If you’re starting a new project, the first step is to set objectives for the comfort and health of you and your family, while also bearing in mind your future needs and the wellbeing of people who will live in the house after you.
This process starts by understanding what works for you. Objectives can be as simple as wanting to have warm feet in winter or being able to get out of bed in the morning without feeling cold. Ideally they will be flexible and adaptable to future conditions.
Personal preferences, levels of physical activity, and age have an impact on the conditions in which we feel comfortable. Some people naturally feel colder than others and therefore might need warmer rooms; others might be uncomfortable in an overly dry environment. You may have zero tolerance to external noise or prefer task lighting instead of uniform light.
The needs of a family with young children will be different to those of a retired couple, and it’s important to consider that your needs will change over time. Remember that young children and the elderly are more vulnerable to cold temperatures and poor indoor air quality.
The objectives that are important to you will have an impact on the strategies, methods and systems that are used in your project. For example, if you are a light sleeper, measures to isolate external noise may be a key component of your project. Concerns for your kids’ health and safety might lead you to emphasise the elimination of potentially harmful construction materials such as VOCs.
Quantifying your comfort and health objectives will help you to communicate them to design team members and suppliers of products or systems. This can facilitate testing during the design process and will allow you to make informed decisions about features and strategies. Once the house is completed you’ll be able to check whether or not you have achieved them.
Targets around comfort and health may look like one of the following examples:
- Temperature. I want living areas to remain between 20°C and 25°C year round and the sleeping areas to be between 18°C and 21°C.
- Humidity. I want humidity levels throughout the house to stay below 70%.
- Ventilation. I want bathroom extractors to have a ventilation rate of more than 60m³ per hour.
- Airtightness. If only manual ventilation is used, I want no more than 3 air changes per hour (ACH).
- Materials. I only want to use paints with less than 60 VOC grams per litre.
Temperatures and humidity levels can be determined using a simple thermometer and hygrometer (humidity meter). Even before the planning process starts, you can install these in your current home and refer to them when you and your family experience comfort or discomfort. This will help you quantify the ranges of temperature and humidity that work for you. Although objectives around noise and light levels can be quantified using decibels and lux respectively, in most cases it is easier to set qualitative criteria such as the following:
- I want to avoid the use of artificial light during daytime.
- I want a quiet home office that allows me to be productive in spite of the children playing nearby.
- I want bedrooms to face the quieter side of the property so external noise won’t disturb us at night.
The process of quantifying objectives can also be guided by the benchmarks that certification schemes have set previously. These have been tested and implemented by others in the past, and can provide a simple framework for decision making. The table below explains how comfort and health criteria are addressed in each of the analysed tools, as well as the objectives and targets they have set.
Certification
scheme | How does it
address comfort and health objectives? | Comfort and health
targets |
Building Code | There are several clauses in the Code that relate to comfort and
health which aim to ensure that people who use the buildings can do so safely
and without endangering their health: - Clause
E3 focuses on internal moisture.
- Clause
G4 includes considerations around ventilation.
- Clause
G6 discusses airborne and impact sound.
- Clause
G8 talks about artificial light.
- Clause
H1 focuses on energy efficiency and contains minimum R-values for different
components of the thermal envelope.
| Performance targets are not set for residential buildings within the
Building Code. |
Living Building
Challenge | Buildings need to ensure all occupied spaces have operable windows. Each project must create an interior environment plan that demonstrates
compliance with a number of international standards and explains how it will
achieve an exemplary indoor environment. Specifies all the materials that have to be avoided during
construction. | The
Red List includes 22 materials and chemicals that can’t be used in the
project. |
Net Zero Energy | There are no mandatory comfort and health considerations as part of
the Net Zero Energy certification. | N/A |
Homestar | Energy,
comfort and health are combined in the weightiest category of the tool, which
accounts for 48% of the total points. Focuses
mostly on thermal performance from a whole-of-house perspective. Also
includes considerations around moisture control, sound insulation and
inclusive design. | Homestar
does not set explicit performance targets around comfort and health. |
Passive House | Heating and cooling demand and airtightness test results are two of
the three key standards that need to be met to achieve certification. To meet the specified heating and cooling demand, buildings are
expected to remain between 20°C and 25°C throughout the year. Additionally, there are requirements around surface temperature,
thermal bridging and air flow rates that must be achieved. All occupied spaces must have operable windows
and projects must demonstrate compliance with a number of international
standards on indoor environmental quality. All mechanical ventilation systems
must work inaudibly and draught-free. | Buildings need to achieve comfortable temperatures (20°C–25°C) with a
heating and cooling energy demand of less than 15kWh/(m²yr) or a peak heating
load of less than 10kWh/m². Relative humidity should be within a range of 30%–70%. Result of the airtightness test (also known as the blower door test;
see below) needs to demonstrate less than 0.6 air changes per hour. |
High Standard of
Sustainability (HSS) | In
addition to including quantitative targets around temperatures and humidity,
the HSS includes a checklist of design features aimed at improving indoor
environment quality. | Projects
need to comply with the following temperature and humidity levels: - living rooms temperature in winter
>18°C
- bedrooms temperature in winter >16°C
- living rooms relative humidity in winter:
40%–70%
- bedrooms relative humidity in winter: 40%–70%
|