ST. MARY MAGDALENE CHURCH OF ENGLAND

This particular primary school was designed having the effect of daylighting in mind.This primary school was built in 1960 for 480 children to replace the old school destroyed during the War.The site (Fig. 8) is divided into two blocks, the first phase, built for 320 children and a further 160 places provided in the second phase.The first block is rectangular in shape with the entrance from the main road only.It is approximately level, uniformly 0.5 m above the street level.The site included old foundations and a bomb crater, which occurred in the position of the new boiler house.The site necessitated two-storey planning and it decided to divide the street horizontally, with infants on the ground floor, juniors on the first; each with their own assembly hall. The staff wing is common to both, and all dining is in the ground floor assembly hall.The floor level of this ground floor hall was dropped 0.9m below general level, to provide the additional headroom, the entrance hall thus forms a 0.9 m stage to the hall due to the drop and is separated from the hall by curtains.

The part of the building, which I would concentrate on mainly on the subject of daylighting, would be the classrooms.(Fig. 9 & Fig. 10).In the classroom wings, a light steel frame of box columns and channel beams supports pre-cast, pre-stressed concrete floors and roots spanning at right angles to the windows.Tie beams at column centres are contained within the thickness of the floors, so that no beams project below the ceiling level.

The floors in the classrooms are thermoplastic tiles and wood block in assembly halls and heather-brown quarries in the kitchen and toilets.

The continuous glazing on both sides of the building on both levels offer fine views in and out of the classrooms. (Fig. 11).Solar gains are controlled to some amount on the south side of the classrooms by the inwards built openings, but the ratio of the size of the glazed area is greater than that to the wall which would be encouraging to daylighting, but a problem to overheating in the Summer.This school lacks the roof light system, which was not common in school buildings in the 1960s, but instead made use of the high level windows.Glare can be caused during the daytime by the view of excessively bright sky through the window, particularly if it is very close to places at which the school children have to look.It will be seen that very large windows are not in fact necessary to give good standards of lighting and there are ways in which the problems can be solved so that daylighting in schools can be enjoyed without reservation. The main cause of glare is stated as:

Whenever one part of an interior is much brighter than the general brightness in the interior.The most common sources of excessive brightness are luminaries and windows, seen directly or by reflection.Glare can have two effects.It can impair vision, in which case it is called disability glare (Fig. 12) and it can cause discomfort, in which case it is called discomfort glare (Fig. 13).Disability glare and discomfort glare can occur simultaneously or separately (1)

This clearly shows that both excess and less brightness are equally unsuitable in school buildings or in any building at all.

The assembly hall of the school (Fig. 14) has beams spanning across its width with pre-cast beams spanning parallel to the decking covered with felt roofing sheet.On the first floor, lightweight concrete blocks faced with a waterproof membrane and vertical cedar boarding is used for the walling whilst on the ground floor the panel walls are of brick with an inner skin of concrete blocks.The external brick facings are left alone whilst the steel frame is covered, externally with pressed aluminium casings. The exposed timber in the building is Gold Coast Mahogany, naturally polished.The plastered walls are treated with emulsion paint with the exception of the staircases.All these have great effects on the amount of internal reflected lights and could be greatly affected by the colours on main interior surfaces, particularly the ceiling.Where the furniture or workspace layout is fixed and is likely to remain so, the lighting can be related.

A very good example would be a library, which uses localised lighting between the book stacks with, perhaps, local lighting on the reading tables, and general lighting in the main circulation area. It has an advantage of improved appearance and more efficient lighting.the disadvantage is the lack of flexibility in the use of the room. It encourages one use only.

Except in special circumstances like sky darkened by a passing thunderstorm, this tolerable minimum condition will normally occur near the beginning and end of each day; in midday, the illumination level will be much higher.However, the effect of this will be partially compensated for by changes in the sensitivity of the eye and there is therefore a clear-out distinction between the tolerable minimum condition and where natural illumination falls below its minimum standard and artificial lighting has to be used.

Norman & Dawbarn stress that since sufficient natural light is seldom available during the whole of normal daylight working hours throughout the year, it is necessary to decide the percentage of working hours for which adequate lighting is to be provided. To cope with this, it has become customary in many countries to base daylighting design on what is termed tolerable minimum conditions.

Today, other environmental factors may demand equal consideration – solar gain in summer, fabric heat loss in winter, natural ventilation, the entry of noise and dirt from outside, the view in and out, the composition of the architectural facade.

The CIBS Code of 1984 states that some of the rooms appear to be fairly evenly daylit.In a deep side-lit room, the lighting in the depth of the interior looks very dull when compared with the lighting just inside the window. This is likely to occur when the depth of the room, from window to back wall, is greater than the limiting depth calculated from the expression:

D=2 w h

(h + w) (1 – R_B where D =limiting depth

W= width of room

H=height of window

R_B=area – weighted average reflectance of surfaces

If the room is lit from opposite sides, the limiting depth, calculated as above, may be doubled.(2)

The following illumination values are taken from the 1961 Code of the Illuminating Engineering Society. It was stated that it does not represent the official recommendations of the Department but will help to indicate relative values in different parts of the building.

– Building Bulletin – (3)

HOOK INFANTS AND JUNIOR SCHOOL, HOOK, HAMPSHIRE BY ARCHITECTS J.F. CAME, COUNTY ARCHITECTS DEPARTMENT, ESSEX- 1970

Following the Second World War, the progressive cause was taken up in earnest and Hertfordshire, under the direction of its Chief Education Officer, John Newsom, became the focus of attention.For John Newsom, education was inseparable from environment and in response to the unprecedented demand for new schools to cope with the post-War baby boom and to replace what was then considered outmoded Victorian buildings.

The Hertfordshire Architects pioneered the use of system building based on Gropius’s concept of pre-fabrication by components rather than units of structure.Some ideas can be gained from Hertfordshire architects ideological commitment to lightweight system building.Bruce Martin, one of the most theoretically inclined Architects in Hertfordshire states:

Bricks and stones, tiles and concrete are materials for defence against a hostile world …We must build lightly for a life of free and changing activity, for families with the space in which to grow as needs and ideas change – Martin (1)

Hampshire County Council has inevitably raised Architectural attention on the innovative designs upon which the Department’s reputation is based, but the ultimately grander design with which the Architects are involved is that of the public estate as a whole.

These estates comprise mainly of primary schools and secondary schools of which many have won recognisable awards.

The Hook Infants and Junior School was a prototype in its approach to the maintenance and refurbishment of school buildings and represents the first combined approach to building and site rationalisation with the aim of integrating two schools under one roof (Fig. 15).It is also aimed at upgrading an existing building to current teaching standards within the new schools brief.Another aim was to provide an energy efficient environment to contemporary standards for both new and existing structures. This school, which was built in the 1970s, has been extensively increased in size and remodelled considering the effects of daylighting by incorporating an electrically operated sliding roof in the courtyard.(Fig. 16)

The building was enlarged by extending each leg of the H-plan and adding a central glazed pitched roof, which runs the length of the building, thereby creating atria between the classrooms in each leg of the H-plan.On the first floor level under the atrium roof seats the staff room.The infants of the school are occupying the northwest part of the building whilst the juniors are occupying the southeast.

The occupants of the north end of the building would be experiencing coldness in the Winter whilst the occupants of the south end of the building can avoid glare and overheating with the aid of window blinds or adjustable shutters.In some circumstances, it is worthwhile introducing some device to reduce the brightness of the sky seen through the top of the window, as this will lower the level of illumination, which the occupants of the room will require.Other ways that these could be achieved is by having opaque or semi-opaque louvres fitted at the top of the window, prismatic or neutral tinted glass in the upper portion of the glazed area.Even with any of these methods it should be stressed that it is necessary to clean, repaint, ventilate and use sun controls when needed.

A studied energy record of the school building was carried out by the Architects Department, Essex County Council in 1986, 1987 and 1988, even though the school was completed in 1978 and the records are thus: –

Annual Energy Consumption (Kwh)

1986/1987 Electricity on peak 27,064 Kwh

1986/1987 Electricity off peak 4,600 Kwh

1986/1987 Gas 172,870 Kwh

1987/1988 Electricity on peak 30,306 Kwh

1987/1988 Electricity off peak 3,988 Kwh

1987/1988 Gas 149,924 Kwh

Estimated Catering Consumption

Electricity on peak 5,880 Kwh

Gas 37,800 Kwh

Actual Average Annual primary energy consumption (corrected from region and annual degree days to national 20 year DD average and to exclude catering) = 276 Kwh/M²

The Gross Floor Area= 1059m²

(excluding 92m² atrium)

Teaching Area: 64m²

Unheated Glazed Area: 92m²

Number of pupil places: 280

Cost of Building :£171,129 excluding external works

External Works: £46,879

Base Date :4th Quarter 1977

BNC/Gross Floor Area: E191.21/m²

Completed :1978

Energy and Building Statistics,

Architects Department, Essex County Council (2)

Although the glazing area is about 14% of the teaching area, there is no glare as the main window looks on to timber screens and is placed to restrict a direct view of the sky.

Another good example of old schools with very low lighting standards is Greenhead High School, Huddersfield (Fig. 17, Fig. 18).

It was found that the minimum daylight factor in many of its classrooms was well under 2% due to small-obstructed windows and dark interior surfaces.The walls had an average reflection factor of about 20% and the floor almost 10%. The steps taken were to improve the ventilation factor of the wall from 20% to 60% and of the floor from 10% to 40%.

This eventually had the effect of doubling the minimum daylight factor from 0.5% to 1%. The old windows were replaced from heavy frames to lighter sashes and the sills on the windows were lowered from 1200 mm to 900 mm high.This doubled the glazed area to about 20% of the floor area and the minimum daylight factor then rose to 2%.

Although Hampshire’s achievement is inspiring, it cannot be considered apart from the society in which it is produced.Teachers and children gave the impression that it is a pleasure to teach and learn in the building. But walk out into the surrounding housing estate.Unless you speak to someone whose child goes to the school, you will be told how awful it is – more like a garden centre, factory or railway station – the same familiar metaphor you encounter as responses to the Fleet Velmead School in the next chapter. It is tempting for the architects to dismiss such criticism as the typically ill-informed comments of a visually “illiterate” populace and to return to refining the steelwork details on the next job.The gulf between “professional” educated taste and popular taste in Britain is vast that it may appear naive to suggest that it can be bridged.