How much should I budget for site work on a raw lot?

Site work is everything that has to happen to a raw lot before the house itself can rise: clearing and grading, bringing in power and water, putting in a well and septic where there is no city service, building a driveway and access, and engineering drainage. On a finished subdivision lot most of this is already done. On raw desert land it is not, and it lands in your budget first. The honest answer is that site work is the most variable line in a custom-home budget, and on a difficult parcel it can run from the tens of thousands into well over a hundred thousand dollars before a single wall goes up. The number depends almost entirely on the specific lot, so the goal of this answer is to show you what to budget for, not to hand you a figure to bank on.

What "site work" actually includes

When builders talk about site costs on a raw lot in our markets, they usually mean some combination of the following:

• Clearing and demolition. Removing brush, native vegetation, rock, and any existing structures. In Arizona this can also trigger native plant protection rules and dust-control requirements, so it is not always as simple as running a machine over the land.
• Grading and earthwork. Cut and fill to create a level building pad, plus any retaining walls. This is where a sloped or rocky lot gets expensive fast, because moving and compacting earth is priced by the volume and difficulty of the work.
• Utility extension. Running electric service from the nearest line to the home, and water where a municipal main is available. The further your building site sits from existing service, the longer and costlier the run.
• Well and septic. On rural land with no city water or sewer, you are budgeting for a drilled well and an engineered on-site wastewater (septic) system instead of a tap and a sewer connection. Both are permitted separately and both depend on conditions you cannot fully price until they are tested.
• Driveway and access. A culvert, a graded or paved driveway, and any right-of-way or encroachment work to connect the lot to the public road.
• Drainage and stormwater. Grading and retention to carry monsoon runoff away from the house. Arizona's adopted residential code requires the finished grade to slope away from the foundation, so this is not optional, it is engineered.

Why the range is so wide

Two lots that look similar from the road can carry very different site budgets. The biggest swing factors are:

• Slope and topography. A flat pad needs little earthwork. A hillside lot can trigger hillside-disturbance and grading rules, heavier structural engineering, and far more cut and fill.
• Soils and what is underground. Caliche (a cement-hard calcium-carbonate layer common in the desert), expansive clay, and collapsible soils all raise excavation and foundation cost. A geotechnical (soils) report is one of the first studies worth ordering, because it tells you what the ground will demand before you commit a budget.
• Distance to utilities. A parcel a quarter mile from the nearest power line carries a very different extension cost than one with service at the property line.
• Water and wastewater feasibility. Well depth is not knowable until you drill, and the septic system the soils require (a conventional system versus a more expensive engineered or alternative system) is set by a percolation or soils evaluation. Both are real unknowns at the budgeting stage.
• Access. A long private driveway across uneven ground costs far more than a short connection to a paved street.

How to put a working number on it

Because the variables are lot-specific, the right approach is to convert unknowns into studies before you finalize a budget. The studies that retire the most risk are a boundary and topographic survey, a geotechnical (soils) report, a percolation or septic feasibility evaluation, and written will-serve or service-availability letters from the utility and water providers. Each one costs a fraction of the surprise it prevents. Order them during due diligence, ideally before you close on the land, so the site budget is built on tested facts rather than optimism.

It also helps to separate the site budget from the house budget in your own planning. Lumping them together hides where the money is really going, and on many raw lots the ground is where the budget is truly decided. Keeping site work as its own set of line items lets you see the true cost of the parcel you are considering and compare two lots honestly.

Permits and fees are part of site work too

Site work is not just dirt and pipe. Grading and drainage permits, a septic permit from the county environmental department, well registration with the Arizona Department of Water Resources, and any driveway or encroachment permit each carry their own fee and review timeline. In unincorporated areas such as the Rio Verde Foothills the county, not a city, is the Authority Having Jurisdiction, and a septic clearance is typically required before the building permit releases. Build those approvals into both the budget and the schedule.

How Jematell Homes approaches it

We price the site and the house as two separate conversations, because on many of the lots we build, the site is where the real cost lives. Before we commit to a site budget we want the survey, the soils report, the septic feasibility, and the utility will-serve letters in hand, so the number reflects your actual ground rather than a generic allowance. We also sequence the grading, well, septic, and access permits so they do not stall the building permit. Because soils, well depth, and fee schedules all vary by parcel and change over time, treat any planning figure as a starting point and confirm the current requirements and costs with the local Authority Having Jurisdiction, your utility and water providers, and your licensed site professionals for your specific lot.