Part L Services

Criterion 1: Achieving an acceptable Building CO2 emission rate

This involves the calculation of a predicted carbon dioxide emission rate from the building and compares this with a building with identical geometry and functions but with nominal specifications similar to minimum standards. A naturally ventilated building will need to emit 23% less, an air conditioned building 28% less than a building built to nominal specifications.

Emissions represent only those from providing the main building services (heating: space and water, cooling, ventilation and lighting).

Thus a building built to the minimum requirements for fabric and services (Criterion 2) will not be compliant and in the event of the predicted emissions being unacceptable we will provide guidance on changes to the specification which will achieve compliance. Probable areas for improvement could be:

We will discuss with you the suitability of the different options so that the most appropriate and cost effective changes can be implemented. One of the most effective ways of reducing the fuel consumption cannot be assessed simply from design specifications as it relates to the quality to which the building is constructed and is assessed through an (obligatory for buildings over 500m2: see Criterion 4) air tightness test. We will discuss with you a target value which will be used in the calculation.

To derive the CO2 rating we will require the following categories of data:

Building Geometry

Building Services

The following will be required for every system and area it serves

Where present, we will require details of

We will assume that any data you provide is accurate, it will be assumed that key data is verified during/post construction by Building Control.

The greater the detail you are able to provide, the lower CO2 figure will result. iSBEM will assume worst performance from a generic type of system. Where the specific product is known then its performance specification will most likely represent an improvement over the generic value.

We realise that all this information may not be available in which case we will make assumptions and advise you of these. Where a significant benefit can be made by a better specification we will advise you.