Landscape budgeting

Working with a Landscape Designer – Opinion of Probable Cost

Welcome back to our series on Working with a Landscape Designer. This post focuses on the third component in the design process – The Opinion of Probable Cost.


If you are just tuning in, you can find out what you missed by reading our past blogs:


Q: What is an Opinion of Probable Cost (OPC)?

A: The OPC is the designer’s assessment for how much the landscape development will cost. It is assembled at an early stage in the design process and usually updated throughout the project. While the OPC is a helpful tool, it should not be confused with a project budget.


Q: If the OPC is not my budget, what is its purpose?

A: The OPC is a tool used in the landscape design process to keep the designer accountable for budget and the client informed of the cost expectation. Many times the OPC directly influences the direction of the design process, thus making it a critical piece of the communication for the project.


Q: How accurate is the OPC?
: The margin of error can be relatively high in the early stages of the landscape design process. Typically, at this stage, we start with a 20% provisional cost / margin of error. As we refine drawings, select materials and finishes, and have a more concise plan, that number is lessened to 10%.


Q: How is the OPC calculated?

A: The designer uses their experience, industry knowledge, and past projects to provide their opinion for the cost of the project. The project is broken down into major groups and line items (such as pools and fountains, paving, landscape, fencing, etc.), and then either a unit cost or lump sum figure is calculated for those items.


Q: What happens if your OPC does not meet my initial budget parameters?

A: In my experience the landscape budget for a project can be very vague and speculative. It is typically not a true reflection of the expectation and design program for the project.

Here is how we move forward:

  1. Determine the validity of the original budget. Is the project over-designed or is the budget under-estimated?
  2. Decide on a course of action: (a) do we increase the budget to meet the plan or (b) do the expectations and the design program need to be changed to meet the budget requirements?


Q: Matthew, I imagine budget is a difficult conversation for most people. What do you tell clients who have sticker shock?

A: (laughs). You imagine right, Heather. Money can be a rather sensitive but very important topic. When clients experience sticker shock, I first like for them to understand that they are not alone… often times, this is just part of the design process. First we dream together and then we have to come back to reality to process, rank, and prioritize those dreams.

I recently read a great article by Kris Wetherbee of Luxury Pools. In the article Kris advises clients to allow the designer to lead them in the right direction for their project, saying, “You may have specific ideas for your backyard, but remember that a designer has the experience and ability to know what works well and can guide you toward the right decisions.” So when the opinion of probable cost is more than expected, that is ok. That is one of the reasons you hired us. Allow us to advise you and talk it through with you to determine the best possible solution for you.


Q: Do you have any advice for helping clients create a more realistic budget before starting the design process?

A: You know, landscape budgeting is really tough, because the entire initial budget the client brings to the table is usually based purely on speculation. I mean sure, you can say I would like a pool, but how big is that pool, what amenities does it include, what are the finishes, how does it transition from one space to the next once you starting laying it out on paper? These are all components that significantly affect the cost that cannot necessarily be determined without going through the creative process. In my opinion, it is almost always better to know what it would look like and what it would cost if your expectations could be met. How else will you know what is most important or most appealing to you, if you do not really know what your options are?

In terms of figuring a more realistic budget from the start, I would say that it is important to set realistic expectations. Understand what your expectations are and the cost that are involved in achieving those expectations. Make a list of the non-negotiable items for your project, prioritize your list and think ahead—are you willing to “phase in” these different items and areas to spread the cost over time? I would also urge you to realize the difference in the cost associated with instant gratification vs. planting for growth. Lastly, be realistic and make sure you are basing your budget on your context. Understand that it will cost exponentially more to landscape a one-acre lot than a 10,000 sqft city lot. Another great piece of advice from Wetherbee, “be flexible with your budget… plan in terms of a price range rather than an amount.”


Q: If the OPC is approved, what is the next step?

A: Once we have the plan with the overall form, function, and aesthetic expectations in line with the budget and expected cost, we can move forward into what we call Design Development. This is the phase where we really narrow down on the details of the project. This is where we determine finishes, vendors and suppliers, special paving patterns and other details. The Design Development is where we take the project from a conceptual thought to a realized plan for implementation.


Feeling ready to get started on your outdoor design project or have a specific question you would like answered? Send us an email!

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