Independent consultancy company

Clean energy for a sustainable world


The project E-TOOL

supported by 

The overall objective of the E-TOOL is to develop a building energy rating tool and promote the implementation of the EU building performance directive with a focus on an operational and simple tool.
E-TOOL is developed as a common tool for European countries, accommodating regional climate conditions and regional practices of building construction.
The E-TOOL handbook is a guide for professionals, to identify energy savings in existing buildings, based on the actual energy consumption (operational rating) and to report the most cost effective saving measures to the building owner.
The E-TOOL handbook is a user’s manual for the E-TOOL calculation program.
Download the E-TOOL calculation program
The E-TOOL calculation program and the handbook can be downloaded from
Results of the rating of buildings with E-TOOL
The results of the E-TOOL rating comprises following items:
1. Guidelines for typical energy saving measures including costs estimations for different classifications of existing buildings.
2. Energy performance requirements after energy retrofitting, for different categories of buildings.
3. Bench-marking of energy consumption of different categories of existing domestic, commercial and public buildings.
Limitations in use
The E-TOOL is based on the operational rating method that requires transparent and representative data of the buildings.
The benchmarking of the energy consumption of buildings in based on a statistical evaluation of energy audits that have been performed with the present E-TOOL.
Further information on benchmarks is availible on
The E-TOOL is intended to be a simple and operational tool for energy rating of existing buildings.
E-TOOLSET methodology has three main parts.
· E-TOOL User Data Sheets
· E-TOOL Process
· E-TOOL Report
E-TOOL User Data Sheets
The E-TOOL User Data Sheets, are divided into two different columns.
Data collection:
· General data of the building: Location, Category, Shape and physical data,  Climatized Area
· Climate Data (Degree days)
· Heating, Cooling, Domestic Hot Water, Lighting, Envelope characteristics.
· Energy consumption: Based on metered consumption.
Selection of saving measures:
Typical saving measures in each country, such as
· Changing of boilers
· Changing of windows
· Insulation of walls
· Installation of solar panels
E- TOOL process
Internal calculations

The E-TOOL uses several correlations and saving coefficients to calculate the energy savings obtained with each saving measures.
Additional information
The E-TOOL needs several inputs values that will have to be defined by each country:
· Average consumption percentage of each use (heating, cooling…) depending on the type of building and the climatic zone.
· Price of saving measures: The E- TOOL will include the price of the saving measures for Spain, but as the construction market prices differ a lot between countries, each country should include their own construction prices.
· Energy prices and annual rate of increase.
· CO2 emissions of each fuel type.
E- TOOL report
The Final report is obtained after E-TOOL internal process and will include information about potential savings, initial investment, payback time and CO2 savings for each saving measures.
The E-TOOL user must select the best five saving measures, according to the payback time and the energy savings achieved. Then, the E-TOOL calculates:
· Total potential savings
· Total investment cost of energy saving measures
· Payback time of the energy saving measures
· Total CO2 savings
· Initial E-TOOL result
· Final E-TOOL result