Designing Roofing and veranda for south facing wide house in the Gambia
We have bought another plot 30 x 25 at the end of one we already own 40x 20. The plot had a large house half way built which we have taken down most of as it was too many rooms. We want an open plan living space, three bedrooms at the back of house, one storey and want a low flung roof to look similar to lAfrican houses in the village.
The main thing I am worried about is that the main open plan living area is positioned south facing. I want to add a wide veranda to he front also and worried about the style of roof and keeping cool as much as possible. Do you have any ideas?
I have looked on your cite previously for suitable roofing materials and ways of keeping house cool, which has been really helpful, but now work is under way, really worried about trying level best to keep house as cool as possible plus plenty of light.
Hope you can help me .
Thank you Mandy
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Replies
The Gambia lies between 13 and 16 degrees north latitude. When you're that close to the equator the southerly orientation hardly makes a difference, certainly not a difference worth worrying about.
The big solar gains not well protected roof overhangs are going to come in the morning and evening, not the mid day. Avoiding unshaded western exposure helps limit late in the day gains, after the house is already hot. No west facing windows, maybe even installing a tall fence on the west side to keep the sun off the house during the mid to late afternoon would help.
Daylighting the house from the north side has the least amount of heat gain, but in the tropics the south side works too, and it changes with the season. As long as the roof keeps direct sun off the wall most of the middle part of the day it's fine to have window area there, far better than the west or east.
Highly reflective roofs that also have some thermal mass work well in the tropics, something like whitewashed concrete or tile. I have no idea how well that blends architecturally in the region though.
Mandy,
I suggest that you seek local advice.
In general, you want wide roof overhangs; windows that are completely shaded all day long; and good cross-ventilation from windows that open.
You may also want to consider a radiant barrier under your roofing.
If you plan to install an air conditioner, the details of your house would be different.