## 4 Evaluating the Indoor Luminous Environment and Visual Comfort Perception
### Current Lighting Design Assessment Strategies
#### 4.2.1 Assessment Methods under High Building Design LOD  
Assuming that the building systems are not yet defined, but the LOD of the building design phase is already high (LOD approximately between 300-400), the indoor visual \begin{table}
\begin{tabular}{l l l l} \hline \hline
**Metric** & **Guidelines** & **Advantages** & **Disadvantages** \\ \hline \(E_{h}\) & LEED, BREEAM, WELL, EN12464-1, EN17037 & Easy to monitor, measure and model; spatial lighting conditions provided. & Point in time dependent, analysis grid selection ambiguous, no human adaptation, light intensity at eye uncertain. \\ \(E_{v}\) & WELL & Easy to measure and model, light intensity at eye known. & Point in time dependent, analysis grid location ambiguous, no human adaptation, complex to considered. \\ \(DF\) & BREEAM, BS8206-2, DGNB, DGNB, DGN5034-1, EN17037 & Fast and easy assessment; spatial conditions provided. & Unique low light intensity condition evaluation, no directionality was assigned. \\ \(DA\) & n/a & Annual and spatial analysis, easy to model. & Dichotomous variable (1 or 0), No high light intensity risk considered, light intensity at eye uncertain, biased by the limits set. No high light intensity risk considered, light intensity at eye uncertain, biased by the limits set. No high light intensity risk considered, light at eye uncertain, no information on problematic areas, biased by the limits set. \\ \(cDA\) & n/a & Annual and spatial analysis, easy to model. & Light at eye uncertain, no directionality assessed, biased by the limits set. \\ \(sDA\) & LEED & Annual and spatial unitary index, easy to model. & Light at eye unknown, spatial distribution not assessment, biased by the limits set. \\ \(UDI\) & n/a & Annual, grid-based and spatial index, easy to model, hint on under-lit, day-lit and over-lit areas. \\ \(FVC\) & n/a & Annual and grid-based unitary index based on \(E_{h}\), easy to model, information on the amount of time at discomfort and comfort. \\ \(IVD\) & n/a & Annual and grid-based unitary index based on \(E_{h}\), easy to model, information on the intensity of discomfort. & Light at eye unknown, spatial distribution not known, human adaptation or variability not assessed, biased by the limits selected. \\ \(U_{o}\) & AS1680, DIN5035, NSVV, CIBSE, EN12464-1, CIE29.2, BS8206-2, WELL & Information on lighting distribution contrast. & Biased by extreme values, no other information on light, has to be coupled with another metric. \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Critical analysis summary of collected visual comfort condition metrics based on daylight intensity and distribution, highlighting their benefits and drawbacks. \begin{table}
\begin{tabular}{l l l l} \hline \hline
**Metric** & **Guidelines** & **Advantages** & **Disadvantages** \\ \hline \(DGP\) & EN17037 & Robust and reliable, considers both light intensity and contrast, accounts for directionality, gives rating and sensation information, light at eye known. & Complex and lengthy to model, not reliable under low illuminance conditions and less reliable with large contrast, unique moment in time and position, no human adaptation considered. \\ \(DGP_{v}\) & EN17037 & Still robust and reliable, accounts for directionality, gives rating and sensation information, easy to model and compute, can be computed annually. & No contrast considered, less reliable under low illuminance conditions, analysis grid selection ambiguous, no human adaptation considered. \\ \(UGR\) & CIE177, EN12464-1 & Accounts for light intensity, contrast and directionality, gives rating and sensation information, direct and diffuse light at eye known. & Unique moment in time and position, no human adaptation considered, not reliable when the sun is within the field of view. \\ \(ASE\) & LEED & Annual and spatial unitary index, easy to model, hint on high intensity problematic areas. & Light at eye uncertain, no directionality assessed, biased by the limits set. \\ \hline \hline \end{tabular}
\end{table}