LIGHTING BASICS

Lighting is measured by the amount of luminous flux on a surface, called illuminance. It is expressed either in foot-candles (illuminance in a square foot) or in lux (illuminance in a square meter). An artificial light source is referred to as a lamp. Although lamps are commonly identified by their wattage, this does not describe the output of light. A watt is the measurement of energy consumption from a particular light source. So an incandescent lamp and a fluorescent lamp can have the same light output of foot-candles or lux while ranging dramatically in wattage. As an example, a 60-watt incandescent lamp has the same light output as a 15-watt fluorescent lamp.

Light coming from a single point source can, like direct sunlight, create dark areas of shadow around the pool of light it provides. A point source calls attention to the surface it is illuminating and highlights its inherent characteristics. Diffuse light, like that on a cloudy day, distributes light evenly and is not strong enough to create shadows. While this even distribution of light may be good in a working environment because it is easy on the eyes, it can seem a bit dull and lifeless over time.

An unshaded lamp or poorly positioned fixture with an exposed lamp can cause extreme brightness from a light source called glare. While not measurable, glare is easily recognizable. It can impair vision and induce discomfort as the eye usually squints to reduce the impact of its harshness. Veiling reflection is another type of glare that is caused by the brightness of

a light source reflecting off a shiny surface such as glass. A familiar example might be the reflection of a bright window on a computer screen. The well-thought-out distribution and location of light fixtures can reduce glare significantly.

TYPES OF LAMPS

Many types of lamps are available, each with specific characteristics for colour rendition, size, energy consumption, and lamp life. Juggling all the variables can be complex. To specify lamps correctly, designers should know their efficacy rating (1 = low/poor, 5 = high/excellent) as well as their correlated colour temperature and colour rendering index.

Correlated Color Temperature

Color Rendering Index (CRI)

NEW LIGHTING TECHNOLOGIES

Although fibre-optic and LED lighting technologies have been around for a while, they are now becoming more readily available to designers. Both lighting types are more energy-efficient than fluorescent lighting, but also much more cost-prohibitive. As the market continues to focus on energy efficiency, however, designers will see these technologies advance further and become more affordable.

Fibre-Optic Lighting

This technology relies on strands of acrylic cables to transmit light from the light source, called the illuminator, to the ends of the cables. The illuminator is simply a box with either a tungsten halogen lamp or a metal halide lamp of varying wattages. Tungsten halogen lamps are more common, while metal halide lamps are typically used for large installations. The ends of the acrylic cable are gathered in a bundle and placed in an aperture directly in front of the lamp. The illuminators should be conveniently located for easy access to relamp the fixtures. It is also important to note that the illuminators need ventilation to release the heat that is generated by the lamp.

Depending on the lighting design, there can be less than a handful of acrylic cables or hundreds of cables. The length of the cables can vary per installation, but as a general rule, they should not exceed 50 feet (15 meters) or light transmission will be compromised. The advantage of this system is that multiple lights can be located in difficult-to-access places, controlled by a single lamp inside the illuminator.

LED Lighting

Although light-emitting diodes (LEDs) use a fraction of the electricity and last up to ten times as long as fluorescent lamps, they are too costly for use in general lighting. LEDs are available in high intensities of red, green, and blue light, and the combination of all three coloured lights

Comparative Correlated Color Temperature

yields white light. Varying combinations of the three colours can produce a full spectrum of colour options. LEDs have the additional advantage of producing no heat. Currently, LEDs are used in interior design to create desired effects such as accenting a reveal or washing a wall with coloured light. As the technology advances, it will become more affordable and eventually be applied to general-purpose lighting.

LIGHTING TERMINOLOGY

Ballast: a small device that controls the flow of current by providing the required starting voltage and then reducing the current during operation.

Correlated Colour Temperature (CCT): spectral characteristic of a light source, measured in Kelvins (K). The lower the temperature, the warmer the (yellow/red) tones; the higher the temperature, the cooler the (blue) tones. sunlight at dawn has a colour temperature of 1900K while a uniform overcast sky is 6527K.

Colour Rendering Index (CRI): scale from 1 to 100 that describes the effect of a light source on an object or surface. The higher the index, the more natural and vibrant the object appears.

Dimming Ballast: Device used with fluorescent lamps to vary the output of light by the use of a dimmer control.

Efficacy, or Luminous Efficacy: Efficiency in which electrical power is converted to light. Efficacy measures the number of lumens emitted per watts consumed (lm/W).

Low-voltage Lamp: Incandescent lamp that operates with low voltage, ranging from 6 to 12 volts.

Luminance: Amount of light reflected or transmitted by an object.

Transformer: The device designed to raise or lower electric voltage.

MATERIALS USED FOR DAMP PROOFING (DPC)

There are various materials, which are used as damp-proof courses depending upon the location, economy and degree of damp proofing desired. However, while selecting a particular damp-proofing material, the following requirements of an ideal damp-proofing material should be remembered.

1. The material for DPC should be impervious and durable, i.e., the material should be effective during the useful life of the building.

2. The material should be capable of resisting both dead loads and superimposed loads without being disintegrated.

3. The material should remain steady in its position, without any movements, so that the walls overlying the DPC do not develop any cracks.

4. For DPC above the ground level, with wall thickness up to 40 cm, any material listed below for DPC can be used.

5. For DPC to be laid over larger areas, such as floors and roofs, and thicker walls, a DPC material that provides a lesser number of joints should be used, such as mastic asphalt, bitumen sheeting and plastic sheeting.

6. The material for parapet walls and in other situations where differential thermal movements are expected due to exposure should be of flexible material, like mastic asphalt, bituminous felt and metal sheets.

7. In water-retaining structures or situations, a jointless DPC should be provided to take care of the risk of leakage.

8. In the cavity or hollow walls, the cavity over the door or window openings should be bridged by flexible materials, like bitumen sheets, strips of lead and copper.

The materials generally used for DPC are listed below.

1. Flexible materials: Hot bitumen, bituminous felts, bituminous sheet, plastic sheet (polythene sheets), metal sheets of lead, copper, etc.

2. Semi-rigid materials: Mastic asphalt or a combination of materials or layers.

3. Rigid materials: Use of I-class bricks, stones, slates, etc.

Hot bitumen or hot asphalt

This is a flexible material, which is first heated and then spread over the bedding of concrete or mortar (i.e., over walls). This should not be applied in thickness less than 3 mm. Bitumen or asphalt forms an excellent damp-proof course, as it offers an impervious, indestructible and tough surface.

Bituminous felts (6 mm thick sheet or asphaltic felt)

This is also a flexible material, which is available in rolls of normal wall widths. For placing this in position, first a layer of cement mortar is laid on the brickwork and then DPC is bedded on it. An overlap of 10 cm in case of joints and full-width overlap in case of angles and crossings should be provided. Bitumen felt is capable of accommodating slight movements but cannot withstand heavy loads.

Sheets of lead, copper and aluminium (metal sheets)

These are used as membranes for damp proofing and are of flexible type.

Sheets of lead

The thickness of the sheet should be such that the weight of the sheet is not less than 20 kg/m2. These are spread on the walls and overlapped at the joints. The sheets of lead should be embedded in lime mortar and not in cement mortar (because cement chemically reacts with lead and destroys it). The surfaces of lead should be protected by a coating of bitumen against corrosion. DPC formed by lead sheet provides an impervious and highly resistant surface against lateral movements.

Sheets of copper (minimum 3 mm thick)

Like lead sheets, these are spread, lapped and jointed. They are embedded in lime or cement mortar. This is another excellent DPC material that possesses characteristics such as high durability, good resistance to dampness and high resistance against sliding action.

Sheets of aluminium

These can also be used for DPC but not as good as to lead or copper sheets. These sheets should be protected with a layer of bitumen.

Combination of sheets and bituminous felts

A lead foil is sandwiched between the sheets of asphalt or bituminous felt. This combined sheet is known as ‘lead core’ and DPC of this core possesses the characteristics of easy laying, durability, efficiency and economy.

Mastic asphalt

This is obtained by heating the asphalt with sand and mineral fillers. This is a semi-rigid material and forms an excellent impervious layer for damp proofing, i.e., DPC. However, it requires special care in its laying. Good mastic asphalt has many characteristics, such as high durability, excellent water-proofing quality and reasonable elasticity. This can withstand only very slight distortion and is liable to lateral movements under heavy pressures or very hot climates.

ALSO READ: Damp Proofing | Sources Of Dampness | Effects Of Dampness | Techniques And Methods | Uses

Bricks

Good dense bricks, which absorb water less than 4 per cent of their weight, are suitable as a DPC material at places where the damp is not excessive. The joints are left open. They are widely used for providing or inserting a DPC membrane in an existing wall.

Stones

Generally, dense and sound stones, such as granite, trap and slates, are laid in cement mortar in two courses to form an effective DPC. The stones are used for the full width of the wall. While laying the stones, care should be taken in breaking the continuity of vertical joints.

Cement concrete layers

A cement concrete layer, having mixed proportions 1:2:4 (1 cement:2 sand:4 aggregates) with waterproofing agents, is used as DPC at the plinth level. It is effective in stopping the water rising due to capillary action but allows the water to pass through the cracks, etc., and hence is suitable as DPC material where dampness is not in excess. The concrete layer is used as a horizontal main DPC in thickness varying from 4 to 15 cm followed by two coats of hot bitumen paint.

Mortar

It is used in two ways, either (i) as a bedding layer for taking up other types of DPC or (ii) as a waterproofing plaster. For the bedding layer, the mortar is prepared by mixing cement and sand in proportions 1:3 and adding slight lime to increase the workability. For waterproofing plasterwork, the mortar is prepared by mixing either of the following:

a. 1 cement:2 sand pulverized alum and soap water,

b. Cement: sand in proportions 1:3, with patented waterproofing material like pudio, dampro and sika. After applying this plaster in 2–4 cm thickness, it is painted with two coats of hot bitumen.

LIVING ROOMS

Of all the rooms in a house, the living room has the fewest constraints since it requires neither appliances, nor plumbing fixtures, nor storage. As a result, interior designers have a great deal of freedom in terms of the character and configuration of the space. The living room should be designed to reflect the particular lifestyle of a family.

Typical Furniture Dimensions

Specific functional requirements and the size and shape of the room will help set the agenda for selecting and arranging the most appropriate furniture. Below are the dimensions of typical living room furniture. Be mindful that the dimensions of specific pieces may vary from the typical sizes. Furniture that diverges widely in dimension from these examples may be uncomfortable and impractical, however.

DINING ROOMS

The configuration of the dining room is predicated on the size and shape of the dining table.  Otherwise, the dining room allows for a great deal of design flexibility. Once a formal room occupied primarily on special occasions, the dining room today lends itself to a wide range of interpretations and can accommodate a variety of lifestyles. The dining room can be an extension of the kitchen, a zone within a large living room, or a separate room organized around the specific rituals of enjoying a meal. Regardless of the configuration, the dining room should be immediately adjacent to the kitchen work areas for easy delivery and clean-up of meals.

DIMENSIONAL CRITERIA

Place Settings

The dimensions of a dining table relate directly to the area required for a place setting. the approximate area of a place setting is 24 inches (610 millimetres) wide by  15 inches (381 millimetres) deep. although the standard dimension for a placemat is 18  inches (457 millimetres) across, additional the area is allocated for serving dishes, wine bottles, and elbow room.

BATHROOMS

Options for bathroom configurations range from two-fixture powder rooms to five-fixture master bathroom suites. The diagrams below include the average sizes for bathrooms based on the number and position of fixtures. For all bathroom layouts, comfort and privacy are top priorities.

BATHROOMS LAYOUTS