectorworks, depending on the scale and complexity of projects. Drawings should be constructed in layers organizing the project into different building elements, locations or materials.

Most architectural CAD software can also be used for 3D modelling, which can be useful in terms of design development and communication of ideas. These functions are often complemented by external applications such as Sketch Up, Cinema 4D, 3DS Studio Max and Artlantis, with further graphic enhancement provided by using image editing software like Photoshop.

Standard protocols apply for drawing methods and notation and many manufacturers now supply technical information in CAD format for downloading as DWG, DXF or PDF.

Building Information Modelling (BIM) is also rapidly becoming an essential part of the architectural design process. BIM involves constructing an accurate 3D computer model of the proposed building, which allows elevations, sections and 3D visuals to be extracted from the model rather than drawn, allowing options to be explored more accurately. These systems use parametric objects such as walls, floors, roofs, doors and windows to represent the building design. They also allow information such as quantities, costs or 'u' values to be assigned, allowing the user to interrogate different design options more efficiently.

CAD drawings in this book have been drawn using Vectorworks 2009.

Perspective drawing – method of setting up

1 Draw the plan to a scale and set it at the angle at which it is to be viewed.

2 Establish the position of the Observer on plan, preferably so that the building falls within a 30° cone. Any wider angled cone will produce a distorted perspective. The centreline of this cone is the line of sight.

3 Draw a horizontal line through the plan. This is called the picture plane, which is set at 90° to the line of sight. The further the picture plane is from the Observer, the larger the drawing will be.

4 Draw two lines parallel to the visible sides of the building – from the Observer to the picture plane – to determine the vanishing points (VP). As this building is orthogonal, these lines are at right angles to one another.

5 Draw the horizon where the perspective drawing will be. Draw vertical lines from the picture plane VPs to establish the VPs on the horizon.

6 Draw lines from the Observer to the three lower corners of the plan, cutting the picture plane.

7 Where these lines cut the picture plane at A, B and C, draw vertical lines up to find the three visible corners of the building.

8 Draw a vertical line from one of the two points where the picture plane cuts the plan to establish a vertical scale line. Mark this line to the same scale as the plan to determine the bottom and top edges of the building relative to the horizon. The horizon should be at about 1.6m for normal eye level.

9 Connect these marks to the appropriate vanishing points to complete the outline of the building.

The classifications

• CI/SfB is the classification system most widely used by architectural specifiers. The system has been in operation for more than 30 years and is the industry standard.

• Uniclass is a UK classification system for structuring product literature and project information, incorporating both Common Arrangement of Work Sections (CAWS) and EPIC.

• EPIC is a European-wide classification system and should be included especially if technical literature is to be used on a pan-European basis.

CI/SfB Construction index

CI/SfB is a library system used by the building industry and is suitable for the smallest or largest office.

CI = Construction Index SfB = Samarbetskommitten för Byggnadsfrägor – a Swedish system of the late 1940s.

CI/SfB notation has four divisions:

Table 0 = Physical environment Table 1 = Elements Tables 2 and 3 = Constructions and Materials Table 4 = Activities and Requirements

The current CI/SfB edition was issued in 1976 and is still widely used. It was reviewed and the Uniclass system was developed as a result of this.

Uniclass

Uniclass (Unified Classification for the Construction Industry) was developed following a review of CI/SfB for the Construction Project Information Committee (CPIC) and the DoE Construction Sponsorship Directorate. The project was led by consultants from the National Building Specification (NBS) and is based on principles set out by the International Standards Organisation (ISO). The Construction Products Table is based on the work of Electronic Product Information Co-operation (EPIC).

It was designed for organizing information in libraries and projects, but can also be used for structuring files in databases. It is a faceted system which allows tables to be used independently or in combination with each other. It can be integrated with other information systems such as the Common Arrangement of Works Sections (CAWS), Civil Engineering Standard Method of Measurement (CESMM3) and the Building Cost Information Service (BCIS) Standard Form of Cost Analysis.

Uniclass consists of 15 tables:

A Form of information B Subject disciplines BLDBLD Management D Facilities E Construction entities F Spaces G Elements for buildings H Elements for civil engineering works J Work sections for buildings K Work sections for civil engineering works L Construction products M Construction aids N Properties and characteristics P Materials Q Universal Decimal Classification

Source: RIBA Publishing

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Excerpted from Architect's Pocket Book by Charlotte Baden-Powell Copyright © 2011 by Elsevier Ltd.. Excerpted by permission of Architectural Press. All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.
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