Gorgeous Green House

The Renovation Journey of a 1940’s ‘Traditional’ to 2015 ‘Contemporary, Green & Gorgeous’

Gorgeous Green Architectural Design

4 Comments

Several years ago when I started talking about my dream of building a ‘green house’ a friend said “oh I saw one of those … a kind of hobbit house…really ugly”  So the first misconception to clear up is that green design has nothing to do with the aesthetics of the house!  Whatever your taste (hobbit-like or otherwise) one can incorporate green design principles.  Essentially it means building in harmony with the natural environment and cooperating instead of fighting with the regional climate.  Green building takes a passive approach which requires less energy to run once the building is erected. It’s also know as bioclimatic design, eco-design, eco-friendly architecture, earth-friendly architecture, environmental architecture and natural architecture.

This post will focus on the design of the building itself, not the technology or specific materials to be used.  I will cover those aspects separately.

My house is in Durban South Africa.  We have an average of 320 days of sunshine a year. Temperatures range from 16 to 25º C in winter and  23 to 33º C in summer.  However, before you consider relocating, the warm Mozambique current flowing along our coast and summer rainfall means we also experience high humidity which can be quite debilitating from December to March.  So here is what we have briefed the architect to design into the house:

WINDOWS

We want light (lots of) but not direct sunlight which would heat up the house and require us to put in energy guzzling air-conditioners so one of the easiest things to do is install tinted windowsCross ventilation is also a vital consideration.  Windows were planned so that each room would have opening windows on opposite sides of the room.  The most challenging areas were the downstairs bedrooms which open onto the passage .  Tricky to get cross ventilation as you can see from the drawing below.

Bedrooms tricky for cross ventilation. Pond has low opening windows to draw in cool air

We did three things; firstly designed opening windows above the doors and small high windows (second floor not in view) that open up into the passage.  The passage windows slide sideways rather than level in our out so there are no unattractive or dangerous protrusions in to the passage.

Whirlybird

Secondly we have put whirly birds into the roof of the passageway to draw the warm air up and out of the house. These are fantastic low tech gadgets that are used a lot in factories but surprisingly not in residential properties.  The third thing we did was put opening windows at ground level next to the pond to draw in the cool air as it crosses the water.  Thanks for this great tip Greg Seymour greg@go-green-consult.com

OVERHANGS, EYEBROWS, FIXED LOUVRES AND TREES

Sun pouring into a building is a costly thing to mitigate. Passive solar cooling eliminates the need for air conditioning. The image at the top of the  page shows the house as it faces North.  In Durban this is the hottest elevation.  Fixed louvres will cut the sun’s strength considerably without blocking light.  The verandahs are wide so that even in winter when the sun is lower  it won’t penetrate into the house.  Elsewhere on the building are ‘eyebrows’ to shade windows.  Best of all (though not strictly a design feature) are trees and shrubs next to the building.  Many are deciduous so in summer they are full of leaves when most shade is wanted and in winter the drop their leaves when a bit more warmth is welcome.

CONCRETE AND ROOF GARDEN

Example of roof garden with plants I will also use

A study undertaken by Canadian researchers found that green roof habitats were very effective in reducing a building’s energy demands.   The results show that a conventional roof absorbs solar radiation during the day, creating a high daily energy demand for cooling internal air spaces. In  contrast, the growing medium and plants of a green roof habitat reduce the heat flow through  the roof by providing shading, insulation, and evaporative cooling (shown in green below). It was found that the green roof habitat reduced the daily energy demand for cooling by a whopping 95%!!  (If you’re interested in the tech stuff that’s from 19.3  kWh or 7,080 British Thermal Unit (BTU) per m2 for a building under a conventional roof to 0.9 kWh or 324 BTU per m2 for a building under a green roof habitat). Thermal mass is the term given to material (usually concrete or stone) which will absorb heat and prevent its entry into the home.  Although there are eco-negatives associated with concrete because  of it production processes judicious use can swing its rating into a green category.  In our house concrete (a lot)  has been required to build the base for the roof garden.  Its payoff though is immense at  many levels.  More to follow on the wider range of green roof benefits and how to actually construct your own.

ROOF DESIGN FOR SOLAR PANELS

Albizia shading area of roof originally allocated for roof panel

Ensure you plan carefully for the location of your solar panels.  We were quite ignorant of how many we needed (24!) and initially made provision for only 8 on a section that also gets much shade from an ancient and huge Albizia adianthifolia.  Our main roof was pitched – but the wrong way – which has led to delays with approval of plans as we’ve had to switch the pitch direction to accommodate the panels.  In Durban one cannot make changes during the build without the risk of inspectors shutting down construction while you wade through approval bureaucracy so best to get it right up front.  We’ve had expert help from Trevor Wheeler of  http://www.solarsunsa.co.za/  and I strongly advise you get your solar needs properly specified from a specialist before you submit your plans.  More posts to follow on the process of determining what your solar needs are.

To sign up / ‘FOLLOW’ this blog click on said button (small black button bottom RHS in the leaf border) and follow instruction to get notifications of new posts

Advertisements

4 thoughts on “Gorgeous Green Architectural Design

  1. Very good idea Peter. Will definately do so.

  2. Hi Jane,

    It occurred to me that it would be great to display a number of “before” pics, if you have them.

  3. Dear Jane

    Wishing you the best with everything. Hope your dreams come true!

    Love Barbara

  4. Great post. Keep this up and you will be offering a LOT of useful information. Peter

What do you think?

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s