Reading a Landscape Plan Before You Approve It

Most homeowners approve a landscape plan they cannot fully read, and then discover during construction that what they pictured and what was drawn were different things. It is avoidable with about twenty minutes of attention.

Look at the levels before the pretty parts

Plans usually carry spot elevations: small numbers with a decimal at various points. They are heights relative to a datum, often the finished floor of the house or an established point on the property.

The important question is which way the numbers fall. Water goes from a higher number to a lower one. Trace the route from the house outward and confirm the numbers reduce as they move away from the structure. If they do not, ask where that water is intended to go and expect a specific answer.

Find the drainage on the drawing

Ask where the drains are, where the pipe runs and where it discharges. On a well-prepared plan these are drawn. If drainage is not on the plan, it is not priced, and it will arrive later as a change order or not at all.

Also check the downspouts. A plan that reshapes the whole garden but leaves roof water discharging beside the foundation has left the largest single source of water out of the design.

Check the plants at mature size, not planting size

This is the single most common regret. A plan showing tidy circles at comfortable spacing usually shows plants at installation size. Ask what each is at maturity, in width as well as height.

Two specific things to watch for. Anything close to hardscape whose roots will lift it in ten years. And screening planted at final spacing, which looks sparse for years, versus screening planted closer for immediate effect, which then needs thinning. Both are legitimate choices; you just want to know which one you are buying.

Read the hardscape dimensions against real furniture

A patio drawn at a given size will contain a drawn table and drawn chairs comfortably. Measure your actual table. Add room to push a chair back and stand up, which is more than people picture, and room to walk behind someone who is seated.

The best version of this check is not on paper at all. Ask for the footprint to be marked out on the ground with paint or chalk before anything is cut, put your own furniture on it, and walk around. Changes at that stage are free.

Look for what is specified underneath

The plan shows the surface. The specification should say what is under it: base depth, material, compaction, reinforcement in concrete, drainage behind walls, footing sizes.

If those numbers are absent, you cannot compare two bids meaningfully, because you do not know whether they are describing the same job. Two paver quotes can be thousands apart and both be honest, because one includes a driveway-grade base and the other includes a footpath-grade base for the same area.

Check the irrigation is zoned by water need

Plants with different water requirements on one valve means something gets overwatered and something gets underwatered, permanently, and no controller setting fixes it.

Look for drip in beds, spray or rotors only where there is genuine lawn, and separate valves where plant material differs. Ask what pressure the design assumes and whether it has been measured at your property rather than estimated, because a system designed for pressure the house does not have will never cover evenly.

Confirm what is not included

Read the exclusions carefully. Common ones that surprise people: permit fees, engineering, unforeseen ground conditions such as buried debris or old foundations, utility relocation, and haul-away of demolition material.

None of these are unreasonable exclusions. They become a problem only when nobody mentioned them until the invoice.

The question that tells you most

Ask whoever drew the plan why they made one specific decision on it. Why the patio is there and not ten feet left, why that tree in that spot, why the wall stops where it does.

A designer who walked your property will have a reason grounded in your sun, your grade and your drainage. A plan assembled from a template will get a general answer. You will know within one question which you are holding.

The symbols and lines you are looking at

Plans vary between designers but the conventions are broadly consistent.

• Circles of varying size are plants, usually drawn at or near mature spread. A cluster of small circles is ground cover or perennials, a large single circle is a tree.
• Numbers with decimals are spot elevations, meaning heights. Water flows from a higher number to a lower one.
• Dashed lines are usually something underground: pipe, conduit, a drain run, sometimes an existing utility.
• Hatching and patterns indicate surface materials, keyed in a legend.
• Arrows with a percentage or ratio indicate the direction and steepness of fall.

You do not need to read these fluently. You need to find them and ask what they mean where it matters, particularly the elevations and the dashed lines.

Comparing two bids that look different

The most common frustration is two quotes that are not comparable because they describe different scopes at different specifications. Build a simple table and fill it in for both.

• Square footage of each surface type.
• Base depth and material under each surface.
• Drainage: what, where, discharging to what.
• Wall heights, construction type, and whether drainage behind is specified.
• Plant sizes at installation, in container size.
• Irrigation: number of valves and what is on each.
• Demolition and haul-away: included or not.
• Permits and engineering: included or excluded.

Half of an apparent price difference usually resolves the moment that table is complete.

Phasing without painting yourself into a corner

Large projects are frequently better done in phases, and there is one rule that governs it: anything that goes in the ground belongs in the first phase, even if what sits on top of it is a year or three away.

Drainage, irrigation mains, electrical conduit for future lighting, gas sleeves for a future fire feature or outdoor kitchen. Running them now while the ground is open costs relatively little. Retrofitting them means cutting through the surface you built in phase one.

Ask the designer to mark what is phase-one infrastructure even if the corresponding feature is not being built yet.

Questions that reveal whether the plan is site-specific

Ask where the water goes in a heavy December. Ask why the patio is positioned where it is rather than ten feet to one side. Ask which plants on the plan will struggle against the west-facing wall. Ask what happens to the existing irrigation.

Someone who walked the property answers all four immediately and specifically. A plan assembled from a template produces general answers, and you will know within about one question which one you are holding.

Common questions