The fabric minimises heat transfer between the building's interior and the outside world. A comfortable temperature inside the envelope is likely to be warmer or cooler than the ambient temperature outside, so limiting the exchange between them limits the energy needed to maintain the internal temperature.
Modern building fabric is well insulated to prevent direct transfer of heat energy by conduction, and also airtight to prevent air flowing in and bringing the outside temperature with it.
The services are designed around the efficiency of the fabric. The insulation of an energy efficiency building considerably cuts the need for heating or cooling when compared to older buildings, but the airtightness requires a ventilation system to maintain air quality and to prevent overheating during summer.
A control system like Atamate monitors the interior and only activates services as they are needed, as well as integrating the different features of energy efficient buildings so they complement each other. For example, building controls will automatically turn off an extractor fan if someone opens a window.
The more energy efficient the building design, the better the efficiency that can be achieved by the control system. However, a control system can still improve energy efficiency in existing buildings with poorly insulated fabric.
Because an energy efficient building does not need central heating, all of its energy can usually be supplied by electricity. Not requiring a connection to mains gas saves on construction and maintenance costs, and has the further advantage that generating electricity involves the emission of far less carbon than burning gas.
The building can be made even more efficient if it is possible to generate some of the energy it uses onsite, such as by generating electricity with photovoltaic cells or using solar thermal panels to heat water.
Because the building fabric conserves the internal air temperature, energy-efficient buildings use a much more responsive heating system than conventional buildings. A typical design would install electric heaters in each room which are only active when someone is in the room, focusing energy use on where it will affect the comfort of the people in the building.
The best cooling option depends on a building's location and use. Passive cooling is usually sufficient for a home in a temperate climate, using a combination of motorised windows and a building design that channels airflow through the building. Mechanical air conditioning may be necessary if a large amount of heat is generated in a building, such as if it is located in a warm climate or houses servers. Atamate can maximise the efficiency of the air conditioning by using passive cooling techniques as much as possible, and by preventing the air conditioners running while the windows are open.
The principle behind ventilation is to maintain high air quality inside the building envelope using the minimum volume of incoming air that needs to be heated or cooled. An energy efficient building continuously monitors air quality in all rooms using controlled vents and fans to replace the internal air only in the rooms where it needs replacing.
In most energy efficient buildings, the service that requires most energy is water heating. Atamate integrates hot water production with the heating and ventilation to maximise energy efficiency across different services. Insulation of hot water pipes is another component of energy efficiency as it prevents heat energy being lost from the hot water into the building envelope and contributing to overheating.
A full refurbishment involves improving the insulation and airtightness of the fabric and upgrading to more energy efficient building services. However, deep retrofits are expensive and intrusive, and are prohibited in many UK buildings with protected status.
Simple fabric upgrades such as loft insulation, window upgrades and draft proofing improve the efficiency of the building, especially when combined with placing the services under control. Atamate’s wireless system can be installed in any type of building to control its services.
Atamate's sensor network provides continuous input to a building's energy efficiency software, informing bespoke solutions when considering how to make buildings more energy efficient. Atamate can be fitted to existing buildings and used to find the possible methods for improving energy efficiency of buildings. A retrofit can then be planned around upgrading the specific services or parts of the building fabric that offer the most benefit for the least cost.