In order to address the scientific questions posed in the international urban surface energy balance model comparison study it is necessary, and useful, to establish some model categories. Here four classifications are used, with the following sub-classes:

1. Vegetation inclusion:

a. Integrated: vegetation is within the tile that has the build facets so can interact/respond to the exchanges associated with this layer of the model.

b. Separate Tile: the vegetation and built parts of the surface are treated separately and do not interact until a layer above the surface scheme. The fluxes are a spatially weighted mean.

c. None: assumed to be no vegetation present.

2. Urban land surface scheme layers resolved :

a. Slab

b. Single layer

c. Multi-layer

3. Facets and aspects resolved :

a. Whole – individual walls, roof, road are not resolved.

b. Roof, Walls and roads are resolved but without orientation – therefore there are not sunlit and shaded facets resolved.

c. Roof, Walls and roads are resolved with orientation – therefore during the daytime there maybe sunlit and shaded facets.

4. Anthropogenic heat flux :

a. Internal Temperature: An internal temperature is prescribed which is used to calculate the other fluxes

b. Prescribed: flux value is prescribed

c. Modelled: all or components of the flux are modelled

d. None: the flux is assumed to be 0 W m-2 or not to exist.

In this presentation we will show the relative performance of the models within each of these classes from Stage 0 of model evaluation.