Project

Cooling Load Optimization & Design Guidance for a Villa in Saihat, Saudi Arabia

An energy simulation study for a villa in Saihat, Saudi Arabia — using DesignBuilder/EnergyPlus to identify the biggest contributors to cooling load and run a parametric study on wall insulation thickness to inform architectural decisions.

Energy, Building Performance & Sustainability

Location

Saihat, Saudi Arabia

Tools Used

DesignBuilder, EnergyPlus

Service Category

Energy, Building Performance & Sustainability

Project Type

Residential villa — cooling load analysis & envelope optimization

Case Study

Challenge

The villa's design needed to be checked against Saihat's hot Gulf climate before construction — the team needed to know which building elements were driving cooling loads the hardest, and whether the wall assembly could be optimized to cut energy use without adding unnecessary cost.

Approach

GreenBIMSource built a DesignBuilder/EnergyPlus model of the villa and simulated a full year of heating, cooling, and internal gains, breaking down the heat balance by source — glazing, lighting, equipment, occupancy, and solar gains — to identify where cooling load was coming from. A parametric study then swept external wall EPS insulation thickness from 150 mm to 300 mm, tracking both annual cooling electricity and total project capital cost at each step.

Result

Windows and lighting emerged as the largest contributors to heat gain, with solar gains through exterior glazing dominating the summer heat balance, while shading and sun angle naturally cut solar gains later in the season. On the envelope side, the parametric sweep showed cooling electricity and total capex both falling steadily as EPS thickness increased, with returns leveling off well before the 300 mm end of the range — GreenBIMSource recommended 250 mm as the practical target thickness. Combined with the load breakdown, the analysis pointed the design team toward two concrete moves — better solar shading and tighter lighting control — as the highest-leverage next steps for efficiency.

Deliverables

DesignBuilder/EnergyPlus full-year energy simulation
Heat balance breakdown by source (glazing, lighting, equipment, occupancy)
Parametric wall insulation study (cooling load vs. capital cost)
Shading and lighting-control recommendations

Analysis

3D architectural render of a villa courtyard with perforated screens, dining area, and pool loungers — Courtyard render of the villa, showing the perforated shading screens central to its passive design.

EnergyPlus internal gains and solar heat balance output by month, showing lighting, equipment, occupancy, and solar gains through exterior windows — Monthly heat balance by source — solar gains through exterior glazing and lighting stand out as the largest contributors.

Chart showing annual cooling electricity and total capital cost decreasing as external wall EPS insulation thickness increases from 150mm to 300mm, with 250mm marked as recommended — Parametric study of external wall EPS insulation thickness — both cooling load and total capex fall as thickness increases, with 250 mm recommended as the practical target.

EnergyPlus annual fuel breakdown by end use, showing cooling electricity dominating summer months — Annual fuel breakdown by end use — cooling electricity dominates the summer months, confirming it as the primary energy driver.

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