Fix the soil.
The grass follows.

Because a number without a measurement is a guess, and a guess that turns out to be wrong on site helps nobody. Two lawns of the same size can be very different jobs depending on grass type, how compacted the soil is, how much of the property is actually treatable turf, and how much access there is. The quote you get is measured, not estimated.

Three things. Treatable square footage — beds, drives and gravel come out of that number. Grass type, because it changes both the timing and the seed. And current soil condition, because a badly compacted lawn may need a double aeration pass where another needs one. Jay Cooper measures from satellite imagery first, then confirms it on site before anything is finalised.

Both, honestly. It works, and it takes longer. A synthetic nitrogen application greens a lawn in about a week by feeding the plant directly. Building soil organic matter feeds the soil instead, which is slower and does not reverse the moment you stop. Year one you will see a difference. Year three the lawn holds water through a dry August without much help. If you need a green lawn by next Saturday, this is the wrong service.

Certification means the material has been tested — for maturity, for stability, for contaminants, and for whether it is actually finished compost rather than partially decomposed material that will rob nitrogen from your lawn as it finishes breaking down. "Compost blend" is an unregulated marketing phrase. It can mean certified compost mixed with something cheaper, and frequently does.

The sand does the structural work: coarse particles hold open pore space that water can drain through, which heavy clay does not do on its own. The compost keeps the mix biologically alive and stops it setting up hard. Sand on its own over clay is a well-known way to make something closer to concrete — the ratio and the compost fraction are what make the blend work rather than backfire.