General requirements for energy audits

I. The following principles shall serve as the basis for performing energy audits:

1. Audits shall be based on measurements and collected data.
2. Each individual surface area will be measured with a margin of error of about five per cent.
3. An energy conservation measure will be a suggested construction activity, a recommendation to install or configure a device or automated equipment differently. It can also be a suggestion for the consumers to change their habits unless it lowers their standard of living.
4. The audit shall propose a minimum of three technically feasible energy conservation measures. The costs will not be taken into account when making these suggestions. If possible, the simple payback period and lifespan of the measure will be provided.
5. The interrelation between energy conservation measures (and possibly the need for co-implementation) will also be specified.
6. The recommendation to make the transition to local heating will only be made if the quality of district heating is not good or is very expensive and if the residential building is not located in a compulsory district heating area. If renovation or construction of a district heating network or boiler house is planned for the near future, it must be specified.
7. When submitting information, the table form provided does not necessarily have to be followed. However, it is necessary to submit the required data, when available, for at least three years. Data may be submitted on the whole year (not necessarily on each month separately).
8. It must be possible, on the basis of the data submitted in the audit, to use the heat balance formula in simplified form for the last full calendar year.

Heat balance formula (in simplified form; last full calendar year):
Q total expense (according to meter or heating expense) = Q expense for building shell + Q expense for ventilation + Q heating hot water

II. In order to prepare an energy audit report for an apartment building all of the following should be determined and written down:

1. The date of the audit and the outdoor temperature
2. The name, address, telephone number and the e-mail address of the auditor
3. Description of the measurement instruments (type of device, precision, and the time when the measurement was performed)
4. The name of the housing association, the addresses of the building (and the address of the association)
5. Registry codes for the association and the building
6. The name, the address, the telephone number and e-mail address of the contact person in the housing association or in the building council
7. The registry number of the building (if one exists)
8. The year of construction
8.1 The year of renovation (along with the name of renovation company and what was done)
9. The volume heated in the residential building
10. The number of apartments in the building
11. Area heated within the apartments (where available)
12. Net height of the apartments (where available)
13. Average indoor temperature of the apartments during the heating period, as indicated by a survey, specifying the number of apartments surveyed (if possible)
14. Average temperature of the apartments on the day of the audit, as indicated by measurements taken at random, specifying the number of apartments in which measurements were taken
15. Value for degree-days corresponding to the location, derived on the basis of climatic data [such as published in the publication ´Eesti kliima teatmik ehitajatele´ (publisher: Eesti Ehitusteave 2000)]
16. Existing U-values for building shell and windows determined from the project/database, or from cross-sections made and calculated
17. Parts of the building shell which could be insulated, for example:
- external walls
- abutting walls
- loft ceiling and attic floor, insulating gable roof
- unheated ceiling of the basement
- ”look-out” basements
- insulated surfaces that have rooms behind them that are not heated
18. Parts of the building shell which are hard to insulate such as, for instance, the side walls of roofed galleries
19. Surface areas of windows in the rooms that are heated. If possible, the area or proportion of old windows in apartments and staircases should be shown.
20. Surface area of windows in unheated rooms (such as the cellar)
21. Surface area of doors and hatches
22. Description of the state of systems that have a bearing on energy use. In this section the following could be included:
- frames, the building shell
- a more detailed description of ventilation systems and random inspection (advisably on the basis of measurements). If they exist, results of measurements are provided
- heating and hot water
- electricity
- gas
- water and sewerage
- pictures, illustrations
23. Total Q (which is the total expense of heat) according to the heating (and electricity) meter or according to fuel expenses
24. Total heat losses through shell ( - Q building shell expense) – calculated on the basis of the area and the estimated U-values
25. Q expense of ventilation – if possible verification measurements should be taken, evaluated and calculated
26. Heat needed for heating water according to the data obtained from the housing association and/or on the basis of some other method approved by the auditor ( - Q making hot water)
27. An initial Heat Balance Formula should be prepared if possible. Afterwards, the balance of the sides of the equation and the accuracy of the values of the variables should be analysed. If necessary, estimates should be adjusted and individual values corrected. Finally, an Adjusted Heat Balance Formula will be formed.
28. The results of the energy conservation measure will be calculated and analysed (e.g. Q expense for building shell after application of measure x) and written into a chart.
29. The building’s annual consumption has to be summarized in table form (starred fields must be filled out):
30. If possible, the building’s monthly consumption (as available) should also be summarized in table form