-critical component of any building, since it both protects the building occupants and plays a major role in regulating the indoor environment. Consisting of the building's roof, floor slabs, walls, windows, and doors, the fabric controls the flow of energy between the interior and exterior of the building.

The building fabric must balance requirements for ventilation and daylight while providing thermal and moisture protection appropriate to the climatic conditions of the site. Fabric design is a major factor in determining the amount of energy a building will use in its operation. Also, the overall environmental life-cycle impacts and energy costs associated with the production and transportation of different envelope materials vary greatly.

One of the most important factors affecting fabric design is climate. Hot/dry, hot/humid, temperate, or cold climates will suggest different design strategies. Specific designs and materials can take advantage of or provide solutions for the given climate.

A second important factor in fabric design is what occurs inside the building. If the activity and equipment inside the building generate a significant amount of heat, the thermal loads may be primarily internal (from people and equipment) rather than external (from the sun). This affects the rate at which a building gains or loses heat. Building Configuration also has significant impacts upon the efficiency and requirements of the building fabric. Careful study is required to arrive at a building footprint and orientation that work with the building fabric to maximize energy benefit.

- A combi (instantaneous) boiler is the most widely used combi boiler type and directly heats incoming mains cold water to supply your taps, showers and other hot water points. It operates as an ‘instantaneous’ boiler but at somewhat higher efficiencies than the standard combi boiler. Also, it is a variant of the Instantaneous combi boiler type above and is designed to give you better performance through the internal storage of heated water. The stored water also can give you better initial water supply from cold water mains on first turning on the tap. Once the stored heat has been used, this boiler will tend to operate as an ‘instantaneous’ type. Dependent upon the make and model, the improvement in heated water delivery will depend upon the size of water store, and this can vary widely.

Combi boilers, often referred to as combination boilers, are a form of condensing boiler. Combi boilers generate water on demand for your taps and central heating from within the boiler unit. Combi boilers are easily the most popular boiler type, accounting for over 50% of all new boiler sales within the UK. Having said this combi boilers are not suited for everyone and it is important to understand whether a combi boiler is right for you. Most traditional central heating systems (regular boilers) store the boiler heated water in a copper cylinder in the airing cupboard to provide domestic hot water. Combi boilers do not require this hot water storage saving you valuable space and reducing heat loss from the previously stored water. As a result combi boilers can be more energy efficient than other boiler types. Central heating systems incorporating combi boilers have fewer overall components. Combi boilers take their cold water feed direct from your mains supply. By installing a combi boiler the cold water feed tank, often housed in the loft, is also not required this can also save storage space and reduces the number of components in the system simplifying any combi boiler system installation. As combi boilers do not store hot water they heat water direct from the cold mains supply as you use it, this gives you the equivalent of a power shower without the need for a pump.

One small disadvantage with a combi boiler is that although a continuous flow of hot water is constantly available, the water flow rate from combi boilers is not likely to be as good as with a traditional storage cylinder, particularly in winter. The power rating of the combi boiler needs to be matched to your family’s heating requirements. Heating water ‘on demand’, a major advantage of a combi boiler, improves energy efficiency but limits the volume of water available at any moment. Because the combi boiler is fed directly with mains cold water, it is important to establish that the minimum design water pressure is available otherwise the boiler performance will suffer. For this reason a combi boiler is not always suitable in all areas and a site survey is often required to confirm the suitability of the water supply

- a decrease in the amount of heat contained in a space, resulting from heat flow through walls, windows, roof and other building envelope components.

• 1. Calculates the total exposed elements area
• 2. Calculates the heat loss coefficient for each element (U-Value x Area)
• 3. Sum the heat loss coefficients together and divide by total exposed area to get the average U-Value
• 4. Calculate the ratio of Total Exposed Area/Volume = At/V
• We use this ratio At/V and Table 1 (TGD L) to determine if the average U-Value is less that the Maximum permitted U-Value. We also need to check individual U-Value Limits
• Roofs = 0.25
• Walls = 0.37
• Ground Floors = 0.37
• (No maximum U-Value limits specified for Doors and Windows).

• Air-Conditioning The process of bringing air to a required state of temperature and humidity, and removing dust, pollen and other foreign matter.
• Central Heating A heating system in which a number of rooms or spaces are heated from a central source.
• Convector A heating device in which the air enters through an opening near the floor, is heated as it passes through the heating element and enters the room through an upper opening.
• Hot Water Heating. The circulation of hot water through a system of pipes and radiators either by gravity or a circulating pump.
• Panel Heating Coils or ducts installed in wall, floor or ceiling panels to provide a large surface supply of low intensity heat.
• Radiant Heating. A heating system in which only the heat radiated from panels is effective in providing the heating requirements.
• Warm Air Heating .A warm air heating plant consisting of a heating unit (fuel-burning furnace) enclosed in a casing, from which the heated air is distributed to various rooms of the building through ducts.

The heating controls in your central heating system are designed to allow you to control the temperature of your home and to use energy efficiently. For the controls to be effective you should be able to turn them on and off and they should rapidly react to any changes in room temperature. If you have thermostatic controls in each room they should provide varying levels of heat in different parts of your home, at levels set by you, and stop your boiler from working when it is not needed.

Using heating controls correctly is the easiest way to keep your rooms at a comfortable temperature. And in doing so, they'll help to reduce your household's fuel bills and CO2 emissions, too.

What makes a full set of heating controls? A time programmer and a room thermostat or combined programmable room thermostat instead of separate programmer and room thermostat. Plus A cylinder thermostat if your home has a regular condensing boiler with a hot water cylinder and thermostatic radiator valves (TRVs).

- is energy generated from natural resources—such as sunlight, wind, rain, tides and geothermal heat—which are renewable (naturally replenished). Renewable energy technologies include solar power, wind power, hydroelectricity, micro hydro, biomass and biofuels. In 2006, about 18% of global final energy consumption came from renewables, with 13% coming from traditional biomass, such as wood-burning. Hydropower was the next largest renewable source, providing 3%, followed by hot water/heating, which contributed 1.3%. Modern technologies, such as geothermal, wind, solar, and ocean energy together provided some 0.8% of final energy consumption. The technical potential for their use is very large, exceeding all other readily available sources.

Renewable energy technologies are sometimes criticised for being intermittent or unsightly, yet the market is growing for many forms of renewable energy. Wind power is growing at the rate of 30 percent annually, with a worldwide installed capacity of over 100 GW, and is widely used in several European countries and the United States. The manufacturing output of the photovoltaics industry reached more than 2,000 MW in 2006, and photovoltaic (PV) power stations are particularly popular in Germany. The majority of renewable energy technologies are directly or indirectly powered by the sun. Renewable energy is derived from natural processes that are replenished constantly. In its various forms, it derives directly from the sun, or from heat generated deep within the earth. Included in the definition is electricity and heat generated from solar, wind, ocean, hydropower, biomass, geothermal resources, and biofuels and hydrogen derived from renewable resources.

While the primary responsibility for compliance with the building regulations rests with designers, builders and building owners, building control authorities have powers to inspect design documentation and buildings as well as powers of enforcement and prosecution where breaches of the regulations occur. There are heavy penalties, including fines and imprisonment, for breaches of the regulations. In addition, you may find that when it comes to selling your property, you will have difficulties if you cannot satisfy the purchasers' solicitor that the requirements of the regulations have been met.

- environmental concerns and the rising cost of fuel mean that there is an increased focus on the minimisation of energy use during the natural occupational life of a building. The thermal performance of the building envelope can make a significant contribution to reducing the overall building energy usage.

The relative thermal performance of concrete, timber and steel framed houses has been deliberately confused by marketeers. This confusion has been added to by professional ‘experts’, some of whom have made false and misleading statements from environmental platforms. Lightweight framed structures and heavyweight concrete structures have different thermal characteristics. Lightweight structures heat up quickly and this leads many people to believe that they are ‘warmer’. In fact, they also cool down quickly - more quickly than concrete structures which act as a heat reservoir, absorbing heat and returning it to the environment over a period of hours. This storage capacity is a product of concretes ‘thermal mass’ and it produces a ‘thermal bonus’ in that it can store heat from the suns rays which enters through windows and returns the heat over a period of 6 hours, reducing heating requirements.

A recent study carried out by the concrete industry at European level, in preparation for input into the EU Environmental Performance of Buildings Directive (EPBD), assessed model buildings for thermal performance using dynamic thermal modeling and inputting actual meteorological data from the north pole to the equator. Two separate thermal software packages gave virtually identical results, showing that on average concrete structures have a 5% thermal advantage in house construction and up to 20% advantage in office type buildings. These results are simply a scientific verification of what is already a well documented phenomenon.