---
title: "Heat, ventilation, light, sound, orientation, moisture"
subject: "Building Technology"
chapter: 1
key: "semester_6/building_technology:building-considerations"
source: https://www.bctengineer.com/q/semester_6/building_technology/building-considerations
site: BCT Engineering
---

# Heat, ventilation, light, sound, orientation, moisture

Building Technology · Chapter 1: Functional Requirements of Buildings

- Asked in: 2071 Bhadra, 8 marks
- Video: [The ultimate guide to passive home design](https://www.youtube.com/watch?v=67jvUXjGt7g) — Archi notes
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_6/building_technology/building-considerations
- Whole chapter: https://www.bctengineer.com/md/semester_6/building_technology/chapter-1

## Question

Explain the consideration of heat, ventilation, light, sound, orientation and moisture movement in a building with sketch where necessary.

## Short answer

Design must control heat through insulation, shading, and orientation; ensure ventilation with cross openings or fans; provide daylight (window area at least 10% of floor, daylight factor 2-5%); and give sound insulation. Orient rooms by sun and wind, and prevent moisture with DPC, waterproof plaster, slopes, and drainage.

## Answer

#### Heat
Heat enters and leaves by conduction, convection and radiation. Control through orientation, insulation (low U-value), shading of windows, thermal mass, cavity walls, light-coloured roofs and cool roofs. The aim is thermal comfort of 21 to 27 °C.

#### Ventilation
Supply of fresh air and removal of stale air to supply oxygen, remove CO₂, odour and heat. Natural ventilation by cross openings (wind) and stack effect; mechanical by fans for kitchens, toilets, basements. Opening area is generally at least 10 % of floor area, as per the National Building Code.

#### Light
Daylight is preferred. Window area, orientation and shading give a daylight factor of 2 to 5 %. Artificial lighting is used at night and where daylight is inadequate.

#### Sound
Provide sound insulation (heavy walls, cavity, floating floors, double glazing) against outside noise and neighbours, and absorption to control echo and reverberation inside.

#### Orientation
Rooms are arranged by the sun path and wind direction: for example, kitchen in the east or north-east, living room and bedroom in the south, long side facing south.

#### Moisture movement
Rising damp, rain penetration, condensation and leaks cause damage. Prevent by DPC at plinth, waterproof plaster, roof slopes and flashing, cavity walls, drains and ventilation.

```text
 sun ->  [S windows + chhajja]
 wind -> [window]---room---[window] -> cross ventilation
 ======= DPC at plinth ======= 
```
A good design balances all these factors together.

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. Heat control includes:
   A. Orientation, insulation, shading, thermal mass
   B. Large west glass
   C. Dark roofs
   D. No insulation
   Answer: A. Reduces gain and loss. (Key point: Heat control)

2. Opening area is generally at least what fraction of floor area?
   A. 1 %
   B. 10 %
   C. 50 %
   D. 90 %
   Answer: B. NBC suggests about 10 %. (Key point: Ventilation)

3. Rising damp is prevented by:
   A. DPC at plinth
   B. Thin walls
   C. More plaster only
   D. Removing drains
   Answer: A. Damp proof course at plinth. (Key point: Moisture)

4. Typical placement is:
   A. Kitchen east or north-east, living and bedroom south
   B. Kitchen south-west
   C. Bedroom north
   D. Living west
   Answer: A. Based on sun path and wind. (Key point: Orientation)

## Related in Building Technology

- [Moisture movement through building components](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Amoisture-movement) — Building Technology, chapter 1, asked 7×
- [Moisture movement and condensation effects](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Amoisture-condensation) — Building Technology, chapter 1
- [Orientation and planning of a building](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Aorientation-planning) — Building Technology, chapter 1, asked 12×
- [Mechanical ventilation and building code](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Avent-mech-conditions-nbc) — Building Technology, chapter 1
- [Building types, mechanical ventilation, air flow](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Aairflow-078c) — Building Technology, chapter 1
- [Heat phenomena in building](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Aheat-phenomena) — Building Technology, chapter 1

## Related in other subjects

- [Distance consideration in intensity](https://www.bctengineer.com/question.md?key=semester_5%2Fcomputer_graphics%3Aintensity-attenuation-distance) — Computer Graphics, chapter 8, asked 2×
- [Define moisture content, superheated vapor, etc.](https://www.bctengineer.com/question.md?key=semester_2%2Ffundamental_of_thermodynamics_and_heat_transfer%3Amoisture-superheated-definitions) — Fundamental of Thermodynamics & Heat Transfer, chapter 3
- [Quality, moisture content, specific volume of mixture](https://www.bctengineer.com/question.md?key=semester_2%2Ffundamental_of_thermodynamics_and_heat_transfer%3Aquality-moisture-specific-volume) — Fundamental of Thermodynamics & Heat Transfer, chapter 3
- [Define saturation temp, subcooled liquid, degree of superheat, moisture](https://www.bctengineer.com/question.md?key=semester_2%2Ffundamental_of_thermodynamics_and_heat_transfer%3Asaturation-temp-subcooled-superheat-moisture-defs) — Fundamental of Thermodynamics & Heat Transfer, chapter 3