Data for Part L2

This tab deals with data describing the building’s heating systems for the purpose of the L2 Elemental Method.

Note that if the Whole-building (Office) Method is being applied, the heating system data must be re-entered in a different format under the tabs labelled ‘Office CPR…’

This list-box displays a list of heating systems serving the building. Add to the list using the ‘Add’ button and remove a system by highlighting it and clicking on ‘Remove’. Highlight a system to display or edit its data in the boxes appearing beneath.

An editable description of the selected system.

The fuel supplying the heating system. Select a fuel from the list. This will affect the calculated carbon intensities.

If there is just one heating system, enter 100%. If there is more than one, enter the percentage of the total heat output to the building that is supplied by the selected system when the building heating load is at its maximum. (Note: heating systems are treated in terms of heat output for the L2 Elemental Method, but in terms of heat input for the methods based on Carbon Performance Rating.)

Enter the gross efficiency of the selected system (kWh of heat per kWh of delivered fuel) when the building heating load is at its maximum.

If there is just one heating system, enter 100%. If there is more than one, enter the percentage of the total heat output to the building that is supplied by the selected system when the building heating load is at 30% of its maximum.

Enter the gross efficiency of the selected system (kWh of heat per kWh of delivered fuel) when the building heating load is at 30% of its maximum.

Tick this box if the selected system is a combined heat and power (CHP) system.

If the system is a CHP system enter its heat to power ratio (kWh of useful heat produced per kWh of electricity output). This is equivalent to the ratio of the thermal and power efficiencies of the CHP unit.

Beneath this label are displayed the calculated and required carbon intensities of the combined heating systems working at their maximum heat output, together with a PASS or FAIL indicator for the L2 Elemental Method heating systems requirement (ADL2 paragraph 1.25a). To obtain a PASS, the calculated value must not exceed the required value.

Beneath this label are displayed the calculated and required carbon intensities of the combined heating systems working at 30% of their maximum heat output, together with a ‘Required U-value adjustment factor’. This factor relates to an adjustment to the threshold on average building U-value set in the L2 Elemental Construction Trade-off Method (ADL2 paragraphs 1.14-1.16):

“In order to allow greater design flexibility, there can be a trade-off (in either direction) between the average U-value of the envelope and the carbon intensity of the heating system[s] provided that the rate of carbon emission is unchanged.” (ADL2 paragraph 1.32).

The Required U-value adjustment factor is the factor by which the required average building U-value is adjusted by the performance of the heating systems. A value less than one puts a more stringent requirement on average U-value.

This tab deals with areas of the building that are naturally ventilated and not served by mechanical ventilation or air conditioning. The data is only used by the L2 Whole-building Method as applied to offices. It is used to calculate a whole-building Carbon Performance Rating (CPR) which is compared with a required (target) value.

Tick this box if parts of the building are not served by mechanical ventilation or air conditioning.

These sub-tabs deal with systems serving the naturally ventilated area.

Within each tab the following data must be entered:

The input rating for the equipment referred to, expressed per square metre of treated floor area. Treated floor area excludes plant rooms, service ducts, lift-wells etc. Process requirements – those relating to activities not typical of the office sector – should be excluded from the treated area, together with the plant capacity, or proportion of the plant capacity, that is provided to service those areas (ADL2 paragraph 1.60d).

A category describing the extent to which facilities for monitoring and reporting are provided. Select from the list.

Tick each plant maintenance feature that applies.

Or in the case of the Lighting tab, enter values specifying the percentage of the floor area benefiting from time-based lighting control, occupancy-based lighting control, daylight control or daylight availability.

Beneath this label are displayed the calculated and required whole-building Carbon Performance Ratings of the mechanical ventilation system, together with a PASS or FAIL indicator for the L2 Whole-building Method mechanical ventilation system requirement (BRE Digest 457 page 5). To obtain a PASS, the calculated value must not exceed the required value.

This tab deals with systems providing mechanical ventilation only. The data is used by the L2 Elemental Method and the L2 Whole-building Method as applied to offices. In both cases the data is used to calculate a Carbon Performance Rating (CPR) which is compared with a required (target) value. In the case of the Elemental Method the CPR rating applies to the mechanical ventilation systems only. In the case of the Whole-building Method it includes the heating and lighting systems.

Tick this box if all or part of the building is served by such a system.

Tick this box if the proposed system is an alteration of an existing system. This may require a less stringent CPR value.

These sub-tabs deal with systems serving the mechanically ventilated area.

Within each tab the following data must be entered:

The input rating for the equipment referred to, expressed per square metre of treated floor area. Treated floor area excludes plant rooms, service ducts, lift-wells etc. Process requirements – those relating to activities not typical of the office sector – should be excluded from the treated area, together with the plant capacity, or proportion of the plant capacity, that is provided to service those areas (ADL2 paragraph 1.60d).

A category describing the extent to which facilities for monitoring and reporting are provided. Select from the list.

Tick each plant maintenance feature that applies.

Or in the case of the Lighting tab, enter values specifying the percentage of the floor area benefiting from time-based lighting control, occupancy-based lighting control, daylight control or daylight availability.

Beneath this label are displayed the calculated and required Carbon Performance Ratings of the mechanical ventilation systems, together with a PASS or FAIL indicator for the L2 Elemental Method mechanical ventilation systems requirement (ADL2 paragraphs G10-G12). To obtain a PASS, the calculated value must not exceed the required value.

Beneath this label are displayed the calculated and required whole-building Carbon Performance Ratings of the mechanical ventilation system, together with a PASS or FAIL indicator for the L2 Whole-building Method mechanical ventilation system requirement (BRE Digest 457 page 6). To obtain a PASS, the calculated value must not exceed the required value.

This tab deals with systems providing air conditioning. The data is used by the L2 Elemental Method and the L2 Whole-building Method as applied to offices. In both cases the data is used to calculate a Carbon Performance Rating (CPR) which is compared with a required (target) value. In the case of the Elemental Method the CPR rating applies to the air conditioning systems only. In the case of the Whole-building Method it includes the heating and lighting systems.

If both new air conditioning and mechanical ventilation systems are to be installed in a building, the system types and their treated areas should be dealt with separately and the appropriate CPR achieved for each (ADL2 paragraph 1.64). If the area served by a particular system is less than 200m² it may be ignored for the purposes of the Whole-building Office Method (BRE Digest 457 page 3).

Tick this box if all or part of the building is served by such a system.

Tick this box if the proposed system is an alteration of an existing system. This may require a less stringent CPR value.

These sub-tabs deal with systems serving the air conditioned area. The Heating, Heating Distribution and Lighting tabs apply only to the Whole-building (Office) Method.

Within each tab the following data must be entered:

The input rating for the equipment referred to, expressed per square metre of treated floor area. Treated floor area excludes plant rooms, service ducts, lift-wells etc. Process requirements – those relating to activities not typical of the office sector – should be excluded from the treated area, together with the plant capacity, or proportion of the plant capacity, that is provided to service those areas (ADL2 paragraph 1.60d).

A category describing the extent to which facilities for monitoring and reporting are provided. Select from the list.

Tick each plant maintenance feature that applies.

Or in the case of the Lighting tab, enter values specifying the percentage of the floor area benefiting from time-based lighting control, occupancy-based lighting control, daylight control or daylight availability.

Beneath this label are displayed the calculated and required Carbon Performance Ratings of the air conditioning system, together with a PASS or FAIL indicator for the L2 Elemental Method air conditioning systems requirement (ADL2 paragraphs G10-G12). To obtain a PASS, the calculated value must not exceed the required value.

Beneath this label are displayed the calculated and required whole-building Carbon Performance Ratings of the air conditioning system, together with a PASS or FAIL indicator for the L2 Whole-building Method air conditioning system requirement (BRE Digest 457 page 7). To obtain a PASS, the calculated value must not exceed the required value.

Click this button to access the user database of building regulations Building and System Data.

The database presents a list of entries each containing a complete set of building regulations Building and System Data. Its purpose is to provide a facility for storing data settings for later reuse.

Changes to the database and the project data only take effect when the OK button is clicked on exit. You may abandon the database session using Cancel.

Click on a database entry to select it.

The area on the right of the dialogue headed Building & System Data displays the data in the selected entry and allows you to edit it.

Saves the contents of the selected database entry to the database. Should you omit to click this button following edits a message will prompt you to save the data.

Copies the contents of the selected database entry to the project.

Copies the Building and System Data from the project to the selected database entry.

Creates a new database entry. The data is initialised with the data in the currently selected entry.

Removes the selected entry from the database.

Allows renaming of the selected entry. You can also rename an entry by double-clicking on its name.

Exits the database and saves any changes.

Exits the database without saving.

Exits the Building and System Data interface and retains the changes made.

Exits the Building and System Data interface and discards the changes made (with the exception of any edits saved to the database).