Although there is much to know about protecting a site during construction, that is mostly beyond the scope of this document.  There are a few simple ideas to look for.  Preserve whatever topsoil is already there.   Make sure and surface or underground water isn't going any place you don't want it to.  Desirable mature plants, especially trees take many years to replace, so it pays to treat them well.  In particular avoid disturbing their roots via digging or driving machinery over them.  Don't let your soil get washed away during construction, even if its lousy soil, because if you don't want it neither does your neighbor, nearby stream or sewer system.

Traditional American landscaping consisting mostly of turf grass is often a significant source of pollution (fertilizers, herbicides & gas mower exhaust) as well as significant use of water during the summer months.  The environmentally friendly landscaping eliminates most or all of the turf grass and  produces little or no pollution while also requiring much less summer water.  The components of an environmentally friendly landscape include:

• Good soil, or more specifically soil that your chosen plants want to grow in

• Plants suitable for your climate and placed in the correct place in your yard

Needless to say doing this is not without it's drawbacks, specifically that it is no longer possible to maintain your yard by machine, and  if you're looking for a place to play croquet, you have to go elsewhere.  On the other hand, few other plants require as much maintenance as turf grass.  Garden lovers tend to have a wide variety of plants that create interest throughout the growing season, but this isn't necessary to create a more environmentally friendly landscape since you can use limited number of very tough plants and just trim them when necessary.  Weeding is necessary until your garden plants squeeze them out, so the first couple years are more work than subsequent years.  Unlike turf grass, you can't use weed killer on them, because it will kill many plants also.  If you're planning on maintaining your own yard (as opposed to using a lawn service), a yard with no turf grass is no more work.

Landscapes tend to use a lot of water if you want them to look good, whether they are turf grass or perennials.  If you want to use less water, drought tolerant perennials can give you a more interesting landscape without using any water after the first two years.   

Since landscape water is only used during the summer,  over the course of the year, there tends to be more water use in the house than out, even if the house is very water efficient.  The issue for many areas is that landscape watering need is greatest during droughts, when reservoir water is at its lowest.  Those who want to keep their landscapes alive (and maybe looking good) during drought should consider a rainwater tank (see utilities).

To conserve water in the house, use low flow faucets and showerheads, and buy water efficient washers and dishwashers (see www.energystar.gov for listings).

Resources

Seattle DPD Green Home Remodel Guide - Bath and Laundry here.

Seattle DPD Green Home Remodel Guide - Landscaping here.

Note: apologies if the links don't work: the city moves this stuff around on occasion.