urban form definition in urban planning

LEITURA DA IMAGEM URBANA

URBAN FORMDEFINITION

LUZ VALENTE-PEREIRAEDIÇÃO DE AUTOR

SINOPSISSINOPSIS

IN URBAN PLANNING

ÍNDICEAbstract

INTRODUTION

Chapter 1 - PHYSICAL ELEMENTS OF URBAN MORPHOLOGY

Urban Form Elements ��8Landscape/Soil ��8Outdoors Space ��8Buildings ��9

Landscape/Soil Morphology ��10Landscape/Soil and Urban Settlement Morphology ��10Landscape/Soil Morphology and Urban Standards ��12

Outdoors Space Morphology ��13Circulation Space ��14

Circulation Space Morphology ��14Circulation Space and Urban Settlement Morphology ��15Circulation Space Morphology and Urban Standards ��15

Outdoors Meeting Space��17Outdoors Meeting Space Morphology ��17Outdoors Meeting Space and Urban Settlement Morphology ��18Outdoors Meeting Space Morphology and Urban Standards ��19

Building Morphology ��20Building and Urban Settlement Morphology ��21Building Morphology and Urban Standards ��21

Chapter 2 - THE URBAN FORM AND OTHER ELEMENTS OF THE URBAN SYSTEM

Outdoors Spaces ��24Definition Form of Outdoors Spaces in Planning ��24Outdoors Spaces and other Elements of the Urban System ��25

Buildings ��27Definition of the Buildings in Planning ��28The Buildings and Other Elements of the Urban System ��28

Abstract

URBAN FORM DEFINITION IN URBAN PLANNING

It is necessary to explore the scale of urban planning with the subject matter of architecture, which does not stop at building designs� Neither does it become urban just because architects design blocks of buildings and the outdoors space between�The urban space must be a pre-existence with respect to building projects, which shall successively interpret and carry it out� Knowledge and means at our disposal must also be determined in terms of physical planning as to define, establish, and/or issue standards for an urban space�The creation of this architectural object - urban space - requires a reformulation of understanding methods and transmitting the outdoors space’s form independently from the building project, which shall interpret the latter and carry it out�Those subjects send us to different kinds of problems:

• To clarify the town concepts of designers and citizens;• To know the relation between the town concept and its physical expression;• To define the formal expression of urban planning;• To discuss the morphology characteristics that translate the town concept to be

implemented;• To adapt professional practices to new architectonic responsibilities�

In this paper we develop an approach to the relation between the town concept and its physical expression, as well as the form characteristics that will be established in urban plans�

INTRODUTION

The urban space production has led to new urban areas being built from scratch, particularly in terms of wider building areas� These are added into the space in every intervention,

either connected or separated by roads, including a collective urban space, which is planned/designed as another space to be accomplished within this project, just like a house, a museum or a garden�

This urban development process may lead to a careful formalisation of urban space in the building area, creating a vacuum in the borders between buildings abandoning continuous and subsequent spaces during multiple interventions, having been designed by the different designers.Being the urban space’s characteristics and the latter’s general design established in each architectural project, urban space becomes engrained in itself, that is, it takes on an identical design value as the space within the buildings, it starts and ends on the project, it is surrounded by this, it expresses its formal and conceptual logic, it echoes its customers, just like in the building� The architectonic expression of this building project’s author seizes the urban space, which starts out as a more permanent and collective pre-existence and changes into a group of personal expression spaces of everyday life�When considering that the aim of the architectural project - not architecture as a subject - transcends the formal interpretation of the buildings and encompasses at the time the urban definition of that area, plus its implications in collective experience and interventions on that urban territory throughout time, this shall reduce the town into the urban area in the design phase, thus rendering physical planning devoid of any concept, among others - where this shall only be asserted on a political and social and economic level with no spatial expression beyond the indication of areas for use, density, and height, as well as a road system establishing a relation between the different areas, with well-known consequences for the town concept within the zones -, and architecture becomes impaired with no possibility of including the most profound and solid base of its formal creation on an urban scale, not just for the building or building area�On a planning level, the town is thought of and designed as a circulation system separating or connecting micro-urban islands (language itself translates this - they are the housing developments�� ); on an architectonic level, we dream of a town and design those developments as if they were great buildings, each translating the significant yet depleting urban consistency that is unique to a project which does not arise from the interaction of several players but rather a single author in confrontation with themselves on every corner�These observations only prove the need to explore urban planning with the subject matter of architecture, which exceeds building designs� Neither is it urban just because architects design building areas�The urban space design must be a pre-existence with respect to building projects, which shall successively interpret and carry it out�

The terms of this pre-existence must be established as well as its form and expression� Knowledge and means at our disposal must also be determined in terms of physical planning as to define by drawing and/or issuing standards (which ‘drawings’? Which ‘standards’?) for an urban space� These means should provide designers with information on the intended town concept and should be sufficiently general as to be interpreted by different architectural projects.This issue concerns a new architectural dimension, which fits into the planning stage and its solution requires that the urban space be an architectural object rather than the result of a project juxtaposition regarding buildings designed as monuments within a space that, although it shapes the town, only complements the buildings, devoid of collective meaning, not continuing beyond that established�The creation of this architectural object - urban space - requires a reformulation of understanding methods and transmitting the outdoors space’s form, which was caught in its urban dimension moving beyond the simple inclusion of outdoors spaces within the architecture project�The physical expression of the relation between places within the town, which influence a dynamic diversity, should be addressed with an expression that is implied in the decided town concept and deprived of all the elements that comprise the personal expression of each place� Each place would therefore be readable and workable on two architectonic levels: like ‘one of the places in town’ connected to it by means of a group of morphologic characteristics expressing their cultural position, which may be recognised as a significant partof a whole that has been decided upon on a physical planning level as an urban architecture issue, as well as ‘that place’, with its own expression established in terms of an architectural project or projects�The need to clarify and inform this new architectural object to be worked on during the planning stage - much praised yet conceptual and methodologically unknown in architecture - requires an analysis of the different levels expressed by the architecture and reorganisation of professional practices�Those subjects send us to different kinds of problems, which are as follows:

• To clarify the town concepts of designers and citizens, thus enabling a broader discussion, which would be essential for collective understanding and decision regarding the environment where we intend to live�

• To know the relation between the town concept and its physical expression, between concepts and practised forms by urban designers, and between concepts and understood forms by the citizens, so that spatial operators will become explicit, that is, to identify design decisions expressing urban organisational intentions to given town concepts� Besides being essential to implement the architectural projects - seeking forms that spatialise the urban and architectonic concepts in a given place, which have been decided upon during space production -, this knowledge also clarifies the spatial aspects to be established by physical planning when deciding the key aspects

of urban development, responding to the requirements of urban transformations, and changing everyday use�

• To define the formal expression of urban planning, that is, to clarify planning capacity in binding urban morphology and subsequently determining the degrees of freedom for architecture projects in the decision of urban space�

• To discuss the morphologic characteristics that translate the town concept to be implemented in a given time and the changes to production method and space consumption intended by society as to come closer to the town that has been collectively decided upon as being desirable and possible� In general terms, this formal characterisation would originate what we would call ‘urban style’� Let us add the following:

– The difficulty to form an ‘urban style’ is profoundly cultural given the characteristics of a consumer society - ‘fashion’ multiplicity and turnover, fascination with novelty instead of the new, with movement instead of change, with the object’s representation instead of its real possibility to be used in everyday lives, and particularly the precedence of economic over social and cultural with all the decision, process, and construction consequences�

– The introduction to an ‘architectonic discussion’ in the planning carried out in every produced plan, followed by confrontation, analysis, broadcast, and discussion of experiments - in terms of the general population, using municipal bodies and the media, and in terms of experts in classes, seminars, meetings�� and speciality magazines - would lead to the creation of a collective urban culture, and successive clarification of the town’s contents and ‘style’, thus enabling a standard from a professional point of view, which would be an organised transmission of knowledge as a result of the analysed and discussed confrontation of practices, hence overcoming the establishment of standards for the simple political and economic needs of the ruling class - specified in the legislation - and the influence of usually imported physical models by means of achievements of successful professionals, which have been published in magazines, which have often been of exceptional quality - non-specified�

• To adapt professional practices to new architectonic responsibilities, which imply the following, among others:

– To establish the subject matter for the architect’s intervention in urban planning as such (1);

– To establish the order of architectural projects, which shall achieve the respective urban plans, not through groups of buildings for a certain area but rather city routes which were established due to the fact that they comprise a set with a

(1) We tell apart the subject matter that is architecture from the architect - licensed individual in Architecture - applying and developing their knowledge in all different planning areas - management, building, research, ��; here we refer the specific architectural contents - the translation of concepts/programmes/meanings for inhab-iting in habitable forms rather than multiple interventions by a licensed technician�

readable urban meaning - design a road, an intersection, a square��;– To institutionalise urban planning as a continuous activity throughout time,

which is included in local decision and management structures;– To develop research, criticism, and broadcast activities in order to make it

possible for analysing, comparing, and discussing multiple plans, projects, and ventures throughout the country, as well as the methods used in their design and implementation;

– To create, develop, and interconnect participation structures for the population, professionals, and media as to improve knowledge regarding content and methods for designing the urban environment�

Next we will outline a few proposals as to open discussion on the formal elements defining the relation between town concepts and their physical expression, as well as the established and discussed characteristics in urban plans, which should be the starting point for the multiple architectural projects to be implemented in the planned town(1)�

(1) This publication corresponds to the revised text of - Luz Valente-Pereira, ‘Definição da Forma Urbana no Planeamento Físico’, Memória 570, Lisbon, LNEC, 1982�

Chapter 1 - PHYSICAL ELEMENTS OF URBAN MORPHOLOGY

Urban Form Elements

The form of the town is established in the relation between the outdoors space and buildings, which exist in a given landscape/soil� These are then the elements to be

analysed by themselves, between themselves, and in their relation with other urban elements�

Landscape/Soil

The influence of landscape/soil in morphologic terms mainly concerns location, topography, sun and wind exposure, and soil and subsoil quality and aptitude and

landscape composition�

Such data influence the following:

• Great distribution of buildings and green areas throughout built and open spaces;• The infrastructure outline laying particular stress on the road infrastructure;• The general definition of building typologies, their forms of association, and

distribution throughout the landscape/soil;• The three-dimensional urban composition;• The general reading and readability system for the space arising from the topographic

configuration and landscape characteristics�

Outdoors Space

Considering its morphologic definition, the outdoors space shall be analysed based on two categories in terms of use, which have serious implications on its form, therefore we

must consider:

• Circulation space - the circulation scheme for vehicles and pedestrians, analysed in terms of spatial formal expression as well as its access relations, that is, the roads’ circulation hierarchy and access to activities, type of access network connecting the roads, their relation with the buildings and outdoors meeting spaces�

• Outdoors meeting space - urban being spaces - analysed based on dimensional categories related with the type of private or public permanence as well as how they are linked with the buildings and the spatial circulation system� The analysed categories in these outdoors meeting spaces are those of paved and non-paved (green areas) spaces, as well as public and private spaces�

Buildings

The buildings are characterised according to their typological definition and forms of association regarding their relation with outdoors spaces and the way buildings access

the outdoors space�

Landscape/Soil Morphology

Landscape analysis within an urban intervention must be carried out by an expert� During the Integrated Plan of Almada/Monte da Caparica(1) the importance of the following was

highlighted as to define landscape/soil morphology:

• Topography, outlining the location and form of valleys, hills and platforms, water lines, and detention basins and influencing micro-climates�

• Soil characteristics in terms of aptitude/occupancy, indicating the areas for agricultural, forest, and construction use�

• Property subdivision and type of construction allotment.• Pre-existing built elements, such as walls, slopes, wells, mills��, buildings and their

morphologic definition�• Pre-existing road structure.• Remarkable landscape elements, such as valley lines, panoramic and crest routes,

remarkable emerging points, landscape areas, geographical features, and water lines�

Landscape/Soil and Urban Settlement Morphology

This factor’s influence on the settlement’s morphology depends on the town concept and landscape soil characteristics. A place’s natural order is readable and its transformation

by means of urbanisation must provide a new order�

When identifying the transformation mechanism or creating a new order it is important to

(1) In the report by the same author, ‘A Forma Urbana no Planeamento Físico’ Lisbon, LNEC, 1983, this subject is developed and illustrated through the practical results of the analysed theory of the Integrated Plan of Alma-da-Monte da Caparica carried out in the FFH, which took place along with the project and planning team for the mentioned Plan during its design�

know the essential lines for planning the existing landscape and take them into consideration when preparing the plan�Urbanisation disturbs the landscape’s order and its recreation assumes multiple factors besides the landscape ones� However, these are essential for the fundamental aspects in the area’s ecological balance.The safeguarding of cultural values within the landscape is already open for discussion based on the compatibility of said values with the transformation expected in the urbanisation and the fact that the original contents are usually drained with the new conditions�The mentioned cultural values mainly support the landscape’s history, which is the base for its reintegration rather than the decision to preserve pre-existing elements - the quicker and easier way which often disguises the lack of capacity to clarify intentions and forms of expression of present conditions through history itself�The influence of elements defining the morphology of the existing landscape in the urban settlement morphology may be expressed through the following:

• The existence and location of physical barriers, which limit the extension and possible continuous relations between the analysed settlement and surrounding areas, as well as parts of the settlement�

• Area type, extension, and diversity in different topographic, orientation, and soil situations, which delimit the possible distribution:

– Of areas based on construction, cultivation, and forestation�– Of building typologies expressed in groups based on the different characteristics

of areas with construction capacity�– Of cultivation and forestation typologies�

• Type of border established between areas within different slopes, which have an implication on the general infrastructure system with emphasis on the road network and natural drainage issues�

• Subdivision and allotment, base of the decisions to use and express the humanised landscape morphology, either by means of the ownership regime, which has a direct implication on urban management and may maintain important morphologic characteristics, or by experience in adapting the environment to previous uses and social organisations, which explains the decision to transform the landscape�

• Preservation of more significant historical landmarks, which although they have been drained of original contents are still considered important in terms of memory and may redefine themselves in the new context�

• Volumetry definition marked by the indication of general volumes of the buildings or green blocks; profile types and the delimitation of general fronts and axis arising from a reading of the existing landscape, which contribute towards a first image of the settlement’s urban composition containing morphologic definitions�

Landscape/Soil Morphology and Urban Standards

Regarding landscape/soil and in order to bind the plan’s morphology, urban standards for each plan must include:

• Land use capacity for agricultural and forest soil as well as green leisure, sport, and resting areas, establishing protection and development means�

• Conditions and goals for safeguarding natural and built pre-existing elements�• Environmental protection conditions for outdoors spaces and buildings based on

their exposures�• Rules to be considered as to ensure essential aspects for the area’s ecological balance.• Infrastructure landscaping integration through their outlines and general rules of

urban composition - general volumes, profiles, fronts and axis�The establishment of management for green spaces is very important for the plan to be carried out, as well as recommendations regarding species to be used based on the landscape�

Outdoors Space Morphology

As we said, considering its morphologic definition, the outdoors space shall be analysed based on two categories in terms of use, which have serious implications on its form,

therefore we must consider: Circulation space and Outdoors Meeting Space.

Circulation Space

Circulation Space Morphology

The circulation space morphology of a settlement is a specialised area, which must pay attention to the general decisions regarding the following:

• Ground morphology and option to stick to or be independent from the circulation system in terms of its limitations�

• Type and form of the network connecting the settlement or urban area under analysis with the surrounding settlements or areas - network accessing the exterior�

• How inside connections define themselves and the network accessing the exterior within the considered urban space - general distribution network.

• How connections are made inside the urban space - local distribution network.• Type of definition or absence of indications on the roads directly accessing the

buildings - local access network.

• How tissue irrigation is ‘spatialised’ by pedestrians - pedestrian circulation network -, which may coincide with the road circulation network�

• Option for a hierarchy system where networks are clearly different, thus creating circuits with no options out of each hierarchy or a more or less neutral system with partial network overlapping on the roads or versatile network/s.

• Space form characteristics for the different networks - circulation lane profiles, method and rules for using side lanes, method and rules for the vertical components (façades and horizon openings)�

Circulation Space and Urban Settlement MorphologyThe form of circulation spaces is one of the highlights of urban tissue morphology and

essential in defining the town concept given that:

• It lays down constraints to the extension/connection of the area with the surrounding areas defining its autonomy/isolation or the possibilities of being formally and functionally integrated within a wider urban tissue;

• It defines the dimensions and geometry of the building network, either ranking it or not into sub-groups with consequences in terms of independence and formal and functional integration as well as the distribution of building typologies that may adapt to each network area;

• It points towards a relationship between the road network, outdoors meeting spaces and buildings in terms of formal and functional integration and spatial distribution of use or omits it, which indicates how this relationship is viewed;

• It contributes towards activity localisation with repercussions in the usable building typologies;

• It defines the scale of the urban settlement as a whole or in part;• It decides on the existence of a definition for the form of circulation spaces in terms

of planning or only establishes the road scheme�

Circulation Space Morphology and Urban StandardsIn terms of circulation spaces, the pictured or described indication of the following may be

included in the urban standards of the general plan considering project contracts:

• Type of ground morphology integration across roads and/or rules or cases regarding non-operations�

• Road network hierarchies adopted in the plan and described as:– Type of access created by each hierarchy regarding the exterior of each area and

different points within the tissue�

– Type of relation established between the roads belonging to different hierarchies when defining the irrigation network for the whole�

– Profiles for the roads and side lanes corresponding to each hierarchy with the necessary indication for the urban design and outline conditions based on the need of great groups of activities to directly access the roads�

– Indication of the relation to be established between each hierarchy and the immediately close buildings (gap, access delimitation, parking, landscaping��)�

– Minimum and maximum dimensions of the divided network for planting the buildings defined for each hierarchy establishing the degree of tissue accessibility for all types of residents - in wider areas of the settlement or outside the settlement�

• Indication of the types of solutions for single cases introduced in the plan as being very often or comprehending wide areas - such as gradient solutions or slope treatment�

• General indications on the design of aspects deemed important for the formal continuity towards the circulation space - lighting, urban furniture, sidewalk treatment, and types of vegetable species��

Outdoors Meeting Space

Outdoors Meeting Space Morphology

The outdoors meeting space morphology is strictly related to the type of social appropriation of the soil, it reflects the space’s production method, and is delimited by cultural and

functional aspects�

The main factors for the morphologic decision are:

• Importance given to soil occupation by the outdoors meeting spaces in relation to circulation spaces and buildings�

• Values and functions for remaining in the outdoors space, either due to a meeting, social gathering or party, whether it be public or semi-public or private related to the building typology, there will be implications on dimensions, distribution, and hierarchy of the urban tissue�

• Characteristics of the related network within the group of outdoors urban spaces;• Concepts regarding the clarity and intent of formal definition of the outdoors

meeting space regarding it as a regulator for the building outlines, which are formally controlled as objects themselves and may lead to the general characterisation of the space’s form, hence including their vertical components (building façades, fences, walls, staircases, green areas, and slopes��)�

• The scale of the urban settlement in the whole local and national territory�• Concepts regarding that designated as ‘green space’, its dimensions, urban distribution,

and formal treatment�

Outdoors Meeting Space and Urban Settlement Morphology

The outdoors meeting space morphology sets the pace for internal use of the settlement in spatial terms - alternations and continuities between circulation and outdoors meeting

spaces�

The contribution of this network’s form for the urban tissue morphology depends on the importance given during soil occupancy and concern regarding its execution�The outdoors meeting space is not profitable, since its construction and maintenance are considerably expensive� The tendency is then to exhaust urban tissue in circulation spaces and buildings� On the other hand, there is a lot of pressure from the population and concerned technicians as to include these projects multiplying them within the urban tissue and broadening their dimensions�Depending on the conditions for space production, outdoors meeting spaces will be of much or less importance or not at all in determining the settlement’s form� This importance is also related to the established hierarchy between the urban elements during the decision on the general morphology of an urban settlement�Circulation spaces are the first in the decision’s hierarchy for a long time, hence delimiting profoundly the tissue’s morphology�The definition of outdoors meeting space morphology in terms of planning is usually only established for the great green structures, where public meeting paved and non-paved spaces deemed necessary will be indicated near residential areas�Hence the definition of the outdoors meeting space network is then omitted, that is, how they relate with each other, the circulation network, and the buildings in morphologic terms, and how the spaces which do not directly connect with residential areas are developed - central outdoors meeting spaces� This is equivalent to eliminating the contribution of outdoors meeting spaces from the settlement’s formal structure� They may appear during the execution of architectonic groups or as expectant areas, outside the settlement, swallowed by the latter as they grow�The outdoors meeting space morphology is important as an expression of collective urban being that means the full settlement experience, which is the importance, quality, and type of activity, amplitude and diversity of social groups and collective population meetings�

This network also indicates the settlement’s territorial scale�We believe to be of utmost importance viewing this network with an identical attention as that given to circulation spaces so that we may find them a suitable place in the town and highlight their profound urban dimension�

Outdoors Meeting Space Morphology and Urban Standards

The urban standards, either pictured or in the plan’s regulations, should deliberate on the type of network deemed suitable for the outdoors meeting spaces:

• To the urban expression and territorial scale of the analysed settlement establishing the logics of its inter-relations�

• To the use hierarchy defined by type and dimensions (residential, central, metropolitan or national) of the social, meeting, party, and leisure groups within�

• To the preferential situations, as well as morphologic and functional ones regarding the circulation spaces and buildings�

It is also important to define general aspects regarding typical urban design situations related with the aforementioned data and indicate types of pavement, urban furniture, landscape, and other data of the utmost importance for intervention characterisation and hierarchy�As previously mentioned for circulation spaces, aspects to be considered in the vertical components of outdoors meeting spaces should be indicated, which are essential for the general definition of a three-dimensional urban form as well as circulation routes�

Building Morphology

As we have been observing, the decision to nominalise the form of the outdoors space is made on a physical planning level, where the buildings are established as being the

induced element or not, as a consequence of the formal definition of the urban outdoors space, or the inducer which designs and characterises it�

If one believes the buildings to be the inducers of the outdoors space’s form, decisions with a formal impact on planning will simply include the territorial location of activities - either establishing or not typologies that interpret them and the main circulation schemes - and the urban space’s form shall essentially depend on the decisions made in terms of building architecture� This is the prevailing point of view in spite of the attempts to recover the urban space as a substantive space, an architectonic space, a designed space.The space’s production method has led to the design and construction of wider building areas, which become bigger with every intervention and have their own outdoors space�

The uselessness of physical planning has been proven in this urban development in spite of the eventual capacity to locate and programme uses and densities� The form of the settlement’s space is then a result of all the formal initiatives within the multiple architectural projects added�We are then able to conclude that the exterior form of the buildings is either decided upon during the architectural project for the buildings(1) or corresponds to the interpretation/realisation of the already established urban outdoors space’s form on a planning level and is interpreted by designers when drawing building façades for the decided activities by the programmes�Whether giving decision priority to architectural projects or defining the form of urban spaces in planning, the form of the urban buildings refer to an issue that is related to the buildings and which is essentially analysed either starting on the activities to take place, constructive decisions and architectonic concepts of the designers, or decisions made regarding the town concept established in the planning, which includes options on the location of activity type and group forms for the concerned planning�Whatever the case, all quoted aspects must be considered, where only the priority of decision factors will vary along with the moment and agents of the decision, which are decisive for the town’s form�

Building and Urban Settlement Morphology

In our perspective, the definition of urban morphology is established when the outdoors space morphology is defined, where this is a substantive three-dimensional space�

The buildings are the main element in the outdoors space’s vertical component, being subjected to its formal and functional requirements, to the stated town concept, which is linked to the idea of activity integration/succession, including those of the urban being�This is not equivalent to stating that the building environment functions as an urban ‘scenery’ independently of what takes place ‘behind the facades’, although on the other hand, the decision on the urban form implies a profound knowledge of the building typologies and their organised distribution as to solve the formal unit and diversity of the outdoors space and proper location of its uses�

Building Morphology and Urban Standards

The mentioned urban standards for the buildings in a given plan must indicate the building typologies corresponding to different types of activity, group forms, contour, and soil

surface they occupy as well as access typology delimiting the transition between the building

(1) In compliance with densities, indexes, and programmes with a limited formal impact on the structuring aspect of a designed and continuous outdoors space�

interior and outdoors spaces�

Volumetry definitions and facade composition type must be indicated within the standards defining the outdoors space, which are established considering the typological distribution, which denotes the distribution of the use types within the built area�

Chapter 2 - THE URBAN FORM AND OTHER ELEMENTS OF THE URBAN SYSTEM

In order to analyse and assess an urban tissue, after the elements defining the morphology of an urban form have been described, we shall indicate the characteristics of those elements

thus enabling us to formalise them based on different town concepts and establish the relations between those characteristics and other elements within the urban system.

In summary, we believe that the formal characterisation of an urban tissue is based on:• The identification of elements comprising the urban tissue’s form: outdoors spaces

and buildings, both depending on the relations between themselves within the occupancy of a landscape/soil, a pre-existing element with characteristics limiting the development of the former�

• The identification of characteristics describing these elements, which are differently informed as the town concept varies�

• The knowledge of the relation between the characteristics of these form elements and those of the urban system elements - activities, behaviour, and environment (reading and readability)�

Then we shall indicate:

• The mentioned characteristics, which enable a description of the form of outdoors spaces and buildings, since landscape/soil influence in urban form has practically exhausted itself in the previous paragraph� Regarding the project, there are multiple suggested interpretations by this contribution, which are either of the responsibility of designers or are included in the planning decisions for outdoors spaces and buildings;

• The relation between the mentioned formal characteristics and those of other urban system elements, which are decided upon on a planning level and for which formal translations have been sought�

Outdoors Spaces

Definition Form of Outdoors Spaces in Planning

The form of outdoors spaces is established by defining the following in terms of planning:

• Access network, that is, the form of the circulation space network for people and goods, which is directly related with the distribution method and characterises urban circulation as having an impact on other activities� The following characterise the network form:

– Hierarchy degree for the network (without hierarchies, with one, two or three�� circulation hierarchies)�

– Irrigation scheme for the space by the mentioned network (radial, linear, square, ‘spaghetti’��)�

– Characteristics telling each hierarchy apart (type of circulation, relation with activities, and connection method with other hierarchies��)�

• Outdoors meeting space distribution network, spaces for urban public meeting activities, the form of which depends on the following:

– The decision regarding the buildings and circulation spaces (closed, semi-closed, independent��)�

– The spatial relation between the aforementioned spaces (spread across the urban space, directly interconnecting through openings within the buildings or indirectly by crossing circulation spaces, either continuously or forming concentration clusters developed based on previously established urban axes��)�

– The characteristics defining use and symbolism of the different spaces forming the distribution network (importance as a meeting point for the population on the same scale as a settlement or place, as an image guiding the reading of the urban tissue, as a place for collective demonstrations, parties, fairs, national or local symbols��)�

• The formal expression of the architectonic space, that is, the formal expression of the circulation and outdoors meeting spaces, not in terms of the network they establish as a whole, which creates a dynamic relation for all parts, but rather space surrounding the people in every moment, delimited in the horizon and directly related with the architectonic environment it provides, type of social activities, meetings, and/or enabled circulation� The formal decision regarding the outdoors space is related with its position within the network and must consider:

– The scale of the urban settlement (Metropolitan, regional or local)�– Its scale in relation with the settlement itself (central or peripheral)�

– Type of contour geometry of outdoors spaces (regular, irregular or amorphous��)�– Dimension, defined in terms of general characterisation of population group

dimensions related with the scale of the sought environment and settlement�– Relation with the horizon (closed by the buildings or green area, semi-closed,

opening towards far horizons��)�– The composition of the vertical components of the outdoors space, that is, of

the buildings and/or other types of exterior surfaces (green blocks, further away buildings, views of the water��) establishing:

* Type of communication between the interior and exterior (facing blocks, fenestration only enabling lights with visual or direct access to the exterior��);

* Compositional diversity, which might be based on the readability of the activities taking place behind the vertical component (different floors or homogeneity, delimitation of the ground floor; representation system; vertical, horizontal, and other important compositional rules prevail; continuity or differentiation per sector; type of facade line-up, arches, land adjustment��);

* Access type defining the transition between interior and exterior (the delimitation based on their concentration or dispersion; the importance of their readability and hierarchy; importance and type of definition for the delimitation between the public, semi-public, private, and semi-private fields��)�

These element characteristics for the formal definition of outdoors spaces were established due to considering that their variations highlight significant differences in the characterisation of other urban system elements, which should be established on a settlement planning level as to express the designed town concept and ‘style’ and be interpreted by the multiple architectural projects realising them.

Outdoors Spaces and other Elements of the Urban System

Now let us see the relation between the form of outdoors spaces as we described it and other elements of the urban system�

The form of the access network interconnecting circulation spaces:

• It provides a hierarchy of circulation with repercussions in the characteristics accessing the implemented activities or produces a neutral network with established and consolidated hierarchy by the urban practice�

• It defines the rhythm and possibilities for a change of direction.

• It establishes the dimension limits for the implemented buildings with implications on the group forms, building typologies, density and location of activities�

• It indicates rules for guiding travels and subsequently, tissue readability�• It influences the soil occupancy indexes and infrastructure outlines.• It defines the urban tissue development units and has implications on the methods

of renewal and extension of the aforementioned tissue�The form of the distribution network for outdoors meeting spaces:

• It polarises, scatters, and guides the social and meeting activities�• It defines the relation between journey and stay, rhythm, frequency, and continuous

use with interpenetration or separation of population groups and their activities.• It indicates the type of relation established between outdoors meeting spaces and the

buildings, and subsequently all activities therein�• It contributes towards readability of the urban space by defining landmarks or

confuses it by annulling the readability of spaces on the way�• It makes it easier or more difficult to define public, private, and semi-public domains

with implications on appropriation, use, and preservation of the outdoors space (management)�

• It defines the control and safety requirements for the urban space�• It has implications on the diversity or monotony of the urban environment resulting

from the different perspectives, spatial distribution, forms of appropriation, and urban behaviour�

The formal expression of circulation and outdoors meeting spaces:• It points out the type of urban being either staying or circulating, with implications

on the composition and behaviour of population groups, activities carried out, and the surrounding environment in general terms rather than for simple functional relations;

• It indicates the scale of the settlement for the region where it belongs;• It indicates the position in history and prevailing values at the time it took place

(religious, leisure, economic, social, and aesthetic)�• It indicates how readability of type of activities (housing, commerce, leisure...)

taking place in the buildings is viewed from an outsider point of view and publicly valued characteristics�

Buildings

Our view of the outdoors space - a substantive space, three-dimensional, planned object, not only in terms of organisation, but also the characterisation of the form expressing

it - means that many of the general characteristics of the building form shall be defined in terms of planning at the moment the general characteristics are established for the outdoors space’s form�

Now, being important to display this point of view as a means to emphasise the disadvantages of the town design being a result of all the building projects or groups of buildings, which were only located by planning, the fact is that the limitations of this study have led us in the opposite direction - to exhaust the town planning by deciding its outdoors space without apparently considering the contribution or importance of activities and subsequent building typologies in its definition�This paragraph could include the characterisation of the buildings as to provide information on the urban consequences of spatialising activities, which take place inside the buildings and relating them with each other in sequences� This being essential information for making decisions on outdoors space characteristics (1)�The outdoors space definition - as not to become a gratuitous act of creating a scenery - includes acquired knowledge of consequences within the exterior urban space of any type of activity existing (residence, industry, offices, �� ) in the buildings and how they are formally expressed and organised�This information alone enables a decision regarding the convenient sequences for locating activities translating a given urban life concept, which refer to their respective building typologies and identify certain ranges of outdoors space formal characteristics�Knowledge of the building typologies and their group forms is then basic information for planning and making decisions on the form of urban settlements�We have not developed this aspect since we did not carry out this analysis� We have sought to highlight the need to plan an urban space based on its own logic, valuing itself as an architectonic object�What we have stated implies redefining priorities on a design level, which may be summed up as follows:

• Addressing the outdoors space network from the start, not only as a road network, but also as a continuous place for urban activities to be carried out and adapted�

• Locating great activity groups throughout the concerned network rather than in areas of the territory, analysing the effect of content definitions (people acting) and created urban sequences rather than only controlling the physical installation

(1) (1) In the study ‘Modelo de Análise do Sistema Urbano à Escala de Zona Urbana’, L. Valente Pereira, LNEC, 1971, we characterise the urban system and indicate at an early stage the logic for deciding the ‘activity’ element and the method for characterising it considering decision-making on the urban form.

activities capacities�• Discussing and establishing formal characteristics of the outdoors space network as

to enable/favour the sequence of necessary activities and environments for the urban space to become effective based on the decided town concept� This characteristic definition must ensure flexibility, transmission, and discussion of the said concept by designers, politicians, and the general population, who are responsible for its approval and accomplishment�

Definition of the Buildings in Planning

Since we have not developed the study of building typologies and their group forms, we are simply drawing attention to the need to acquire a deep knowledge on the matter

and proceed with its urban reading, that is, considering the requirements regarding the soil surface, contour and volume, established interior/exterior relation from an inhabitable point of view as well as the produced effects on the outdoors space and access conditions�

We are hereby providing some examples of the mentioned characteristics as simple indications:

• Type of contour defining the soil (isolated buildings, bands, groups of bands, open forms - U, T, L, irregular forms and closed forms - regular and irregular blocks��) and surface (soil occupancy areas per typology to be considered)�

• Type of façade surface (compact or divided, horizontal or vertical predominance, low, medium or high; regular or irregular height��)�

• Type of access based on requirements regarding its readability, formal delimitation and appropriation - public, semi-public, semi-private, private - and based on dispersion or concentration regarding the public space - which is related to the definition of how the interior/exterior is accessed�

The Buildings and Other Elements of the Urban System

We are indicating these definition elements because we believe that their variation has an impact on significant variations of other elements of the urban system� Hence:

• Type of contour and surface occupied by the buildings:

– Is related with requirements regarding the organisation of accommodated activities, either among themselves or with the exterior;

– Defines formal features of outdoors spaces and their degree of communication through the buildings, which has implications on use and management of appropriation and preservation;

– Defines soil occupancy indexes�

• Volume influences:

– Activity distribution and inflow characteristics for the outdoors space�– Environmental scale�– Conditions for carrying out the activities in the buildings with an emphasis on

security, access easiness and means, type of contact with urban soil�– Dimensions of the outdoors space to be immediately used in identical healthy

conditions�

• Type of facing of the façades influences:

– The relation between activities inside the buildings and outside�– Urban environment - readability of the activities within the buildings, variety or

repetitiveness, transparency or opacity, scale, texture, graphics, urban character�

• Type of access delimits:– Space definition as public, semi-public, private or semi-private�– Pace of irrigation of the outdoors space by the activities within the buildings�– Accessibility of the buildings with implications on the definition of internal and

external routes and their appropriation and management as well as those of the outdoors space�

urban form definition in urban planning

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