Building physics is the science that deals with the physical processes in and around buildings — particularly heat transfer, moisture transport, air movement and sound. The goal of building physics is to achieve a healthy, comfortable and energy-efficient indoor climate.
The Four Pillars of Building Physics
Building physics covers four main topics:
- Heat — how heat flows through building elements (conduction, convection, radiation) and how insulation limits this
- Moisture — how water vapour moves through constructions and where condensation can occur
- Air — how air currents affect the indoor climate (ventilation, airtightness, draughts)
- Sound — how sound is transmitted and insulated (building acoustics)
Application
Building physics is essential in every construction project:
- New build — energy performance calculations are based on building physics principles
- Renovation — when retrofitting insulation, condensation must be prevented
- Damp problems — a building physicist analyses the cause of mould or condensation
- Energy ratings — EPC calculations are based on building physics parameters
Key Parameters
| Parameter | What it measures | Unit |
|---|---|---|
| **R-value** | Thermal resistance of a construction | m²·K/W |
| **U-value** | Thermal transmittance of a construction | W/m²·K |
| **Lambda (λ)** | Thermal conductivity of a material | W/m·K |
| **Vapour resistance (μ)** | Resistance to vapour diffusion | — |
Related Terms
- Insulation
- Building acoustics
- Indoor climate
- U-value
- Condensation
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