There are two elements when considering Lighting levels for your new house.
- Electrical Power (Watts)
- Amount of Light (Lumens)
In the old days with incandescent bulbs it used to be simple, bulbs came in 40, 60 and 100watts and you were allowed up to 25 watts/square metre of floor space.
Now for your new build, in order to limit energy consumption, you are only allowed:
- Indoors 5 watts /sqm (5W/sqm)
- Outside 4 watts/sqm (4W/sqm)
- Garages 3 watts/sqm
This doesn’t mean you have to have a gloomy house.
Modern light fittings such as Compact Fluorescent Lamp (CFLs) and Light Emiting Diodes (LED) give much more light than Incandescent Bulbs.
The above power consumption figure are for the initial construction. (After handover you can add additional lights)
Probably the best way to think about lighting is to consider what task you are going to do.
Then look at how you will provide enough light in that area rather than the whole room.
Here are some suggested light levels for various tasks.
Under 10 lumens/sqm – Outside Security.
10-20 lumens/sqm – Conversation, Eating, Watching Television, General Circulation.
20-50 lumens/sqm – Cooking, Casual Reading, Bathrooms.
50- 100 lumens/sqm – Detailed Craft Work, Study.
A typical LED delivers around 80-100 lumens per watt so a single 10w LED will provide a high lighting level for a 10m2 room (1 watt/sqm)
For more posts see Electrical or Light Fittings