INTEGRATED ENVIRONMENTAL DESIGN OF BUILDINGS

Professor P E. O'Sullivan

The Welsh School of Architecture, University of Wales Institute of Science and Technology

Introduction

Historically, the concept of buildings as a means intarnal envirOnment and known physical optima of protection against the more inimical natural for human comfort and convenience, with elements, predators and the like has gradually economy and efficiency of means; in short, in given way, with social and cultural development, designing an effective filter between man and to increaSingly sophisticated control and his natural environment. On occasions, modification of the natural climate in the environmental effects resulting from decisions interests of more efficient and comfortable about the building itself through the subsequent participation in more and more complex installation of services. Such a concept demands human activities. At any given time the degree a new rationale of collaboration in the design of success has been related to the state of process. The partiCipants, building owner scientific and technological development. The or client, the design and building teams all former has made possible increaSingly accurate contribute toward a common and speciflcation of psychophysical conditions for comprehensive view of long and short term aims. optimum efficiency and comfort, the latter the All share the decision at the inception of a means of achieving them with greater certainty. project to integrate design factors for which Though reJa tions hips between cause and effect they are normally individually responsible. are far from simple, theoretical knowledge has Furthermore, decision making thereafter becomes usually been in advance of applicable a concurrent process in all the disciplines techniques, and fragmentation in the interests involved in a nd not sequential (and, therefore, of deeper speCialised knowledge (as in the logically isolated) as in the n'Jrmal case of medical sciences, for example) has tended to building design. produce isolated techniques for the better achievement of specifications - whether visual (eg the glare indexes of the IES Code) 1 thermal The Environmental 'Era' (eg Webb's work on effective temperature) 2 or aural (eg the Dutch work on the sound It is important to note, yet not generally insulating properties of glass) 3 - to accord recognised, how new the current approach to with the individual criteria emerging from environmental design is, for it can well be specialist studies in depth of each aspect. argued tha t the environmental era began It is only recently that efforts have been 'offiCially' in November 1967, when the made to bring together a number of environmental Institution of Mechanical Engineers held their and building design factors. It is the intention Conference on 'Heating and Ventilating for a of this paper to trace the brief but important Human Environment'. For this reason the history of these efforts in Great Britain and the results, although fully documented are worth effects they have had on building design. summariSing here.

Billington -4 and Crenko 5 in the separate ways, Integrated Design reviewed the work on di scomfort. They indicated that under 'stress' conditions, The concept of integrated design adopted in increasing the air temperature, varying the thi s pap er recognises that the building itself, humidity and rate of air airflow, and increasing its fabric, shape and relation to local the Effective Temperature, could and indeed climatic conditions, its effect on those had been correlated with a fall off in conditions and its internal organisation of space, productivity and Health, and an increase in are no less important than installed services industrial accidents. However, when' stress' in effecting a close relationship between condi tions did not apply, for example, in air

25-2-1 t'emperatures of 20"C or less,comfort Envelope itself, ie, by the properties conditions were assumed to occur. In this of the materials in construction. 'region' no optimum standards had been determined, nor indeed what tolerances exi sted. Further, that it was these first two stages What was true in the Thermal Environment combined, which should act as the course appeared als~ to be true in the Acoustic control on the environment to produce the Environment . (basically) correct internal climate. That mistakes made in (a) and (b) could not be 7 The state of the Art of Heating and Ventilating ,8 rectified in stage (c) which conSisted of the was widely discussed, mainly in terms of 'fine tuning' of the environment so produced, by 'hardware'. The control of the thermal the thermal plant, the lighting etc. environment, however, appeared to be easily 'dismissed' with such statements as .•...... Inherent, in this concept was a numerate based if 'normal' heating and ventilating is unable to probabilistic view of design, which can be cope with the internal conditions, and in some summarised as .... 'you can never be cases this happens, then Air Conditioning can absolutely right, so how wrong do you want and must be provided ..... either by traditional to be?' or by packaged units 9. The implication being that Heating and Ventilating plant sometimes in Stage (a) above was further set on a firm the form of air conditioning, can and will solve 'climatic' basiS by Lamb 11 in his the environmental problems created by the discussion on Heat Islands. building, albeit at a cost. Further, that the key to this problem solution was through Controls Force was added to the argument in Stage (c) and Control Theory. New and better controls, by Eccleston 12 who showed how the wi th increa sed rate s of response, for example, performance of thermal plant was dependent on would- make up for the deficiencies of plant and the building envelope. Finally, Scott 13 buildings. demonstrated that these new ideas, required a new role, that he and other people were already The cost of building services, both as a total beginning to define. and as a percentage was increasing rapidly. The suggestion was that this cost could be offset to some extent by 'standardisation' always Window Function allowing that 'flexibility' was maintained. This concept of Climatic Modification, with So the 'traditional' service arguments were the enphasis on the building as the prime restated as they had been done so clearly for control, was seen by some Architects and many years. The picture which emerged was indeed some Heating and Ventilating Engineers, that of a technology, highly developed but with as a means of establishing a new route through no theoretical base to relate it to 'buildings'. the problem of environmentally uncontrollable buildings and the attendant blame that attached However, at this same Conference where the to them. An analyst s of thi s problem wa s , tradi tional view wa s so powerfully put I the attempted under the heading of 'window beginnings of a new Concept emerged. function' 14.

The Concept of Climatic Modification 10 in Window function may be regarded a s three foid: which the building is considered as a filter to provide planar illumination (the specified between man and hi s environment, a filter level determines the area of gla ss required); to between the meteorological climate on the provide a directional component in the lighting one hand and the required private climate on (which varies with shape and position of the other 'appeared'. This filter was considered windows); and to provide a view out (which may to have three sections. Namely: determine the number, the size, and to some extent the position of windows). A basic a. The conversion of the meteorological environmental deSign deCision is how to allocate climate of the region, to the correct priorities to these three functions, and how to microclimate around the building. combine them in such a way as to achieve a b. The modification of this microclimate specified integrated environment. The by the properties of the Building relationships of window function to the principal

25- 2-2 aspects of the physical environment are dealt brightness sky may be the area of greatest wi th separately and collecti vely below. luminance visible from inside the room, causing serious visual distraction and a serious reduction in visual acuity. If, in addition, the The Visual Environment windows admit direct sunlight, excessive luminous contrasts can result, reducing visual A fixed quantitative stand"lrd for natural acuity still further, and possibly producing lighting has three 'effects' on building design: reflected glare from specular surfaces, and so still greater vi sual di scomfort. a. For a given floor to ceiling height it limi ts room depth (Fig 1) or restricts The distribution of daylight within a sidelit room the buildings to a single storey, unless (Fig 1) is such that the illumination levels close clerestory windows or roof lights are to the windows are very high compared with the used to augment the unidirectional levels at the back of the room, particularly, if it lighting. is more than 4· 8m deep. For example, in an b. It produces designs with a high ratio office with no rooflights and deSigned to give a of external wall area to internal volume. minimum of 2% DF at points most distant from the wi ndow, there could well be a 20% DF near the c. It produces designs with a high window wall. Though the quantity of daylight proportion of glazed to unglazed external reaching the rear of the room is 'adequate' in wall. terms of the recommendations, it appears gloomy by comparison, and artificial light is used for subjective, as apposed to funcational, rea sons. It can be seen, therefore, that in buildings with windows designed for planar illumination, artificial lighting is often used and/or blinds may be drawn 18 to reduce visually uncomfortable luminous contrasts between the sky and room interior or within the room between the working areas near to and distant from the ~or fOoIlitIItllllM ~ ... ,....tIir! 0 FllIItI13i11!Dmwid!ofId &1OIm_ with HllmMl)llJm tti"'IIeigIIt$,the~isfrolnciUtoetiling IJndwaUtI'" With window, to prevent excessive brightness contrasts l'IIIi.IIObstructeci sky - 3aln ttiIiII; _·_·-·-HDOm C4i1ing due to direct sunlight, or simply to augment GIA6l4M IllUS'RlllIIIi MOW OAYU6H'~ REIMINmS CAlI LIMn .... DEPTH 'inadequate' illumination levels. Blinds reduce . 15 sky and sun glare. Artificial lighting improves For example, a 2% Daylight Factor (DF) related the luminance distribution over the room area to the standard overcast CIE sky of 5000 lux and increases planar illumination when necesoory. produces minimum internal illumination of 100 Both are needed where windows are deSigned in lux, but of course sky brightness varies. In the terms of planar illumination only. They do, United Kingdom this variation is such that, however, provide also a directional component, during an average year, 100 lux is achieved or necessary for clear 'f?ual resolution of solid exceeded for 84% of the periods during which or modelled objects and for the offices are occupied (0900-1730) 16. psychological desirable outward view. It would seem, therefore, that since planar illumination Recommended levels of planar illumination have can be artificially augmented, it should no risen progressively with ri~ing standards of longer be paramount, and that the latter living. The IES standards 7 reflect this. functions should be given greater priority in Clearly, if these recommendations are met for window deSign. only about 50% of normal working hours, the point has been reached at which it is impossible to meet them in rooms of economic ceiling Thermal Environment height merely by increasing the area of window. (Many offices built to the 2% DF The application of 'climatic modification' to already have ci11 to ceiling and wall to wall the thermal environment, resulted in the 20 glazing, and any increase in window area would emergence of the idea of a 'Balance Point' necessitate an increase in ceiling height). which may be deSCribed as follows. Furthermore, large areas of glazing produce' sky glare' discomfort under certain conditions of sky It is possible to plot on a graph of axes external luminance, irrespective of orientation 17. High

25-2-3 air temperature v heat input, both the heat losses from a building which increase approximately linearly with decrease in external temperature, and the heat gains to a building which increase with increase in air temperature, but not linearly. An example is given in Fig 2.

OOTBIDE TEMPERATURE "C Figure 3 The idea of 'controllable' building, ie, one which acts not only as a control on the external climate but also as a control on both the total heating/cooling requirement and the time for which that applies had emerged, and what is more, emerged as design based. FigUf':! 2 During the same period further work on the The point where the two curves cross is known external climate, 21,22 defined more clearly as the 'balance point'. At all external air the existence and potential of heat islands, temperatures above the 'balance point' the that is, the increased air temperatures found building is self-sufficient in heat, albeit in in cities, which can be correlated with urban some conditions uncontrollably as the upward density. This work when linked to the new swinging heat gains curve shows. The balance 'probabilistic' view mentioned earlier, point shown is that for a 15m wide, 2% DF produce, and is still prodUCing from theresults building with 1'0% of the external wall glazed of a computer analysis of all the British and balances at 16"C. It, therefore, requires MeteorolOgical Data of Dry Bulb Air Temperatures, heating whenever the external air temperature temperature curves such as Fig" 23 which give falls below this value and conversely it may the probability of any external air temperature require cooling and that of a large order when the occurring at any time. It is this work which external air temperature rises. enabled the theoretical concept of a Balance Point to be put onto a predictive deSign basis. The effects of the various design steps that might be taken to improve this thermal' state' of affairs 100 ...,::,=-:=~: _ \I ___ ~ __ 10 _ ,~ =_=_ ~'l.l~ :10 are shown in Fig 3. For example, the effect of ------t-- --I--rr' - .~ M j" ..., redUCing the U-value 6f the opaque parts of the wall from 0.7 to 0.57 W/mz deg C is quite small: the heat loss curve moves from 1 to 2. Reducing --1---1---+--- "' the area of glass from 70% to 20% reduces the heat loss from 1 to 3 and increases the heat gains / from B to A. In other words, it is possible to draw / a diagram of the effects on the thermal properties of the building, and therefore, on its thermal / performance, of design deci sions concerning, / windows, materials and so on. f--+--+-----tf.C I

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25- 2- 4 concept of climatic modification and the of this through cracks around the edges of the ,,::::endant balance pOint theory have centred a windows - ie, it is not a simple area effect as deal of research interest on the building in the case of solar overheating 23. Unless e,:-,'elope in the last five years (eg 24,25,26,27). windows are sealed (with all this implies in t.lUs work it can be concluded that the better terms of artificial ventilation) and made more

climatic modification characteri stics I the acoustically efficient, there is, once again, the heat losses and hence the easier and the conclusion that window size should be :l:",eaper' it is to control the internal thermal reduced. ~:::~'ironment. Taking window function again in ::::::'s context, the larger the 'proportion' of glass axternal walls the greater will be the effects The Total Environment solar overheating and radiation and/or :c::'lective cooling, producing greater heat losres In 1968 these 'sets' of results began to come

::ro'1gh the fabric by conduction and radiation, together. As a result of 'climatic modification' I ;:eater heat gains due to radiation, larger buildings which were both thermally efficient ::r.::.ilding air temperature swings, greater and comfortable were wanted, and for perhaps :i;fficulties in thermal control, and more the first time designers clearly understood complaints of unsatisfactory thermal environment. how to produce them. There was also a desire :::ese problems, directly related to glass area to design and produce thermal plant, matched to cannot be overcome merely by air conditioning these buildings, which would be economic and : B129,30 or my manipulating the thermal efficient. ;:;roperties of the opaque parts of the building enclosure. As it is not possible (except for very specialised purposes) to design a building in

Ihe case I therefore, for reducing areas of glass the United Kingdom that will require heating all was made and resulted in conclusions such as the time, the dec! sion wa s taken to produce :hose shown in Table 1 27. buildings that required no heating overall, ie, were self- sufficient in heat. However, a

Table 1: Lillit. of glass areas as a percentage of total building balancing at I for example, O"C poses arsa of southfacing facade (no exterDal. screeDing) several problems in practice. For self­ Tharmal. Thenal Thermal sufficiency in heat overall does not necessarily environment environment environaent is uncon- is controll may be con­ mean the right amount of heat at the right time trollabla able with trollable even with current "i th mechani­ in the right areas, since some areas tend to current. standards cal ventila­ standards of of air tion only produce too much heat some too little. air condit- condition- Traditionally the excess heat would be thrown ioll1ng ing away and ne"" heat generated for the heat lightweight a1ngle glazing grsat.er than 60 per cent. 20 per cent starved areas. Could not the excess heat 60 per cent or le8a or lesl produced (which had already been paid for) be ----~~~~~-+--~~~--.-­ construction double gluing ~sat.r than 50 per cent 20per ce~ collected and transferred to parts of the building 50 per cent. or 1e •• or less that need it? The answer was 'yes' as a result heavyweight s1ng1e gluing ..,.eater than 75 per cen 20 per cent of a new idea in air condi tioning I namely, 75 per cent or 1e.. or le •• 'heat recovery'. 33 construction double gluing ~~ater than 65 per cen 40 per cent - 165 per oent or le.. or le .. _.__ ._.. __ .. ____ -' _____ c....._____ L ______The idea is as follows. The heat producing areas (people and light in offices; people, light and machinery in production spaces) have their excess heat removed by a cooling air load. The Acoustic Environment This load is designed to be as stable as possible as a result of the thermal properties The continual increase in external noise levels of the building enclosure. The heat now in the (eg, urban traffic noise) had made urgent the air is then recovered by a heat recovery coil problem of preventing penetration of noise into instead of being thrown away and redi stributed buildings. Recent fieldwork on the sound to other parts of the building. Finally I any insulation characteristics of windows excess heat is thrown away. demonstrates that, of the external noise penetrating a window wall, approximately, 90'l' In fact, if the buildings were thermally comes through the windows, and more than half efficient and the heat loss was low, a large

25- 2-5 proportion of the heat would be continually where the economic break points are, and thrown away during working hours, so that a therefore, what heating and/or cooling further development to enable that heat system should be used is unfortunately of recovered to be stored during the day and then no great help in designing the actual used to preheat the building next morning, system itself. could occur. (v) Furthermore, the balance point tends to lead to over optimistic assumptions of Consequently, the follcming deci sions were how much heat can be recovered, is worth made: for lighting purposes, windows would be recovering, and what can be done with it. designed to produce a directional component For example, it can lead one into of light and view out only; planar illumination designing complex controls to operate would be provided by electric lighting; window basically simple plant, in order to recover area would be reduced to approximately 20% of that extra 2% of heat. the external facade, and the general thermal and acoustic properties of the fabric would be (vi) Integrated Design can lead to the designed to give the best possible combined establishment of a method which can be performance in terms of heat loss, heat gain, described as the 'mesh'. This occurs temperature swing, and human' comfort' . when a set of building performance parameters are first established and These decisions have now been applied to a 'meshed' against a set of 'human' number of building types 34 of which the most parameters to produce the required significant are, the Wallsend Building 35,36 inta-nal environment, and appears to the Eastergate School 37, the Liverpool Daily suffer from two disadvantages. Firstly, Post and Echo Building, 38 the Simon Building, because of the very way that thermal Stockport 39, and the Bentalls Store, plant operate s, it tends to produce regula r Bracknell 40. environmental conditions, and secondly, because the human parameters have been It is important to remember that these based on 'comfort' conditions (established buildings, perhaps, more properly described as by 'lack of complaint' and personal 'controlled experiments', built through the opinion), the results are not as universally process of Integrated DeSign, have only satisfactory as was originally hoped. recently corne into use. So that although these buildings were instrumented in order to record Further as the building parameters were the only the energy balance and the resulting physical ones that were based on actual evidence, the environment, results have to date been scarce evidence, two parallel research programmes must and are only now available for analysis. also be considered: Similarly, the way people use these buildings, (a) As 'comfort' conditions were not defined the 'human end' evaluation, and to ensure that, and appeared to span a wide range of for example, the visual environment has not which no one knew what the tolerances deteriorated as a result of improving thermal and were, the idea of a 'swing' of internal acoustic performance has Just begun. Hence, building temperatures emerged as a means conclUSions drawn from them can only be of reducing plant costs and size, 41 and tentati ve. However, the indications are: attempts to define acceptable Swings (1) The ability of these buildings to produce began. The author's own current research and control the desired internal thermal work leads him to believe there is in fact environment is establi shed. no such thing as 'comfort', but that there are three zones, namely, discomfort; (11) User reaction to the Environments so lack of discomfort; and pleasure. Current produced appears to be favourable (see knowledge enables one to design ~n the 'filmed' evidence). 'lack of discomfort' zone, but there is (iii) Predicted economics of capital and no information, but plenty of opinion, on running costs have been realised. how to de si gn for plea sure. (iv) The balance point concept, although (b) Currently, many research workers have and necessary to the design of a 'controllable' are taking part in a research programme to building, and to explain to the deSign measure the performance of thermai.plant. team how the thermal parameters interact, Yet apart from re-affiring that hot air still

25-2-6 rises, the most important factor discovered to date is that 'non assessibility' appears to be the fundamental cri teria in plant design. The fact is that how heating and/or cooling systems work is not known in anything but the crudest detail. There are too many partial measurements, too many approximations, and too many unmea surable system s. Furthermore, the indications are that systems which are designed to work at optimum efficiency at the design conditions are for the majority of their --_ ...... = .. !.-.. life when design conditions are very seldom met, operating at anything up to 40% inefficiently. Figure 5 This then is the situation that has been reached

.... -'!'<> .... --' ...... _- as the result of the first Research and ::po.... , ...... ' .. _ ...... -

Development Cycle. I '

Current Research

In December 1970 it was concluded that the previous work was 'definitive' enough to encourage further detailed research and application of the principles 14 outlined above. For the feedback results had suggested that there were two ideas that could be developed, for the Designer, namely: Figure 6 (a) Variety reducing constraints - the law of Using these results a series of complete buildings dimini shing returns. of simple rectangular plane form were next (b) 'Positive' degrees of freedom. analysed. The following parameters were varied: width/length ratio; number of storeys; total floor To this end, a range of standard structural area; floor to floor height; heat transfer panels of different combinations of materials in coefficient of roof and floor; window wall ratio. construction was first investigated by computer An analysis showing the effect of these simulation to demonstra te the effect of choice of variables on heat loss I capital, and running materials and differing glass and solid ratios. costs was derived. Fig 7 gives an example of An example of the results, is given in Fig 5, the results. translated into terms of 'heat loss' in Fig 6. From this study a limited number of materials in construction, economic in thermal, acoustic and constructional terms emerged, for example, a heavyweight panel of U-value 0.5W/m2 deg C containing 20% 6II1II glass in a cedar wooden frame. In addi tion I economic 'break points' at which the environmental performance of the roof and floor rather than that of the walls should be considered were examined.

Figure 'l The similarity of sections of these results, and, therefore, per113ps the freedom of designing for

the scene thermal consequences I for example I

25-2-7 over a range of storey heights, plan shapes, 5 Chrenko, F .A. 'Thermal Comfort' Heating and areas of glass etc should be considered. ventilating for a human environment. Institute The suggestion that a number of spaces of of Mechanical Engineers. London 1967 differing shapes and sizes, have the same Paper No 8. 'thermal capability' present itself. Comparisons 6 Allaway, P. H. 'Annoyance Factors in with Musgrove's work 42 on space Ventilu.tion Noise and Practical Control classifications are irresi.stible. Problems' . Heating and ventilating for a human environment. Institute of Mechanical Using this process a 2 Form Entry Junior School Engineers. London 1967. Paper No 9. has been designed (Fig 8) and is in the process of being built 43. 7 Doherty, C .H. 'Practices in the Domestic Field'. Heating and ventilating for a human environment. Institute of Mechanical Engineers. London 1967 Paper No 1. 8 Dale, K.W. 'Practices in the Commercial Field'. Heating and ventilating for a human

'~~~~ I environment. Institute of Mechanical Engineers. 1'''·!ltl'l London 1967. Paper No 15. 9 Taylor, F. M H. 'Applications of Factory-made Air-Cbnditioning Units'. Heating and Vf;ntilating for a human environment. Institute of Mechanical Engineers. London 1967. Paper No 3. Figure 8 10 Hardy, A.C. O'Sullivan, P.E. 'The building as a Climatic Modifier'. Heating and The Research and Development Cycle is into its ventilating for a human environment. second time around. Institute of Mechanical Engineers. London. 1967 Paper No 13. What then for the future? The plea, therefore, must be for simplicity in design and control. 11 Lamb, H.H 'Britain's climate, its For Design based on the simple principles which variability and some of its extremes'. Heating are often forgotten. For Design based on the and ventilating for a human environment. probabilistic view. Finally, for Design that is Insti tute of Mechanical Engineers. London mea surable . Then we must build more, monitor 1967. Session 3. Paper No 7. and wait. 12 Eccleston, W.H. 'Some basic considerations in the practice of heating, ventilating, and air conditioning'. Heating and ventilating for References a human environment. Institute of Mechanical Engineers. London. 1967. PaperN06. 1 'IES Code: Recommendations for good interior lighting'. Illuminating Engineering Society, 13 Scott, D.R. 'Education in Architectural London 1969. Environmental Engineering and Design' . Heating and ventilating for a human 2 Webb, C.G. 'Thermal comforts and effective environment. Institute of Mechanical temperature'. CIE Conference on sunlighting Engineers. London 1967. Paper No 16. in buildings. Newcastle Upon Tyne, 1965. 14 'Research in Action: An Integrated Design 3 Oosting, W.A. 'Onderzoek Naar de Study Applied to Schools Development' . Gel uidisolatie van Vkakglas ' . Report 706, Architectural Research and Teaching. Vol 1. 007, Technical Physics Service, TNOTH, No 2. November 1970. Delft, Holland, 1967. 15 Statutory Instrument. No 890. HMSO 1959. 4 Billington, N. S. 'The Working Environment' Heating and Ventilating for a human 16 Hopkin son f R. G. Longmore, J. Petherbridge, P. environment. Institute of Mechanical 'Daylighting'. Arnold Press, London. Engineers, London 1967. PaperNo 14. 17 Hardy, A.C. O'Sullivan, P.E. 'Insolation and Fenestration. Oriel Press, 1967

25- 2- 8 18 Markus, J. 'The function of windows: a 32 Lewi s, P. T. 'Real Windows' . Paper 2 reappraisal'. Building Science Vol 2, Conference on Building Acoustics, pp 95'-121. London 1967. University of Newcastle Upon Tyne. April 1970. Oriel Press October 1971. 19 Lynes, J.A. Burt, W. Jackson, G.K., Cuttle, C. 'The flow of light into buildings'. 33 Mitchell, H.G. 'Use of Heat Pumps in Illuminating Engineering Society Journal. air conditioning' . Electricity Council 1969. Vol 31, No 3 London 1966. 34 Page, J. K. 'Review of practice in the UK in 20 O'Sullivan, P.E. 'Air Conditioning 1'. environmental design'. Illuminating RIBA Journal, August 1970. Engineering' Society Con ference, York. 1970. Vol 153 (1962) Transactions. 21 Chandler, T. J. 'The climate of London' . (University College London). Hutchinson 1965. 35 'Integrated Design: a Case History'. The Electricity Council, London 1969. 22 O'Sullivan, P.E. 'Heat Islands in Cities'. Archi tectural Research and Teaching. May 36 Hardy, A.C. Mitchell, H.G. 'Building a 1970. Vol 1 No 1. Climate: The Wallsend Project' • Elecricity Council 1969. 23 Greenwood, P.G. 'The Interpretation of meteorological data for environmental 37 'Eastergate Primary School' Chichester, design'. PhD Thesis. September 1971 . Sussex. Building Specification. June 1971 . 24 Petherbridge, P. 'Sunpath diagrams and 38 Cadwaladr, R.O. 'The Liverpool Daily Post overlays for solar heat gain calculations' . and Echo Building'. RIBA conference Building Research Current Paper, Series 39. 'Ar,~hitecture and the Internal Environmer,t' Building Research Station, 1965. London September 1971. 25 Loudon, A.G. 'Window design criteria to 39 Gaytten, J. 'Simon Building - Stockport'. avoid overheating by excessive solar heat RIBA Conference ' Architecture and the Internal gains'. CIE Conference on sunU~ht::ng in Environment'. London September 1971. buildings. Newcastle Upon Tyne. 1965; 40 Harris, R.G. 'Bentall's Store - Bracknell'. 26 Langdon, F. J. 'Modern offices: a user survey' RIBA Conference 'Architecture and the National Building Studies Research Paper 41 . Internal Envirortnent' . London September HMSO, London 1966. 1971. 27 Turner, D.P. 'Windows and environment' . 41 Sherratt, A.F.C. 'Air conditioning system Pilkington Advisory Service (McCorquodale deSign for buildings'. Proceedings of the and Co Ltd) St Helens 1969. Joint Conference held at University of Nottingham, March 1969. Elsevier 28 Daws, L F. Penwarden, A.D. Walter, G.T. Publications Ltd 1969 . 'The visualisation technique for the study of air movement in Rooms'. Journal of the 42 Musgrove, J. Doidge, G. 'Room Institute of Heating and ventilating Engineers Classification' . Architectural Research and Vol 33. April 1965. pp 24-28. Teaching. Vol 1 No 1 May 1970. 29 Black, FA. Milroy, F.A. 'Experience of 43 'Integrated Environmental Design: a air condi tioning in Offices'. Building fea sibili ty study for School Buildings' Research Current Paper, Series SI. Gloucestershire County Council Architects Building Research Station, Garston 1966. Department. 30 Milbank, N. 0 'An investigation of energy consumption and cost in large air conditioned buildings: an interim report: . IHVE/BRS Symposium on 'Thermal Erv ironment in Modern buildings: aspects affecting the design team' . February 1968. 31 Hardy, A.C. O'Sullivan, P .E. 'Building a Climate'. Electricity Council. London 1967.

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