Eco-Friendly Houses

One of the things that we hear a lot from clients is “we want our house to be eco-friendly”. With issues of sustainability, climate change, wastage, and our impact on our environment being regularly discussed in the media, it’s only natural that an ‘eco-friendly’ home would be in our minds and on our wish-lists. But what exactly is an eco-friendly house? And how can we as architects help clients to define and achieve their goals?

First, it’s important to boil down to exactly where your concerns and priorities lie. Are you wanting to achieve specific targets such as carbon-neutral or Passivhaus status? Do you want to consider the ecological impacts too (ie on flora and fauna)? Do you simply want to use energy efficiently, or do you want to take a more holistic approach considering spatial requirements, the construction process, energy use, resources, embodied energy, light pollution, chemicals, indoor air quality, local skills, recycled materials…the list can go on and on.

For some clients these might be easy questions to answer, whilst others may need more help based on what is reasonable, local planning policies, whether the brief or design ambitions are at odds with the sustainability goals, and what the budget can accommodate. We are here to guide, educate and support your aspirations.

As designers, we believe that we have a responsibility to consider the impact that our designs have on the environment, but these impacts can be mitigated through different approaches:

Fundamentals

Most importantly, we view sustainability as something inherent in design, rather than just a tacked-on technology. As such, when we design your home we will consider:

• solar gain – how orientation can affect which spaces will benefit from heating from solar radiation, and how this may change throughout the day and across the year. This can help reduce the requirement for artificially heating rooms, but conversely must also consider the need for cooling if overheating is a risk
• natural light – orientation, glazing, room size and external shading will be taken into account to create optimal lighting conditions in different internal environments, thereby reducing the need for electric lighting
• thermal mass – what your house is made of can impact how the internal environment responds to external temperature changes. For instance, dense materials like concrete have high thermal mass, so they can store a large amount of heat and release it slowly to the rest of the house. Lightweight construction (ie a timber-frame) has lower thermal mass and therefore cannot be used so effectively as a heat store. Thermal mass can be utilised to keep buildings cool in summer and warmer in winter
• building fabric – we will address levels and type of insulation required to reduce the need for additional heating / cooling. A house with high levels of insulation, good quality glazing, and good air tightness will lose and gain less heat, therefore requiring less input from additional sources (ie central heating, air conditioning etc)
• building size – ultimately, the more you build, the greater the potential impacts. Therefore we work with you to achieve a balance of efficiency and spatial enjoyment. We also consider what the external envelope is like – a sprawling house will have a larger surface area (and therefore greater opportunity for heat loss, as well as a greater demand for building fabric), than a simple cube-like house of the same volume

Technology

To supplement the sustainable design principles that run through our architecture, we also address how technologies can be used to reduce the demand for energy or resources, use them more efficiently, or generate them on site:

• ventilation – MVHR (mechanical ventilation with heat recovery) can be used to greatly reduce heat loss due to traditional ventilation; it removes warm stale air from the house and uses it to heat incoming fresh cool air. It can stabilise internal temperatures, humidity, and CO2 levels, whilst improving air quality and reducing pollution (including pollens, allergens, VOCs etc)
• renewable energy / heating – hot water and heating can be supplied using air or ground source heat pumps and boreholes; heat is extracted from the air or ground and passed through a heat exchanger to heat water for use in the house. Photovoltaic panels can also be used to generate renewable electricity on site, reducing or replacing the need for electricity from the national grid
• water – we can integrate rainwater and grey water (water from baths, sinks etc) harvesting solutions to reduce the demand for fresh mains water, for both internal and external uses

We often work with Mesh Energy – a local renewable energy consultancy firm – who can offer expert advice on energy usage and sustainable solutions, ensuring that the technology and architecture are integrated flawlessly.

In addition to these ‘big moves’, we can also guide you with regards to selection of more sustainable interiors, materials and products. For instance, we will specify responsibly procured materials (ie timber from sustainable, certified forests) and use locally-sourced where possible; we will consider whether reclaimed materials are appropriate or if products made from waste can be used (ie engineered timber products using sawmill offcuts and waste), and if we can select natural materials for your interiors. We will specify sanitaryware to reduce water usage and wastage, and can select products with low VOC content (ie paints, varnishes, adhesives, fabrics, carpets, plastic products etc) to improve air quality and reduce the risk of environmental contamination.

Wherever your ambitions sit on the ‘green scale’, we can help to define and achieve your eco-friendly credentials.